Discovery and technical validation of high-performance methylated DNA markers for the detection of cervical lesions at risk of malignant progression in low- and middle-income countries

BACKGROUND

Cervical cancer remains a leading cause of death, particularly in developing countries. WHO screening guidelines recommend human papilloma virus (HPV) detection as a means to identify women at risk of developing cervical cancer. While HPV testing identifies those at risk, it does not specifically distinguish individuals with neoplasia. We investigated whether a quantitative molecular test that measures methylated DNA markers could identify high-risk lesions in the cervix with accuracy.

RESULTS

Marker discovery was performed in TCGA-CESC Infinium Methylation 450 K Array database and verified in three other public datasets. The panel was technically validated using Quantitative Multiplex-Methylation-Specific PCR in tissue sections (N = 252) and cervical smears (N = 244) from the USA, South Africa, and Vietnam. The gene panel consisted of FMN2, EDNRB, ZNF671, TBXT, and MOS. Cervical tissue samples from all three countries showed highly significant differential methylation in squamous cell carcinoma (SCC) with a sensitivity of 100% [95% CI 74.12-100.00], and specificity of 91% [95% CI 62.26-99.53] to 96% [95% CI 79.01-99.78], and receiver operating characteristic area under the curve (ROC AUC) = 1.000 [95% CI 1.00-1.00] compared to benign cervical tissue, and cervical intraepithelial neoplasia 2/3 with sensitivity of 55% [95% CI 37.77-70.84] to 89% [95% CI 67.20-98.03], specificity of 93% [95% CI 84.07-97.38] to 96% [95% CI 79.01-99.78], and a ROC AUC ranging from 0.793 [95% CI 0.68-0.89] to 0.99 [95% CI 0.97-1.00] compared to CIN1. In cervical smears, the marker panel detected SCC with a sensitivity of 87% [95% CI 77.45-92.69], specificity 95% [95% CI 88.64-98.18], and ROC AUC = 0.925 [95% CI 0.878-0.974] compared to normal, and high-grade squamous intraepithelial lesion (HSIL) at a sensitivity of 70% (95% CI 58.11-80.44), specificity of 94% (95% CI 88.30-97.40), and ROC AUC = 0.884 (95% CI 0.822-0.945) compared to low-grade intraepithelial lesion (LSIL)/normal in an analysis of pooled data from the three countries. Similar to HPV-positive, HPV-negative cervical carcinomas were frequently hypermethylated for these markers.

CONCLUSIONS

This 5-marker panel detected SCC and HSIL in cervical smears with a high level of sensitivity and specificity. Molecular tests with the ability to rapidly detect high-risk HSIL will lead to timely treatment for those in need and prevent unnecessary procedures in women with low-risk lesions throughout the world. Validation of these markers in prospectively collected cervical smear cells followed by the development of a hypermethylated marker-based cervical cancer detection test is warranted.

Uncovering the genetic architecture and evolutionary roots of androgenetic alopecia in African men

Androgenetic alopecia is a highly heritable trait. However, much of our understanding about the genetics of male pattern baldness comes from individuals of European descent. Here, we examined a novel dataset comprising 2,136 men from Ghana, Nigeria, Senegal, and South Africa that were genotyped using a custom array. We first tested how genetic predictions of baldness generalize from Europe to Africa, finding that polygenic scores from European GWAS yielded AUC statistics that ranged from 0.513 to 0.546, indicating that genetic predictions of baldness in African populations performed notably worse than in European populations. Subsequently, we conducted the first African GWAS of androgenetic alopecia, focusing on self-reported baldness patterns at age 45. After correcting for present age, population structure, and study site, we identified 266 moderately significant associations, 51 of which were independent (p-value < 10-5, r2 < 0.2). Most baldness associations were autosomal, and the X chromosomes does not appear to have a large impact on baldness in African men. Finally, we examined the evolutionary causes of continental differences in genetic architecture. Although Neanderthal alleles have previously been associated with skin and hair phenotypes, we did not find evidence that European-ascertained baldness hits were enriched for signatures of ancient introgression. Most loci that are associated with androgenetic alopecia are evolving neutrally. However, multiple baldness-associated SNPs near the EDA2R and AR genes have large allele frequency differences between continents. Collectively, our findings illustrate how evolutionary history contributes to the limited portability of genetic predictions across ancestries.

Perspectives on common chronic diseases in adult cancer patients in South Africa

There is a rising noncommunicable disease (NCD) burden in low- and middle-income countries. Sub-Saharan Africa (SSA) bears a higher burden than the global average with South Africa (SA) enduring the highest regional burden. SA among other southern African countries also bears a high prevalence of HIV and other chronic communicable diseases. Having a perspective on common chronic diseases in the ever-increasing numbers of adult cancer patients in SA will inform our understanding of approaches to better manage them. This commentary reviews regional and national studies and data of low- and middle-income countries and particularly SA on the chronic infectious and NCD multimorbidity burden among adult cancer patients. It also reflects on the considerable health system challenges of managing discordant multimorbidity among adult cancer patients within the SA Public Health System. Despite the critical need to better manage the growing MM burden in general and particularly the high prevalence of discordant multimorbidity among cancer patients, there is a dearth of research into MM management generally and in LMICs particularly.

Biochemical progression free and overall survival among Black men with stage IV prostate cancer in South Africa: Results from a prospective cohort study

BACKGROUND

Men of African descent are disproportionately affected by prostate cancer (PCa), and many have metastatic disease at presentation. In South Africa (SA), androgen deprivation therapy (ADT) is the first-line treatment for stage IV PCa.

OBJECTIVE

To identify predictors of overall survival (OS) in Black South African men with stage IV PCa treated with ADT.

DESIGN, SETTING, AND PARTICIPANTS

Men diagnosed with prostate cancer (3/22/2016-10/30/2020) at Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg, were recruited for the Men of African Descent with Cancer of the Prostate study. We included men with newly diagnosed stage IV PCa treated with ADT who had a prostate-specific antigen (PSA) level drawn prior to initiation of ADT and had ≥1 PSA drawn ≥12 weeks after ADT start.

OUTCOMES MEASURES AND STATISTICAL ANALYSIS

We used Kaplan-Meier statistics to estimate OS and Cox regression models to identify predictors of OS.

RESULTS AND LIMITATIONS

Of the 1097 men diagnosed with prostate cancer, we included 153 men with stage IV PCa who received ADT and met PSA requirements. The median age was 68.0 years (interquartile range 64-73 years). Median OS from time of ADT initiation was 3.39 years (95% confidence interval (CI): 3.14%-noncalculable), while biochemical progression-free survival was 2.36 years (95% CI: 2.03%-3.73%). Biochemical progression (HR 3.52, 95% CI: 1.85%-6.70%), PSA nadir level >4 ng/mL (HR 3.77, 95% CI: 1.86%-7.62%), alkaline phosphatase level at diagnosis >150 IU/dL (HR 3.09, 95% CI: 1.64%-5.83%), and hemoglobin at diagnosis <13.5 g/dL (HR 2.90, 95% CI: 1.28%-6.56%) were associated with worse OS.

CONCLUSIONS

In this study, we identified factors associated with poor OS among Black South African men with stage IV PCa treated with ADT. These factors may be useful in identifying patients for upfront treatment escalation, including the use of docetaxel chemotherapy or escalation of therapy at the time of biochemical progression.

PATIENT SUMMARY

In this study, we found that high alkaline phosphatase level, anemia at diagnosis, and high PSA nadir after initiation of androgen deprivation therapy are associated with worse overall survival among Black South African men treated with androgen deprivation therapy for metastatic prostate cancer.

FGFR2 genetic variants in women with breast cancer

Black African populations are more genetically diverse than others, but genetic variants have been studied primarily in European populations. The present study examined the association of four single nucleotide polymorphisms (SNPs) of the fibroblast growth factor receptor 2, associated with breast cancer in non‑African populations, with breast cancer in Black, southern African women. Genomic DNA was extracted from whole blood samples of 1,001 patients with breast cancer and 1,006 controls (without breast cancer), and the rs2981582, rs35054928, rs2981578, and rs11200014 polymorphisms were analyzed using allele‑specific Kompetitive allele‑specific PCR™, and the χ2 or Fisher's exact tests were used to compare the genotype frequencies. There was no association between those SNPs and breast cancer in the studied cohort, although an association was identified between the C/C homozygote genotype for rs2981578 and invasive lobular carcinoma. These results show that genetic biomarkers of breast cancer risk in European populations are not necessarily associated with risk in sub‑Saharan African populations. African populations are more heterogenous than other populations, and the information from this population can help focus genetic risks of cancer in this understudied population.

Characterizing HIV status documentation among cancer patients at regional cancer centers in Malawi, Zimbabwe, and South Africa

INTRODUCTION

In East and Southern Africa, people with HIV (PWH) experience worse cancer-related outcomes and are at higher risk of developing certain cancers. Siloed care delivery pathways pose a substantial barrier to co-management of HIV and cancer care delivery.

METHODS

We conducted cross-sectional studies of adult cancer patients at public radiotherapy and oncology units in Malawi (Kamuzu Central Hospital), Zimbabwe (Parirenyatwa Group of Hospitals), and South Africa (Charlotte Maxeke Hospital) between 2018 and 2019. We abstracted cancer- and HIV-related data from new cancer patient records and used Poisson regression with robust variance to identify patient characteristics associated with HIV documentation.

RESULTS

We included 1,648 records from Malawi (median age 46 years), 1,044 records from South Africa (median age 55 years), and 1,135 records from Zimbabwe (median age 52 years). Records from all three sites were predominately from female patients; the most common cancers were cervical (Malawi [29%] and Zimbabwe [43%]) and breast (South Africa [87%]). HIV status was documented in 22% of cancer records from Malawi, 92% from South Africa, and 86% from Zimbabwe. Patients with infection-related cancers were more likely to have HIV status documented in Malawi (adjusted prevalence ratio [aPR]: 1.92, 95% confidence interval [CI]: 1.56-2.38) and Zimbabwe (aPR: 1.16, 95%CI: 1.10-1.22). Patients aged ≥ 60 years were less likely to have HIV status documented (Malawi: aPR: 0.66, 95% CI: 0.50-0.87; Zimbabwe: aPR: 0.76, 95%CI: 0.72-0.81) than patients under age 40 years. Patient age and cancer type were not associated with HIV status documentation in South Africa.

CONCLUSION

Different cancer centers have different gaps in HIV status documentation and will require tailored strategies to improve processes for ascertaining and recording HIV-related information in cancer records. Further research by our consortium to identify opportunities for integrating HIV and cancer care delivery is underway.

The South African breast cancer and HIV outcomes study: Profiling the cancer centres and cohort characteristics, diagnostic pathways, and treatment approaches

The South African Breast Cancer and HIV Outcomes prospective cohort (SABCHO) study was established to investigate survival determinants among HIV-positive and HIV-negative SA women with breast cancer. This paper describes common and unique characteristics of the cancer centres and their participants, examining disparities in pathways to diagnosis, treatment resources and approaches adopted to mitigate resource constraints. The Johannesburg (Jhb), Soweto (Sow), and Durban (Dbn) sites treat mainly urban, relatively better educated and more socioeconomically advantaged patients whereas the Pietermaritzburg (Pmb) and Empangeni (Emp) sites treat predominantly rural, less educated and more impoverished communities The Sow, Jhb, and Emp sites had relatively younger patients (mean ages 54 ±14.5, 55±13.7 and 54±14.3 respectively), whereas patients at the Dbn and Pmb sites, with greater representation of Asian Indian women, were relatively older (mean age 57 ±13.9 and 58 ±14.6 respectively). HIV prevalence among the cohort was high, ranging from 15%-42%, (Cohort obesity (BMI ≥ 30 kg/m2) at 60%, self-reported hypertension (41%) and diabetes (13%). Direct referral of patients from primary care clinics to cancer centre occurred only at the Sow site which uniquely ran an open clinic and where early stage (I and II) proportions were highest at 48.5%. The other sites relied on indirect patient referral from regional hospitals where significant delays in diagnostics occurred and early-stage proportions were a low (15%- 37.3%). The Emp site referred patients for all treatments to the Dbn site located 200km away; the Sow site provided surgery and endocrine treatment services but referred patients to the Jhb site 30 Km away for chemo- and radiation therapy. The Jhb, Dbn and Pmb sites all provided complete oncology treatment services. All treatment centres followed international guidelines for their treatment approaches. Findings may inform policy interventions to address national and regional disparities in breast cancer care.

Heterogeneous genetic architectures and evolutionary genomics of prostate cancer in Sub-Saharan Africa

Men of African descent have the highest prostate cancer (CaP) incidence and mortality rates, yet the genetic basis of CaP in African men has been understudied. We used genomic data from 3,963 CaP cases and 3,509 controls recruited in Ghana, Nigeria, Senegal, South Africa, and Uganda, to infer ancestry-specific genetic architectures and fine-mapped disease associations. Fifteen independent associations at 8q24.21, 6q22.1, and 11q13.3 reached genome-wide significance, including four novel associations. Intriguingly, multiple lead SNPs are private alleles, a pattern arising from recent mutations and the out-of-Africa bottleneck. These African-specific alleles contribute to haplotypes with odds ratios above 2.4. We found that the genetic architecture of CaP differs across Africa, with effect size differences contributing more to this heterogeneity than allele frequency differences. Population genetic analyses reveal that African CaP associations are largely governed by neutral evolution. Collectively, our findings emphasize the utility of conducting genetic studies that use diverse populations.

The Impact of HIV Infection on Neoadjuvant and Adjuvant Chemotherapy Relative Dose Intensity in South African Patients with Breast Cancer

INTRODUCTION

In the South African Breast Cancer and HIV Outcomes (SABCHO) study, we previously found that breast cancer patients living with HIV and treated with neoadjuvant chemotherapy achieve lower rates of complete pathologic response than patients without HIV. We now assess the impact of comorbid HIV on receipt of timely and complete neoadjuvant and adjuvant chemotherapy.

MATERIALS AND METHODS

Since June 2015, the SABCHO study has collected data on women diagnosed with breast cancer at 6 South African hospitals. We selected a sample of participants with stages I-III cancer who received ≥2 doses of neoadjuvant or adjuvant chemotherapy. Data on chemotherapies prescribed and received, filgrastim receipt, and laboratory values measured during treatment were captured from patients' medical records. We calculated the mean relative dose intensity (RDI) for all prescribed chemotherapies. We tested for association between full regimen RDI and HIV status, using linear regression to control for demographic and clinical covariates, and for association of HIV with laboratory abnormalities.

RESULTS

The 166 participants living with HIV and 159 without HIV did not differ in median chemotherapy RDI: 0.89 (interquartile range (IQR) 0.77-0.95) among those living with HIV and 0.87 (IQR 0.77-0.94) among women without HIV. Patients living with HIV experienced more grade 3+ anemia and leukopenia than those without HIV (anemia: 10.8% vs. 1.9%, P = .001; leukopenia: 8.4% vs. 1.9%, P = .008) and were more likely to receive filgrastim (24.7% vs. 10.7%, P = .001).

CONCLUSIONS

HIV status did not impact neoadjuvant or adjuvant chemotherapy RDI, although patients with breast cancer living with HIV experienced more myelotoxicity during treatment.

Characterizing HIV status documentation among cancer patients at regional cancer centers in Malawi, Zimbabwe, and South Africa

Introduction

In East and Southern Africa, people with HIV (PWH) experience worse cancer-related outcomes and are at higher risk of developing certain cancers. Siloed care delivery pathways pose a substantial barrier to co-management of HIV and cancer care delivery.

Methods

We conducted cross-sectional studies of adult cancer patients at public radiotherapy and oncology units in Malawi (Kamuzu Central Hospital), Zimbabwe (Parirenyatwa Group of Hospitals), and South Africa (Charlotte Maxeke Hospital) between 2018-2019. We abstracted cancer- and HIV-related data from new cancer patient records and used Poisson regression with robust variance to identify patient characteristics associated with HIV documentation.

Results

We included 1,648 records from Malawi (median age 46 years), 1,044 records from South Africa (median age 55 years), and 1,135 records from Zimbabwe (median age 52 years). Records from all three sites were predominately from female patients; the most common cancers were cervical (Malawi [29%] and Zimbabwe [43%]) and breast (South Africa [87%]). HIV status was documented in 22% of cancer records from Malawi, 92% from South Africa, and 86% from Zimbabwe. Patients with infection-related cancers were more likely to have HIV status documented in Malawi (adjusted prevalence ratio [aPR]: 1.92, 95% confidence interval [CI]: 1.56-2.38) and Zimbabwe (aPR: 1.16, 95%CI: 1.10-1.22). Patients aged ≥60 years were less likely to have HIV status documented (Malawi: aPR: 0.66, 95% CI: 0.50-0.87; Zimbabwe: aPR: 0.76, 95%CI: 0.72-0.81) than patients under age 40 years. Patient age and cancer type were not associated with HIV status documentation in South Africa.

Conclusion

Different cancer centers have different gaps in HIV status documentation and will require tailored strategies to improve processes for ascertaining and recording HIV-related information in cancer records. Further research by our consortium to identify opportunities for integrating HIV and cancer care delivery is underway.

Effects of Genetic Polymorphisms of Drug Metabolizing Enzymes and co-Medications on Tamoxifen Metabolism in Black South African Women with Breast Cancer

Clinical outcomes of tamoxifen (TAM) treatment show wide interindividual variability. Comedications and genetic polymorphisms of enzymes involved in TAM metabolism contributes to this variability. Drug-drug and drug-gene interactions have seldom been studied in African Black populations. We evaluated the effects of commonly co-administered medicines on TAM pharmacokinetics in a cohort of 229 South African Black female patients with hormone-receptor positive breast cancer. We also investigated the pharmacokinetic effects of genetic polymorphism in enzymes involved in TAM metabolism, including the variants CYP2D6*17 and *29, which have been mainly reported in people of African descent. TAM and its major metabolites, N-desmethyltamoxifen (NDM), 4-OH-tamoxifen, and endoxifen (ENDO), were quantified in plasma using the liquid chromatography-mass spectrometry. The GenoPharm open array was used to genotype CYP2D6, CYP3A5, CYP3A4, CYP2B6, CYP2C9, and CYP2C19. Results showed that CYP2D6 diplotype and CYP2D6 phenotype significantly affected endoxifen concentration (P < 0.001 and P < 0.001). CYP2D6*17 and CYP2D6*29 significantly reduced the metabolism of NDM to ENDO. Antiretroviral therapy had a significant effect on NDM levels and the TAM/NDM and NDM/ENDO metabolic ratios but did not result in significant effects on ENDO levels. In conclusion, CYP2D6 polymorphisms affected endoxifen concentration and the variants CYP2D6*17 and CYP2D6*29 significantly contributed to low exposure levels of ENDO. This study also suggests a low risk of drug-drug interaction in patients with breast cancer on TAM.

PAM50 intrinsic subtypes, risk of recurrence score and breast cancer survival in HIV-positive and HIV-negative patients-a South African cohort study

PURPOSE

Treatment decision making for patients with breast cancer increasingly depends on analysis of markers or systems for estimating risk of breast cancer recurrence. Breast cancer intrinsic subtypes and risk of recurrence (ROR) scores have been found to be valuable in predicting survival and determining optimal treatment for individual patients. We studied the association of breast cancer survival with the PAM50 gene expression assay in HIV-positive and HIV-negative patients.

METHOD

RNA was extracted from formalin-fixed paraffin-embedded specimens of histologically confirmed invasive carcinoma and was purified using the AllPrep® DNA/RNA FFPE kit, Qiagen (Hilden, Germany). The NanoString RUO PAM50 algorithm was used to determine the molecular subtype and the risk of recurrence score of each sample. The overall and disease-free survival were determined with comparison made among HIV-positive and -negative patients. We then generated Kaplan-Meier survival curves, calculated p-values and estimated hazard ratios and their 95% confidence intervals using Cox regression models.

RESULTS

Of the 384 RNA samples analysed, 98.4% met the required RNA quality standard and the specified QC threshold for the test. Luminal B was the most common PAM50 intrinsic subtype and 82.1% of patients were at high risk for disease recurrence based on ROR score. HIV infection, PAM50-based HER2-enriched and basal-like intrinsic subtypes, and high ROR were associated with poor overall and disease-free survival. HIV-positive patients with luminal A & B subtypes had significantly worse survival outcomes than HIV-negative luminal patents.

CONCLUSION

Aggressive tumour biology was common in our cohort. HIV infection, PAM50 HER2-enriched,basal-like intrinsic subtypes and high ROR score were associated with poor overall and disease-free survival. HIV infection impacted survival in patients with luminal subtypes only.

Regional Variation in the Tumor Microenvironment, Immune Escape and Prognostic Factors in Breast Cancer in Sub-Saharan Africa

The low overall survival rates of patients with breast cancer in sub-Saharan Africa (SSA) are driven by regionally differing tumor biology, advanced tumor stages at diagnosis, and limited access to therapy. However, it is not known whether regional differences in the composition of the tumor microenvironment (TME) exist and affect patients' prognosis. In this international, multicentre cohort study, 1,237 formalin-fixed, paraffin-embedded breast cancer samples, including samples of the "African Breast Cancer-Disparities in Outcomes (ABC-DO) Study," were analyzed. The immune cell phenotypes, their spatial distribution in the TME, and immune escape mechanisms of breast cancer samples from SSA and Germany (n = 117) were investigated using histomorphology, conventional and multiplex IHC, and RNA expression analysis. The data revealed no regional differences in the number of tumor-infiltrating lymphocytes (TIL) in the 1,237 SSA breast cancer samples, while the distribution of TILs in different breast cancer IHC subtypes showed regional diversity, particularly when compared with German samples. Higher TIL densities were associated with better survival in the SSA cohort (n = 400), but regional differences concerning the predictive value of TILs existed. High numbers of CD163+ macrophages and CD3+CD8+ T cells accompanied by reduced cytotoxicity, altered IL10 and IFNγ levels and downregulation of MHC class I components were predominantly detected in breast cancer samples from Western SSA. Features of nonimmunogenic breast cancer phenotypes were associated with reduced patient survival (n = 131). We therefore conclude that regional diversity in the distribution of breast cancer subtypes, TME composition, and immune escape mechanisms should be considered for therapy decisions in SSA and the design of personalized therapies. See related Spotlight by Bergin et al., p. 705.

Abstract 3508: Association between clonal hematopoiesis and risk of prostate cancer in a large sample of African ancestry men

Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with inflammation, which is a risk factor for cancer, including prostate cancer. We previously reported weak evidence of an association between CHIP and prostate cancer risk in men of European ancestry. However, little is known for African ancestry populations. We investigated the association of age-related CHIP with overall and aggressive prostate cancer risk in a large whole-exome sequencing study of 12,049 African ancestry men, including 7,176 prostate cancer cases (of which 3,283 had aggressive disease and 1,074 had metastatic disease) and 4,873 controls. Somatic variant calling was carried out using GATK Mutect2, and only variants with minor allele frequencies (MAF) &lt;0.1% and a variant allelic fraction (VAF) &gt;5% were included. Variants with a MAF ≥0.1% in gnomAD were excluded. CHIP variants were identified from a list of pre-specified mutations in 74 genes. Associations were tested using regression models adjusting for age, sub-study, and top 10 principal components, with statistical significance tested by the likelihood ratio test and applying a Bonferroni correction to account for multiple testing. In total, 998 variants in 57 CHIP genes were identified. Consistent with previous results, we observed a strong association between CHIP and age at blood draw. CHIP genes in aggregate were not statistically significantly associated with risks of total (OR=1.12, 95% CI=0.97-1.28), aggressive (OR=1.14, 95% CI=0.92-1.43) or metastatic (OR=1.17, 95% CI=0.91-1.49) prostate cancer. We observed that carriers of variants in DNMT3A, which is the gene that harbors the most CHIP driver mutations, had a nominally elevated risk of prostate cancer compared to non-carriers (OR=1.35, 95% CI=1.08-1.68, p=0.007). Additionally, carriers of variants in EZH2, which is implicated in cancer progression, showed a suggestive association with aggressive prostate cancer (OR=7.33, 95% CI=1.01-53.21, p=0.029). After adjusting for age at blood draw, CHIP genes in aggregate were not associated with age at prostate cancer diagnosis. However, we found that EZH2 variants carriers were diagnosed 12.9 years earlier on average than non-carriers (95% CI=6.1-19.7, adjusted p=0.01). A prostate cancer polygenic risk score (PRS) constructed using 269 risk variants was not associated with CHIP carrier status in aggregate (OR=0.99, 95% CI=0.92-1.06, p=0.70) or with any individual gene (all adjusted p&gt;0.05). In summary, overall CHIP is not likely to be a risk factor of prostate cancer or aggressive disease in men of African ancestry. However, our results do confirm the association of CHIP in DNMT3A with prostate cancer risk as reported in previous studies in men of European ancestry. Future work will be needed to evaluate the biological causality of DNMT3A- and EZH2- related CHIP on prostate cancer.

Citation Format: Anqi Wang, Yili Xu, Xin Sheng, Raymond Hughley, Ben Adusei, Mohamed Jalloh, Serigne Magueye Gueye, Andrew A Adjei, James Mensah, Pedro W. Fernandez, Akin Olupelumi Adebiyi, Oseremen Inokhoife Aisuodionoe-Shadrach, Lindsay Petersen, Maureen Joffe, Jeannette T. Bensen, James L. Mohler, Jack A. Taylor, Eboneé N. Butler, Sue A. Ingles, Benjamin A. Rybicki, Janet L. Stanford, Wei Zheng, Sonja I. Berndt, Chad D. Huff, Joseph Lachance, Luc Multigner, Caroline Andrews, Timothy R. Rebbeck, Laurent Brureau, Stephen J. Chanock, Adam de Smith, Fei Chen, Burcu F. Darst, David V. Conti, Christopher A. Haiman. Association between clonal hematopoiesis and risk of prostate cancer in a large sample of African ancestry men [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3508.

Discordance between PAM50 intrinsic subtyping and immunohistochemistry in South African women with breast cancer

PURPOSE

Breast cancer is a heterogeneous disease with different gene expression profiles, treatment options and outcomes. In South Africa, tumors are classified using immunohistochemistry. In high-income countries multiparameter genomic assays are being utilized with implications for tumor classification and treatment.

METHODS

In a cohort of 378 breast cancer patients from the SABCHO study, we investigated the concordance between tumor samples classified by IHC and the PAM50 gene assay.

RESULTS

IHC classified patients as ER-positive (77.5%), PR-positive (70.6%), and HER2-positive (32.3%). These results, together with Ki67, were used as surrogates for intrinsic subtyping, and showed 6.9% IHC-A-clinical, 72.7% IHC-B-clinical, 5.3% IHC-HER2-clinical and 15.1% triple negative cancer (TNC). Typing using the PAM50 gave 19.3% luminal-A, 32.5% luminal-B, 23.5% HER2-enriched and 24.6% basal-like. The basal-like and TNC had the highest concordance, while the luminal-A and IHC-A group had the lowest concordance. By altering the cutoff for Ki67, and realigning the HER2/ER/PR-positive patients to IHC-HER2, we improved concordance with the intrinsic subtypes.

CONCLUSION

We suggest that the Ki67 be changed to a cutoff of 20-25% in our population to better reflect the luminal subtype classifications. This change would inform treatment options for breast cancer patients in settings where genomic assays are unaffordable.

Abstract P1-01-03: The Impact of Comorbid HIV infection on Neoadjuvant and Adjuvant Chemotherapy Relative Dose Intensity in South African Breast Cancer Patients

Introduction In the South African Breast Cancer and HIV Outcomes (SABCHO) study, early-stage breast cancer patients living with HIV, compared to their HIV-negative counterparts, demonstrated higher overall mortality and lower rates of pathologic complete response if treated with neoadjuvant chemotherapy. We aimed to determine if comorbid HIV also impacted receipt of timely and complete neoadjuvant and adjuvant chemotherapy. Methods We retrospectively identified Black, stage I-III SABCHO participants diagnosed with breast cancer from June 2015 to July 2019 and who received at least 2 doses of neoadjuvant or adjuvant chemotherapy at either Charlotte Maxeke Johannesburg Academic Hospital (Gauteng) or Grey’s Hospital (KwaZulu-Natal). Data on the originally prescribed chemotherapy regimen and the dose and timing of all received chemotherapy was extracted from patients’ medical records, as well as values from all complete blood counts and metabolic panels performed during treatment. Relative dose intensity (RDI) was calculated for each agent in the prescribed regimen with the mean RDI of all agents representing the RDI of the full regimen. We assessed for associations between full regimen RDI and HIV status using a multivariable linear regression model that included demographic and clinical covariates also shown to impact RDI. We also compared rates of myelosuppression, alkaline phosphatase elevation, and creatinine elevation using linear regression. Using previously collected survival data, we compared overall mortality based on overall RDI above or below 0.85. Results We analyzed data from 325 eligible subjects, 166 of whom were living with HIV. No differences based on HIV status were appreciated in the prescribed chemotherapy regimens. For women without HIV median RDI was 0.87 (interquartile range (IQR) 0.77-0.94) and, in those living with HIV, it was 0.89 (IQR 0.77-0.95). HIV status showed no significant association with RDI on multivariable analysis, and the only patient characteristics associated with RDI were estrogen/progesterone receptor (ER/PR) and HER2 status. Patients living with HIV experienced more CTCAE v5.0 grade 3+ anemia and leukopenia than those without HIV (anemia: 10.8% vs 1.9%, p=0.001; leukopenia: 8.4% vs 1.9%, p=0.008) and were more likely to receive at least one dose of filgrastim (24.7% vs 10.7%, p=0.001). Receipt of RDI greater or less than 0.85 did not predict overall mortality in the full cohort or HIV status subgroups. A trend towards improved survival with RDI greater than 0.85 was seen among the 69 participants with ER/PR negative disease (hazard ratio: 0.60, 95% confidence interval: 0.30-1.21, p = 0.15). Conclusions Neoadjuvant and adjuvant chemotherapy RDI did not differ by HIV status among women in the SABCHO study, although women living with HIV experienced more myelotoxicity during treatment. Efforts to reduce chemotherapy dose reduction and delays should target all South African breast cancer patients.

Citation Format: Daniel S. O’Neil, Oluwatosin A Ayeni, Hayley A. Farrow Woolridge, Wenlong Carl Chen, Georgia Demetriou, Ines Buccimazza, Sharon Cacala, Maureen Joffe, Michael Antoni, Gilberto Lopes, Yoanna Pumpalova, Witness Mapanga, Judith S. Jacobson, Katherine D. Crew, Alfred I. Neugut, Paul Ruff, Herbert Cubasch. The Impact of Comorbid HIV infection on Neoadjuvant and Adjuvant Chemotherapy Relative Dose Intensity in South African Breast Cancer Patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-01-03.

Abstract P4-07-03: The impact of HIV on non-adherence for tamoxifen among women with breast cancer in South Africa

Introduction HIV-positive women with breast cancer (BC) have worse overall survival than HIV-negative women with BC, and poor adherence to prescribed tamoxifen is known to contribute to poor survival. We, therefore, investigated the association of HIV infection with adherence to adjuvant tamoxifen among women with localized hormone receptor (HR)-positive breast cancer in South Africa. Methods Among 4,097 women diagnosed with breast cancer at six hospitals in the prospective South African Breast Cancer and HIV Outcomes (SABCHO) cohort study between July 2015 and December 2020, we focused on women with stages I-III HR-positive breast cancer who were prescribed 20mg of adjuvant tamoxifen daily for ≥3 months during the study period. We collected venous blood once from each participant during a routine clinic visit and analyzed concentrations of tamoxifen and its metabolites using a triple quadruple mass spectrometer. We defined non-adherence as a tamoxifen level &lt; 60ng/mL after 3 months of prescribed daily tamoxifen use. We compared socio-demographic, lifestyle factors, tamoxifen-related side effects, and concurrent medication use among women with and without HIV and developed multivariable logistic regression models of tamoxifen non-adherence. Results Among 369 participants, 78 (21.1%) were HIV-positive and 291 (78.9%) HIV-negative. After a median (interquartile range) time of 13.0 (6.2-25.2) months since tamoxifen initiation, the tamoxifen serum concentration ranged between 1.54 and 943.0ng/mL, with a median of 52.3ng/mL. In the full cohort, 208 women (56.4%) were non-adherent to tamoxifen; only 161 (43.6%) were adherent. Women &lt; 40 years of age were less likely to adhere to tamoxifen than women &gt;60 years (73.4% vs 52.6%, odds ratio (OR)=2.49, 95% confidence interval (CI)=1.26-4.94); likewise, HIV-positive women (70.5% vs 52.6%, OR=2.16, 95% CI=1.26-3.70) were less likely to adhere than HIV-negative women. In an adjusted model, only HIV was associated with non-adherence; HIV-positive women had twice the odds of non-adherence to tamoxifen, compared to HIV-negative women (OR=2.40, 95% CI=1.11-5.20). Conclusion Non-adherence to tamoxifen may limit the overall survival of women with HR-positive breast cancer; in our study, especially in HIV-positive women.

Citation Format: Oluwatosin A Ayeni, Shingirai Chiwambutsa, Wenlong Carl Chen, Nyasha N. Kapungu, Comfort Kanji, Roslyn Thelingwani, Nivashni Murugan, Rophiwa Mathiba, Boitumelo Phakathi, Sarah Nietz, Duvern Ramiah, Daniel S. O’Neil, Judith S. Jacobson, Paul Ruff, Herbert Cubasch, Tobias Chirwa, Maureen Joffe, Collen Masimirembwa, Alfred I. Neugut. The impact of HIV on non-adherence for tamoxifen among women with breast cancer in South Africa [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-03.

Drivers of disparities in stage at diagnosis among women with breast cancer: South African breast cancers and HIV outcomes cohort

OBJECTIVE

In low- and middle-income countries (LMICs), advanced-stage diagnosis of breast cancer (BC) is common, and this contributes to poor survival. Understanding the determinants of the stage at diagnosis will aid in designing interventions to downstage disease and improve survival from BC in LMICs.

METHODS

Within the South African Breast Cancers and HIV Outcomes (SABCHO) cohort, we examined factors affecting the stage at diagnosis of histologically confirmed invasive breast cancer at five tertiary hospitals in South Africa (SA). The stage was assessed clinically. To examine the associations of the modifiable health system, socio-economic/household and non-modifiable individual factors, hierarchical multivariable logistic regression with odds of late-stage at diagnosis (stage III-IV), was used.

RESULTS

The majority (59%) of the included 3497 women were diagnosed with late-stage BC disease. The effect of health system-level factors on late-stage BC diagnosis was consistent and significant even when adjusted for both socio-economic- and individual-level factors. Women diagnosed in a tertiary hospital that predominantly serves a rural population were 3 times (OR = 2.89 (95% CI: 1.40-5.97) as likely to be associated with late-stage BC diagnosis when compared to those diagnosed at a hospital that predominantly serves an urban population. Taking more than 3 months from identifying the BC problem to the first health system entry (OR = 1.66 (95% CI: 1.38-2.00)), and having luminal B (OR = 1.49 (95% CI: 1.19-1.87)) or HER2-enriched (OR = 1.64 (95% CI: 1.16-2.32)) molecular subtype as compared to luminal A, were associated with a late-stage diagnosis. Whilst having a higher socio-economic level (a wealth index of 5) reduced the probability of late-stage BC at diagnosis, (OR = 0.64 (95% CI: 0.47-0.85)).

CONCLUSION

Advanced-stage diagnosis of BC among women in SA who access health services through the public health system was associated with both modifiable health system-level factors and non-modifiable individual-level factors. These may be considered as elements in interventions to reduce the time to diagnosis of breast cancer in women.

The impact of HIV on non-adherence for tamoxifen among women with breast cancer in South Africa

PURPOSE

Women living with HIV (WLWH) and breast cancer (BC) have worse overall survival than HIV-negative women with BC, and poor adherence to prescribed tamoxifen is known to contribute to poor survival. We therefore investigated the association of HIV infection with adherence to adjuvant tamoxifen among women with localized hormone receptor (HR)-positive breast cancer in South Africa.

METHODS

Among 4,097 women diagnosed with breast cancer at six hospitals in the prospective South African Breast Cancer and HIV Outcomes (SABCHO) cohort study between July 2015 and December 2020, we focused on black women with stages I-III HR-positive breast cancer who were prescribed 20 mg of adjuvant tamoxifen daily. We collected venous blood once from each participant during a routine clinic visit, and analyzed concentrations of tamoxifen and its metabolites using a triple quadruple mass spectrometer. We defined non-adherence as a tamoxifen level < 60 ng/mL after 3 months of daily tamoxifen use. We compared tamoxifen-related side effects, and concurrent medication use among women with and without HIV and developed multivariable logistic regression models of tamoxifen non-adherence.

RESULTS

Among 369 subjects, 78 (21.1%) were WLWH and 291 (78.9%) were HIV-negative. After a median (interquartile range) time of 13.0 (6.2-25.2) months since tamoxifen initiation, the tamoxifen serum concentration ranged between 1.54 and 943.0 ng/mL and 208 (56.4%) women were non-adherent to tamoxifen. Women < 40 years of age were more likely to be non-adherent than women > 60 years (73.4% vs 52.6%, odds ratio (OR) = 2.49, 95% confidence interval (CI) = 1.26-4.94); likewise, WLWH (70.5% vs 52.6%, OR = 2.16, 95% CI = 1.26-3.70) than HIV-negative women. In an adjusted model WLWH had twice the odds of non-adherence to tamoxifen, compared to HIV-negative women (OR = 2.40, 95% CI = 1.11-5.20).

CONCLUSION

High rates of non-adherence to adjuvant tamoxifen may limit the overall survival of black South African women with HR-positive breast cancer, especially among WLWH.

Multimorbidity and overall survival among women with breast cancer: results from the South African Breast Cancer and HIV Outcomes Study

BACKGROUND

Breast cancer survival in South Africa is low, but when diagnosed with breast cancer, many women in South Africa also have other chronic conditions. We investigated the impact of multimorbidity (≥ 2 other chronic conditions) on overall survival among women with breast cancer in South Africa.

METHODS

Between 1 July 2015 and 31 December 2019, we enrolled women newly diagnosed with breast cancer at six public hospitals participating in the South African Breast Cancer and HIV Outcomes (SABCHO) Study. We examined seven chronic conditions (obesity, hypertension, diabetes, HIV, cerebrovascular diseases (CVD), asthma/chronic obstructive pulmonary disease, and tuberculosis), and we compared socio-demographic, clinical, and treatment factors between patients with and without each condition, and with and without multimorbidity. We investigated the association of multimorbidity with overall survival using multivariable Cox proportional hazard models.

RESULTS

Of 3,261 women included in the analysis, 45% had multimorbidity; obesity (53%), hypertension (41%), HIV (22%), and diabetes (13%) were the most common individual conditions. Women with multimorbidity had poorer overall survival at 3 years than women without multimorbidity in both the full cohort (60.8% vs. 64.3%, p = 0.036) and stage groups: stages I-II, 80.7% vs. 86.3% (p = 0.005), and stage III, 53.0% vs. 59.4% (p = 0.024). In an adjusted model, women with diabetes (hazard ratio (HR) = 1.20, 95% confidence interval (CI) = 1.03-1.41), CVD (HR = 1.43, 95% CI = 1.17-1.76), HIV (HR = 1.21, 95% CI = 1.06-1.38), obesity + HIV (HR = 1.24 95% CI = 1.04-1.48), and multimorbidity (HR = 1.26, 95% CI = 1.13-1.40) had poorer overall survival than women without these conditions.

CONCLUSIONS

Irrespective of the stage, multimorbidity at breast cancer diagnosis was an important prognostic factor for survival in our SABCHO cohort. The high prevalence of multimorbidity in our cohort calls for more comprehensive care to improve outcomes for South African women with breast cancer.

A qualitative study to explore healthcare providers' perspectives on barriers and enablers to early detection of breast and cervical cancers among women attending primary healthcare clinics in Johannesburg, South Africa

Low-and-middle income countries (LMICs) contribute approximately 70% of global cancer deaths, and the cancer incidence in these countries is rapidly increasing. Sub-Saharan African (SSA) countries, including South Africa (SA), bear some of the world's highest cancer case fatality rates, largely attributed to late diagnosis. We explored contextual enablers and barriers for early detection of breast and cervical cancers according to facility managers and clinical staff at primary healthcare clinics in the Soweto neighbourhood of Johannesburg, South Africa. We conducted qualitative in-depth interviews (IDIs) between August and November 2021 amongst 13 healthcare provider nurses and doctors as well as 9 facility managers at eight public healthcare clinics in Johannesburg. IDIs were audio-recorded, transcribed verbatim, and entered into NVIVO for framework data analysis. Analysis was stratified by healthcare provider role and identified apriori around the themes of barriers and facilitators for early detection and management of breast and cervical cancers. Findings were conceptualised within the socioecological model and then explored within the capability, opportunity and motivation model of behaviour (COM-B) for pathways that potentially influence the low screening provision and uptake. The findings revealed provider perceptions of insufficient South African Department of Health (SA DOH) training support and staff rotations resulting in providers lacking knowledge and skills on cancer, screening policies and techniques. This coupled with provider perceptions of poor patient cancer and screening knowledge revealed low capacity for cancer screening. Providers also perceived opportunity for cancer screening to be undermined by the limited screening services mandated by the SA DOH, insufficient providers, inadequate facilities, supplies and barriers to accessing laboratory results. Providers perceived women to prefer to self-medicate and consult with traditional healers and access primary care for curative services only. These findings compound the low opportunity to provide and demand cancer screening services. And because the National SA Health Department is perceived by providers not to prioritize cancer nor involve primary care stakeholders in policy and performance indicator development, overworked, unwelcoming providers have little motivation to learn screening skills and provide screening services. Providers reported that patients preferred to go elsewhere and that women perceived cervical cancer screening as painful. These perceptions must be confirmed for veracity among policy and patient stakeholders. Nevertheless, cost-effective interventions can be implemented to address these perceived barriers including multistakeholder education, mobile and tent screening facilities and using existing community fieldworkers and NGO partners in providing screening services. Our results revealed provider perspectives of complex barriers to the early detection and management of breast and cervical cancers in primary health clinic settings in Greater Soweto. These barriers together appear potentially to produce compounding effects, and therefore there is a need to research the cumulative impact but also engage with stakeholder groups to verify findings and create awareness. Additionally, opportunities do exist to intervene across the cancer care continuum in South Africa to address these barriers by improving the quality and volume of provider cancer screening services, and in turn, increasing the community demand and uptake for these services.

Degree of food processing and breast cancer risk in black urban women from Soweto, South African: the South African Breast Cancer study

This study aimed to investigate the association between consumption of ultra-processed foods, whole foods and breast cancer risk in black women from Soweto, South Africa. A population-based case (n 396)-control (n 396) study matched on age and residence, using data from the South African Breast Cancer study. Dietary intake was assessed using a validated quantified FFQ. Food items were categorised using the NOVA system ((1) unprocessed/minimally processed foods, (2) culinary ingredients, (3) processed foods and (4) ultra-processed foods). Conditional logistic regression models were used to estimate OR and 95 % CI of dietary contributions from each NOVA food group (as a percentage of total energy intake (EI)) and adjusting for potential confounders. Considering contributions to total EI per day, ultra-processed food consumption contributed to 44·8 % in cases and 47·9 % in controls, while unprocessed/minimally processed foods contributed to 38·8 % in cases and 35·2 % in controls. Unprocessed/minimally processed food consumption showed an inverse association with breast cancer risk overall (OR = 0·52, 95 % CI 0·35, 0·78), as well as in pre- and postmenopausal women separately (OR = 0·52, 95 % CI 0·27, 0·95 and OR = 0·55, 95 % CI 0·35, 0·89, respectively) and in women with progesterone positive breast cancer (OR = 0·23, 95 % CI 0·06, 0·86). There was no heterogeneity in association with breast cancer when analyses were stratified according to BMI. No significant associations were observed for the consumption of other NOVA food groups. Intake of unprocessed/minimally processed foods may reduce the risk of developing breast cancer in black women from Soweto, South Africa.

The effect of medical castration on lipid levels in black South African men with prostate cancer

Background

In South Africa, androgen deprivation therapy (ADT) is commonly given as primary therapy for prostate cancer (PCa) due to many patients presenting with advanced disease. The metabolic adverse effects of ADT on lipid profile and weight gain have been reported mainly in Caucasian populations, but few studies have been performed in African populations. Men of African descent generally have favorable lipid profiles compared to other populations, and our study looked to analyze the effect of medical castration on lipid levels in black South African men with PCa.

Methods

The aim of this study is to describe the changes in blood total cholesterol, triglycerides, LDL and HDL at 6 months and at 1 year in men with prostate cancer newly initiated on ADT. Changes to BMI, waist circumference and HbA1c were also measured after 1 year of ADT.

Our study was conducted at Chris Hani Baragwanath Academic Hospital which is a teaching hospital affiliated with the University of the Witwatersrand. It is located in Soweto, South of Johannesburg, and serves the 1.3 million local residents who are predominantly black and of the lower-income bracket. This study enrolled 38 black South African men who were starting to receive ADT for PCa. Subjects were evaluated at baseline and at 6 and 12 months. Lipid profiles and HbA1C levels were measured using blood samples, and body composition was measured using BMI and waist circumference.

Results

In this prospective single-center study, we found that ADT resulted in a significant rise in triglyceride levels and weight gain in black South African men reaching mean levels of obesity using ethnic-specific definitions. High-density lipoproteins levels decreased significantly particularly in the first 6 months of treatment and thereafter began to rise. ADT also resulted in an increased HbA1C level which is a marker for insulin resistance.

Conclusions

Androgen deprivation therapy unfavorably changed the body habitus and lipid profile of men with PCa. It was demonstrated that even black South Africans who generally have favorable lipid profiles compared to their counterparts are at risk of developing metabolic syndrome while being treated with ADT.

Prevalence of multimorbidity in men of African descent with and without prostate cancer in Soweto, South Africa

OBJECTIVE

With increases in chronic disease, men with prostate cancer are likely to have at least one other chronic health condition. The burden and complexity of each additional chronic disease may complicate prostate cancer treatment and reduce survival. In this paper, we describe the frequency of multimorbid chronic diseases, HIV and depression among men in Soweto, South Africa (SA) with and without prostate cancer and determine whether the presence of multimorbid diseases is associated with metastatic and high-risk, non-metastatic prostate cancer.

METHODS

A population-based case-control study on prostate cancer was conducted among black men in Soweto. All participants completed a baseline survey on sociodemographics, lifestyle, and comorbid medical conditions. All participants completed a depression screening survey and HIV testing at enrolment. Blood pressure measurements and blood testing for fasting glucose, total cholesterol, and high-density lipoprotein were performed on a subset of randomly selected cases and controls. For men with prostate cancer, clinical T staging was assessed with the digital rectal examination, the diagnosis was confirmed with a biopsy and PSA levels were assessed at presentation. The metastatic staging was assessed by bone scans, and this was confirmed with PSMA PET scans, CT scans and X-rays, standard for our resource-constrained setting. Normal PSA scores were used as an inclusion criterion for controls.

RESULTS

Of the 2136 men (1095 with prostate cancer and 1041 controls) included in the analysis, 43.0% reported at least one chronic metabolic disease; 24.1% reported two metabolic diseases; 5.3% reported three metabolic diseases; and 0.3% reported four metabolic diseases. Men with prostate cancer were more likely to report a multimorbid chronic metabolic disease compared to controls (p<0.001) and more likely to test positive for HIV (p = 0.05). The majority of men (66.2%) reported at least one metabolic disease, tested negative for HIV and had a negative depression screen. The clinical characteristics of men with prostate cancer, were as follows: 396 (36.2%) had a Gleason score of 8 and above; 552 (51.3%) had a PSA score of >20ng/ml; 233 (21.7%) had confirmed metastatic prostate cancer at diagnosis. Older age was associated with metastatic prostate cancer (OR = 1.043 95% CI:1.02-1.07) and NCCN defined high-risk non-metastatic prostate cancer (OR = 1.03 95% CI:1.01-1.05), whilst being hypertensive was protective (OR = 0.63 95% CI:0.47-0.84 and OR = 0.55 95% CI:0.37-0.83) respectively for metastatic and high-risk, non-metastatic prostate cancer.

CONCLUSION

The high prevalence of multimorbid metabolic diseases and HIV among men with prostate cancer represents a public health concern in South Africa. There is a need to effectively address multiple chronic diseases among men with prostate cancer by incorporating coordinated care models.

Prevalence of monoclonal gammopathy of undetermined significance in Black South African men

BACKGROUND

Both multiple myeloma and its precursor, monoclonal gammopathy of undetermined significance (MGUS), occur twice as often within Black compared to White populations, suggesting that racial disparities lie within the development of MGUS. Nonetheless, MGUS has been studied mainly in White cohorts; the study that first described the natural history of MGUS was conducted in 97.3% White Olmsted County, Minnesota.

METHODS

We determined the prevalence of MGUS among 386 Black South African (SA) men >30 years at Chris Hani Baragwanath Hospital in Johannesburg. We conducted serum protein electrophoresis and free light chain quantification to define MGUS by the same criteria as the Olmsted County studies. We also investigated the association between MGUS and various clinical factors, including HIV infection and smoking.

RESULTS

We found the prevalence of MGUS to be 8.03% (95%CI 5.32-10.74), nearly 1.6-fold higher than in the White Olmsted County male population. In a univariable logistic regression model, MGUS was associated with HIV status (Odds Ratio, OR 2.39, 95%CI 0.95-5.49), but in an adjusted model that included body mass index and cigarette use, the association was not statistically significant. Those who were current (vs. never) cigarette smokers were more likely to have MGUS in both univariable (OR 5.60, 95%CI 2.16-17.42) and multivariable models (OR 4.49, 95%CI 1.63-14.56).

CONCLUSIONS

The prevalence of MGUS in Black SA men is substantially higher than in White populations and may be associated with HIV status and cigarette use.

IMPACT

Racial disparities in MGUS exist and may be associated with potentially modifiable risk factors.

Testing the generalizability of ancestry-specific polygenic risk scores to predict prostate cancer in sub-Saharan Africa

BACKGROUND

Genome-wide association studies do not always replicate well across populations, limiting the generalizability of polygenic risk scores (PRS). Despite higher incidence and mortality rates of prostate cancer in men of African descent, much of what is known about cancer genetics comes from populations of European descent. To understand how well genetic predictions perform in different populations, we evaluated test characteristics of PRS from three previous studies using data from the UK Biobank and a novel dataset of 1298 prostate cancer cases and 1333 controls from Ghana, Nigeria, Senegal, and South Africa.

RESULTS

Allele frequency differences cause predicted risks of prostate cancer to vary across populations. However, natural selection is not the primary driver of these differences. Comparing continental datasets, we find that polygenic predictions of case vs. control status are more effective for European individuals (AUC 0.608-0.707, OR 2.37-5.71) than for African individuals (AUC 0.502-0.585, OR 0.95-2.01). Furthermore, PRS that leverage information from African Americans yield modest AUC and odds ratio improvements for sub-Saharan African individuals. These improvements were larger for West Africans than for South Africans. Finally, we find that existing PRS are largely unable to predict whether African individuals develop aggressive forms of prostate cancer, as specified by higher tumor stages or Gleason scores.

CONCLUSIONS

Genetic predictions of prostate cancer perform poorly if the study sample does not match the ancestry of the original GWAS. PRS built from European GWAS may be inadequate for application in non-European populations and perpetuate existing health disparities.

Impact of HIV infection on survival among women with stage I-III breast cancer: Results from the South African breast cancer and HIV outcomes study

In some countries of sub-Saharan Africa, the prevalence of HIV exceeds 20%; in South Africa, 20.4% of people are living with HIV. We examined the impact of HIV infection on the overall survival (OS) of women with nonmetastatic breast cancer (BC) enrolled in the South African Breast Cancer and HIV Outcomes (SABCHO) study. We recruited women with newly diagnosed BC at six public hospitals from 1 July 2015 to 30 June 2019. Among women with stages I-III BC, we compared those with and without HIV infection on sociodemographic, clinical, and treatment factors. We analyzed the impact of HIV on OS using multivariable Cox proportional hazard models. Of 2367 women with stages I-III BC, 499 (21.1%) had HIV and 1868 (78.9%) did not. With a median follow-up of 29 months, 2-year OS was poorer among women living with HIV (WLWH) than among HIV-uninfected women (72.4% vs 80.1%, P < .001; adjusted hazard ratio (aHR) 1.49, 95% confidence interval (CI) = 1.22-1.83). This finding was consistent across age groups ≥45 years and <45 years, stage I-II BC and stage III BC, and ER/PR status (all P < .03). Both WLWH with <50 viral load copies/mL and WLWH with ≥50 viral load copies/mL had poorer survival than HIV-uninfected BC patients [aHR: 1.35 (1.09-1.66) and 1.54 (1.20-2.00), respectively], as did WLWH who had ≥200 CD4+ cells/mL at diagnosis [aHR: 1.39 (1.15-1.67)]. Because receipt of antiretroviral therapy has become widespread, WLWH is surviving long enough to develop BC; more research is needed on the causes of their poor survival.

Predictors of overall survival among Black South African men treated with androgen-deprivation therapy for metastatic prostate cancer

5046

Background: Men in sub-Saharan Africa (SSA) are disproportionately affected by prostate cancer (PCa), and many have metastatic disease (mPCA) at presentation. In SSA, androgen deprivation therapy (ADT) is the first-line treatment for mPCa, and often the only available therapy. Treatment failure and death is common. We identified predictors of overall survival (OS) in Black South African (SA) men with mPCa on ADT. Methods: We performed a retrospective analysis of prospectively gathered data from men diagnosed with mPCA (3/22/2016 - 10/30/2020) at Chris Hani Baragwanath Hospital in Johannesburg, which was also a study site for the concurrent Men of African Descent and Carcinoma of the Prostate study. We included men with mPCA treated with ADT (received at least 1 dose of luteinizing hormone-releasing hormone agonist and/or had surgical castration), who had ≥1 PSA level drawn ≥12 weeks after ADT start. OS was defined from ADT start to death. PSA progression (PSA-P) definition was adapted from PCWG 3. Cox regression models were used to identify predictors of OS. PSA-P was treated as a time-dependent covariate. Results: Of 200 men with mPCa, we excluded 6 who did not receive ADT and 41 without sufficient data for PSA-P analysis. Of 153 men, 26.8% were <65 years old and 12% had a family history of PCa. Median PSA at diagnosis was 71.5 ng/mL (interquartile range (IQR) 20.7-432.6), median alkaline phosphatase level (ALP) 108 IU/L (79-224) and median hemoglobin (Hb) 13 g/dL (IQR 10-15). Median PSA nadir was 2.8 ng/mL (IQR 0.55-17.93). The rate of PSA-P at 1- and 2-years was 12.1% [95%CI 5.9-17.8] and 37.5% [95%CI 26.1-47.2]. The median follow-up was 2.75 years, and the 3-year OS was 61.9% [95%CI 52.7-72.6]. Cox proportional hazard ratio (HR) models of risk factors for OS are shown in Table 1. PSA-P was a strong predictor of OS. Men with PSA nadir >4ng/mL after ADT start had a HR for death of 3.77 [1.86-7.62]. Men with ALP >150 IU/L and those with Hb <13.5g/dL at diagnosis were also at higher risk for death (HR 3.09 [1.64-5.83] and HR 2.00 [1.28-6.56] respectively). Conclusions: Among Black men in SA treated with ADT for mPCA, PSA-P strongly predicts OS. In this cohort, high ALP and anemia at diagnosis, and PSA nadir >4ng/mL after ADT start are associated with higher risk for death. These factors can be used identify high risk men with mPCA, for whom early treatment escalation to chemotherapy should be considered. [Table: see text]

Treatment guideline concordance, initiation, and abandonment in patients with non-metastatic breast cancer from the African Breast Cancer-Disparities in Outcomes (ABC-DO) cohort in sub-Saharan Africa: a prospective cohort study

BACKGROUND

Comprehensive breast cancer management is essential to achieve high breast cancer survival; however, detailed reports of the treatment regimens received by patients are scarce in sub-Saharan Africa where survival is low. We aimed to examine treatment initiation, guideline concordance, and abandonment in patients with non-metastatic breast cancer in sub-Saharan Africa from the African Breast Cancer-Disparities in Outcomes (ABC-DO) prospective cohort.

METHODS

The ABC-DO prospective cohort study recruited women (aged ≥18 years) with newly diagnosed invasive breast cancer in eight hospitals across five sub-Saharan African countries (Namibia, Nigeria, Uganda, South Africa, and Zambia). We analysed treatments received by women who were classified as non-metastatic (M0) at the initial presentation. Data on surgery, radiotherapy, and systemic therapies were obtained from medical records and a self-reported follow-up questionnaire at 6 months after the diagnosis, follow-up calls every 3 months, and a baseline questionnaire. Initiation, completion, and abandonment of treatment modalities and combined therapy regimens were examined overall, by country-specific groups, and by clinical factors relevant for guideline-based treatment.

FINDINGS

Of 2313 women recruited into the ABC-DO study between Sept 10, 2014, and Dec 31, 2017, 2226 had histologically or clinically confirmed breast cancer. Of these 2226 women, 510 were excluded from the present analysis because 378 had metastatic disease, 37 were prevalent cases (defined as those previously diagnosed with breast cancer >2 years before baseline), 82 had unknown TNM stage, and 13 were White or Asian women in South Africa (number was too small for analysis). After a median follow-up of 5·2 years (IQR 4·6-5·9), 1163 (68%) of 1716 women underwent breast cancer surgery. Surgery and systemic therapy (ie, multimodality treatment) with radiotherapy was initiated in 370 (36%) of 1028 women with localised tumours versus 156 (23%) of 688 women with locally advanced tumours, whereas multimodality treatment without radiotherapy was initiated in 386 (38%) versus 167 (24%) women, respectively. Of 1530 patients requiring chemotherapy (which excludes 105 who died within 6 months after baseline), 1013 (66%) initiated treatment of neoadjuvant chemotherapy or surgery within 3 months after baseline, which was adequately completed by 359 (35%) of 1013 women, marginally completed by 284 (28%), abandoned by 200 (20%), and unknown in 151 (15%). 19 (2%) women died within 6 months after chemotherapy initiation. Of 1375 women in whom endocrine therapy was indicated, this treatment was initiated in 920, and lasted at least 3 years in 367 (40%) women. Treatment disparities between country-specific groups were substantial for all therapy regimens.

INTERPRETATION

A high proportion of patients with non-metastatic breast cancer did not initiate, did not fully complete, or abandoned treatment with surgery, systemic therapy, radiotherapy, or an appropriate combination of these, highlighting the need for improved treatment access and completion in sub-Saharan Africa to potentially prevent premature breast cancer deaths.

FUNDING

National Institutes of Health (National Cancer Institute), Susan G Komen, and the International Agency for Research on Cancer.

Prevalence of monoclonal gammopathy of undetermined significance in black South African men

e20032

Background: Monoclonal gammopathy of undetermined significance (MGUS) is the precursor to multiple myeloma (MM). MM disproportionately affects black individuals, but the cumulative risk of progression from MGUS to malignancy does not differ by race. Hence, the racial disparities in MM incidence appear to arise from differences in the occurrence of MGUS. Nonetheless, MGUS has been studied mainly in white populations; the study that first described the natural history of MGUS was conducted by Kyle, et al. (2006) in 97.3% white Olmsted County, Minnesota. Methods: We determined the prevalence of MGUS among black South African men >30 years of age at the Chris Hani Baragwanath Academic Hospital in Johannesburg. We conducted serum protein electrophoresis (SPEP) and free light chain (FLC) quantification and used the same criteria for MGUS as the Olmsted County studies: a monoclonal protein on SPEP or an abnormal FLC-ratio plus elevation in the appropriate FLC. We also investigated the association between MGUS and various clinical and behavioral factors. Results: The prevalence of MGUS in our cohort (n=386) was 8.03% (95%CI 5.32-10.74), nearly 1.6-fold higher than in Olmsted County males. In a univariable logistic regression model, MGUS was associated with HIV status (odds ratio (OR) 2.39, 95%CI 0.95-5.51), but in the adjusted model that also included body mass index (BMI) and cigarette use, the magnitude of the association decreased to an OR of 2.17 and was not statistically significant. MGUS was associated with current (vs. never) cigarette smoking in both univariable (OR 5.2, 95%CI 1.53-24.0) and multivariable (OR 4.11, 95%CI 1.08-20.4) models. Conclusions: Not only did we find the prevalence of MGUS in black South African men to be substantially higher than in white populations, but we also report that MGUS cases are associated with potentially modifiable risk factors. Building on this pilot study, a larger study is currently underway powered to confirm the relationship between MGUS and HIV, as well as between MGUS and cigarette smoking, in a black African population inclusive of both genders. Future studies designed to evaluate genetic and matched-environmental contributions may elucidate racial disparities and facilitate the development of strategies to prevent plasma cell malignancies.[Table: see text]

Adherence to cancer prevention recommendations is associated with a lower breast cancer risk in black urban South African women

Breast cancer prevention is of great importance to reduce high incidence in South Africa. This study aimed to investigate adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Cancer Prevention Recommendations and the association with breast cancer risk in black urban women from Soweto, South Africa. A total of 396 breast cancer cases and 396 population-based controls from the South African Breast Cancer study (SABC) matched on age and demographic settings were included. Validated questionnaires were used to collect dietary and epidemiological data. To assess adherence to these recommendations, an eight-point adherence score was developed, using tertiles among controls for scoring each recommendation (0, 0·5 and 1) with zero indicating the lowest adherence to the recommendations. OR and 95 % CI were estimated using multivariate logistic regression models to analyse associations between the WCRF/AICR score and breast cancer risk. Greater adherence (>4·5 v. <3·25) to the 2018 WCRF/AICR Cancer Prevention Recommendations was associated with a significant inverse association with breast cancer risk overall (OR = 0·54, 95 % CI 0·35, 0·91) and specifically in postmenopausal women (OR = 0·55, 95 % CI 0·34, 0·95), in cases with oestrogen positive and progesterone positive breast cancer subtypes (OR = 0·54, 95 % CI 0·39, 0·89 and OR = 0·68, 95 % CI 0·43, 0·89, respectively) and in obese women (OR = 0·52, 95 % CI 0·35, 0·81). No significant association with breast cancer risk was observed in premenopausal women. Greater adherence to the 2018 WCRF/AICR Cancer Prevention Recommendations may reduce breast cancer risk in this black urban population of Soweto. Adherence thereof should be encouraged and form a part of cost-effective breast cancer prevention guidelines.

The Impact of Breast Cancer Treatment Delays on Survival Among South African Women

BACKGROUND

In high-income settings, delays from breast cancer (BC) diagnosis to initial treatment worsen overall survival (OS). We examined how time to BC treatment initiation (TTI) impacts OS in South Africa (SA).

METHODS

We evaluated women enrolled in the South African BC and HIV Outcomes study between July 1, 2015 and June 30, 2019, selecting women with stages I-III BC who received surgery and chemotherapy. We constructed a linear regression model estimating the impact of sociodemographic and clinical factors on TTI and separate multivariable Cox proportional hazard models by first treatment (surgery and neoadjuvant chemotherapy (NAC)) assessing the effect of TTI (in 30-day increments) on OS.

RESULTS

Of 1260 women, 45.6% had upfront surgery, 54.4% had NAC, and 19.5% initiated treatment >90 days after BC diagnosis. Compared to the surgery group, more women in the NAC group had stage III BC (34.8% vs 81.5%). Living further away from a hospital and having hormone receptor positive (vs negative) BC was associated with longer TTI (8 additional days per 100 km, P = .003 and 8 additional days, P = .01, respectively), while Ki67 proliferation index >20 and upfront surgery (vs NAC) was associated with shorter TTI (12 and 9 days earlier; P = .0001 and.007, respectively). Treatment initiation also differed among treating hospitals (P < .0001). Additional 30-day treatment delays were associated with worse survival in the surgery group (HR 1.11 [95%CI 1.003-1.22]), but not in the NAC group.

CONCLUSIONS

Delays in BC treatment initiation are common in SA public hospitals and are associated with worse survival among women treated with upfront surgery.

Disparities in breast cancer survival between women with and without HIV across sub-Saharan Africa (ABC-DO): a prospective, cohort study

BACKGROUND

Studies have shown increased mortality among women living with HIV diagnosed with breast cancer compared with HIV-negative women with breast cancer. We aimed to examine how this HIV differential varies by patient or breast tumour characteristics.

METHODS

The African Breast Cancer-Disparities in Outcomes (ABC-DO) study is a prospective cohort of women (aged ≥18 years) with incident breast cancer recruited consecutively at diagnosis (2014-17) from hospitals in Namibia, Nigeria, South Africa, Uganda, and Zambia. Detailed clinical and epidemiological data, including self-reported or tested HIV status, were collected at baseline. Participants were actively followed up via telephone calls every 3 months. The primary outcome was all-cause mortality, assessed in all women who had at least one updated vital status after baseline interview. Using Cox regression, we examined differences in overall survival by HIV status in the cohort, and across country and patient subgroups, adjusted for age, tumour grade, and tumour stage at cancer diagnosis.

FINDINGS

Between Sept 8, 2014, and Dec 31, 2017, we recruited 2154 women with primary breast cancer, 519 of whom were excluded due to their countries having small numbers of women with HIV for comparison. Among the remaining 1635 women, 313 (19%) were living with HIV, 1184 (72%) were HIV negative, and 138 (9%) had unknown HIV status. At breast cancer diagnosis, women with HIV were younger and had lower body-mass index (BMI) than their HIV-negative counterparts, but had similar tumour stage, grade, and receptor subtypes. At the end of the follow-up (Jan 1, 2019), a higher proportion of women with HIV (137 [44%] of 313) had died than had HIV-negative women (432 [37%] of 1184). Crude 3-year survival was 9% lower for women with HIV (46% [95% CI 40-53]) than for HIV-negative women (55% [52-59]; hazard ratio (HR) 1·41 [1·15-1·74]). The HIV survival differential did not differ by age, BMI, tumour subtype, or tumour grade, but was stronger in women with non-metastatic disease (3-year survival 52% HIV-positive vs 63% HIV-negative women, adjusted HR 1·65 [1·30-2·10]), whereas women with metastatic cancer had low survival, regardless of HIV status.

INTERPRETATION

The larger survival deficit among women with HIV with non-metastatic breast cancer calls for a better understanding of the reasons underlying this differential (eg, biological mechanisms, health behaviours, detrimental HIV-breast cancer treatment interactions, or higher HIV background mortality) to inform strategies for reducing mortality among this patient group.

FUNDING

Susan G Komen, International Agency for Research on Cancer, National Cancer Institute, and UK-Commonwealth Scholarships.

Overall and central obesity and prostate cancer risk in African men

PURPOSE

African men are disproportionately affected by prostate cancer (PCa). Given the increasing prevalence of obesity in Africa, and its association with aggressive PCa in other populations, we examined the relationship of overall and central obesity with risks of total and aggressive PCa among African men.

METHODS

Between 2016 and 2020, we recruited 2,200 PCa cases and 1,985 age-matched controls into a multi-center, hospital-based case-control study in Senegal, Ghana, Nigeria, and South Africa. Participants completed an epidemiologic questionnaire, and anthropometric factors were measured at clinic visit. Multivariable logistic regression was used to examine associations of overall and central obesity with PCa risk, measured by body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR), respectively.

RESULTS

Among controls 16.4% were obese (BMI ≥ 30 kg/m2), 26% and 90% had WC > 97 cm and WHR > 0.9, respectively. Cases with aggressive PCa had lower BMI/obesity in comparison to both controls and cases with less aggressive PCa, suggesting weight loss related to cancer. Overall obesity (odds ratio: OR = 1.38, 95% CI 0.99-1.93), and central obesity (WC > 97 cm: OR = 1.60, 95% CI 1.10-2.33; and WHtR > 0.59: OR = 1.68, 95% CI 1.24-2.29) were positively associated with D'Amico intermediate-risk PCa, but not with risks of total or high-risk PCa. Associations were more pronounced in West versus South Africa, but these differences were not statistically significant.

DISCUSSION

The high prevalence of overall and central obesity in African men and their association with intermediate-risk PCa represent an emerging public health concern in Africa. Large cohort studies are needed to better clarify the role of obesity and PCa in various African populations.

Validating an Instrument for Direct Patient Reporting of Distress and Chemotherapy-Related Toxicity among South African Cancer Patients

Patient-reported outcome measures (PROM) for monitoring treatment toxicity improve quality of life (QoL) and clinical outcomes. However, no such PROMs exist for sub-Saharan African cancer patients. We aimed to validate the Patient Reported Symptoms-South Africa (PRS-SA) survey, a novel PROM for measuring distress and chemotherapy-related symptoms in South African cancer patients. We enrolled patients at the oncology clinic at Charlotte Maxeke Hospital, Johannesburg. At three separate visits, participants simultaneously completed the PRS-SA survey and several previously validated questionnaires. We constructed a receiver operator characteristics curve for distress levels predicting a Hospital Anxiety and Depression Scale (HADS) score ≥15. We evaluated construct validity for symptom items by comparing severity to the EORTC Core Quality of Life Questionnaire (QLQ-C30) summary score (Pearson correlation tests) and ECOG performance status (Mann-Whitney U tests). We assessed symptom item responsiveness by comparing change in severity to change in QLQ-C30 summary score and comparing standardized mean scores with negative, no, or positive change on the Global Impression of Change (GIC) questionnaire (Jockheere-Terpstra trend test). Overall, 196 participants with solid tumors completed instruments. A distress score of 4 had 82% sensitivity and 55% specificity for clinical depression/anxiety. All symptom items showed construct validity by association with either QLQ-C30 score or performance status (highest p = 0.03). All but cough showed responsiveness to change in QLQ-C30 score (highest p = 0.045). In South African cancer patients, the PRS-SA's stress scale behaves similarly to the distress thermometer in other populations, and the symptom items demonstrated construct validity and responsiveness. Of note, 46% and 74% of participants who completed the PRS-SA in English or isiZulu, respectively, required assistance reading half or more of the instrument.

Adherence to the South African food based dietary guidelines may reduce breast cancer risk in black South African women: the South African Breast Cancer (SABC) study

OBJECTIVE

To determine the level of adherence and to assess the association between higher adherence to the South African food based dietary guidelines (SAFBDG) and breast cancer risk.

DESIGN

Population-based, case-control study (the South African Breast Cancer study) matched on age and demographic settings. Validated questionnaires were used to collect dietary and epidemiological data. To assess adherence to the SAFBDG, a nine-point adherence score (out of eleven guidelines) was developed, using suggested adherence cut-points for scoring each recommendation (0 and 1). When the association between higher adherence to the SAFBDG and breast cancer risk was assessed, data-driven tertiles among controls were used as cut-points for scoring each recommendation (0, 0·5 and 1). OR and 95 % CI were estimated using multivariate logistic regression models.

SETTING

Soweto, South Africa.

PARTICIPANTS

Black urban women, 396 breast cancer cases and 396 controls.

RESULTS

After adjusting for potential confounders, higher adherence (>5·0) to the SAFBDG v. lower adherence (<3·5) was statistically significantly inversely associated with breast cancer risk overall (OR = 0·56, 95 % CI 0·38, 0·85), among postmenopausal women (OR = 0·64, 95 % CI 0·40, 0·97) as well as for oestrogen-positive breast cancers (OR = 0·51, 95 % CI 0·32, 0·89). Only 32·3 % of cases and 39·1 % of controls adhered to at least half (a score >4·5) of the SAFBDG.

CONCLUSIONS

Higher adherence to the SAFBDG may reduce breast cancer risk in this population. The concerning low levels of adherence to the SAFBDG emphasise the need for education campaigns and to create healthy food environments in South Africa to increase adherence to the SAFBDG.

Dietary Patterns and Breast Cancer Risk in Black Urban South African Women: The SABC Study

A total of 396 breast cancer cases and 396 population-based controls from the South African Breast Cancer study (SABC) matched on age and demographic settings was included. Validated questionnaires were used to collect dietary and epidemiological data. Dietary patterns were derived using principal component analysis with a covariance matrix from 33 food groups. Odds ratios and 95% confidence intervals were estimated using conditional logistic regression. A traditional, a cereal-dairy breakfast and a processed food dietary pattern were identified, which together explained 40.3% of the total variance in the diet. After adjusting for potential confounders, the traditional dietary pattern and cereal-dairy breakfast dietary pattern were inversely associated with breast cancer risk (highest tertile versus lowest tertile) (OR = 0.72, 95%CI: 0.57-0.89, p-trend = 0.004 and OR = 0.73, 95%CI: 0.59-0.90, p-trend = 0.004, respectively). The processed food dietary pattern was not significantly associated with breast cancer risk. The results of this study show that a traditional dietary pattern and a cereal-dairy breakfast dietary pattern may reduce the risk of developing breast cancer in this population.

213 Can Styloid Process and Internal Carotid Artery Anatomy Be Used to Predict Carotid Artery Dissection?

Aim

Carotid artery dissection is a common cause of stroke in the young. It has been related to the association of the carotid artery with fixed neighbouring anatomical structures. This study assesses the association between styloid process length, internal carotid artery position and cervical carotid artery dissection (CCAD). This information would provide potential predicative radiological measurements, which could prevent delays in CCAD diagnosis.

Method

Retrospective data was collected from two central London hospitals over five years. CCAD cases were identified from individuals who underwent computer topography angiography (CTA) of the neck for suspected CCAD. The following data was collected: evidence of CCAD; bilateral styloid process length and presence of styloid-hyoid ligament calcification; bilateral styloid process-internal carotid distance; calcification of carotid arteries and whether their position was aberrant. Cases were dissection-side, age and gender matched with two non-dissection controls.

Results

Three hundred and fifty-five individuals were identified. Fifty individuals had CCAD, of which 4 had bilateral dissection. In individuals with CCAD, average styloid process length was 27.5mm and styloid process-internal carotid distance was 5.14mm. There was no significant association between styloid process length or styloid process-internal carotid distance, and CCAD when compared with matched controls. Internal carotid artery aberrancy was significant for non-dissection.

Conclusions

In this study, there was no association between styloid process length and styloid process-internal carotid distance with CCAD. These measurements cannot be used to predict the possibility of a CCAD following trauma.

Survival of south african women with breast cancer receiving anti-retroviral therapy for HIV

PURPOSE

Breast cancer outcomes in sub-Saharan Africa is reported to be poor, with an estimated five-year survival of 50% when compared to almost 90% in high-income countries. Although several studies have looked at the effect of HIV in breast cancer survival, the effect of ARTs has not been well elucidated.

METHODS

All females newly diagnosed with invasive breast cancer from May 2015-September 2017 at Charlotte Maxeke Johannesburg Academic and Chris Hani Baragwanath Academic Hospital were enrolled. We analysed overall survival and disease-free survival, comparing HIV positive and negative patients. Kaplan-Meier survival curves were generated with p-values calculated using a log-rank test of equality while hazard ratios and their 95% confidence intervals (CIs) were estimated using Cox regression models.

RESULTS

Of 1019 patients enrolled, 22% were HIV positive. The overall survival (95% CI) was 53.5% (50.1-56.7%) with a disease-free survival of 55.8% (52.1-59.3) after 4 years of follow up. HIV infection was associated with worse overall survival (HR (95% CI): 1.50 (1.22-1.85), p < 0.001) and disease-free survival (OR (95% CI):2.63 (1.71-4.03), p < 0.001), especially among those not on ART at the time of breast cancer diagnosis. Advanced stage of the disease and hormone-receptor negative breast cancer subtypes were also associated with poor survival.

CONCLUSION

HIV infection was associated with worse overall and disease-free survival. HIV patients on ARTs had favourable overall and disease-free survival and with ARTs now being made accessible to all the outcome of women with HIV and breast cancer is expected to improve.

Validating an instrument for direct patient reporting of chemotherapy toxicity among South African cancer patients

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Background: In the USA, use of patient-reported outcome (PRO) instruments for monitoring treatment toxicity has been associated with improved patient quality of life (QoL) and clinical outcomes. No similar PRO tools exist for the African cancer patients. We aimed to validate the Patient Reported Symptoms – South Africa (PRS-SA) survey, a novel PRO tool designed to measure subjective stress and symptoms in South African (SA) cancer patients receiving chemotherapy. Methods: We enrolled patients receiving chemotherapy at the oncology clinic at Charlotte Maxeke Hospital, Johannesburg. At 3 separate visits, participants completed the PRS-SA survey, which allowed reporting of stress on a numerical ranking scale (range 0-10) and severity of 11 common chemotherapy-related symptoms (i.e., pain, fatigue, fever, dyspnea, cough, mucositis, nausea, vomiting, diarrhea, constipation, and neuropathy) using lay language descriptions corresponding to Common Terminology Criteria for Adverse Events grades. They simultaneously completed the EORTC Core Quality of Life Questionnaire (QLQ-C30), the Global Impression of Change (GIC) questionnaire, and the Hospital Anxiety and Depression Scale (HADS). All instruments were offered in English and isiZulu. We constructed a receiver operator characteristics (ROC) curve for stress scale values and a total HADS score ≥15, representing clinical depression/anxiety. We evaluated construct validity for each symptom item by comparing symptom severity to the simultaneous QLQ-C30 summary score (Pearson correlation tests) and ECOG performance status (PS) (Mann-Whitney U tests). We assessed symptom item responsiveness by comparing change in severity across visits to change in QLQ-C30 summary score and comparing standardized mean symptom scores in those reporting negative, no, or positive change on the GIC using a Jockheere-Terpstra trend test. Results: Overall, 196 participants completed instruments at visit 1, 173 at visit 2, and 150 at visit 3. Area under the ROC curve for stress score was 0.76, and a score of 4 had 82% sensitivity and 55% specificity for clinical depression/anxiety. All symptom items showed construct validity by association with QLQ-C30 score (all p-values < 0.0001), and all but mucositis showed validity by association with ECOG PS (highest p = 0.03). All but cough showed responsiveness to change in QLQ-C30 score (highest p = 0.045), and the standardized mean in symptom scores demonstrated a trend across negative, neutral, and positive GIC scores (p = 0.03). Conclusions: In SA cancer patients, the PRS-SA’s stress scale behaves similarly to the distress thermometer in other populations, and the symptom items demonstrated construct validity and responsiveness. Further research should address implementation of the PRS-SA in the clinical setting for monitoring cancer treatment-related toxicity and its impact of patients’ QoL and outcomes.

Quality of Histopathological Reporting in Breast Cancer: Results From Four South African Breast Units

PURPOSE

High-quality histopathology reporting forms the basis for treatment decisions. The quality indicator for pathology reports from the European Society of Breast Cancer Specialists was applied to a cohort from four South African breast units.

METHODS

The study included 1,850 patients with invasive breast cancer and evaluated 1,850 core biopsies and 1,158 surgical specimen reports with cross-center comparisons. A core biopsy report required histologic type; tumor grade; and estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) status, with a confirmatory test for equivocal HER2 results. Ki-67 was regarded as optional. Pathologic stage, tumor size, lymphovascular invasion, and distance to nearest invasive margin were mandatory for surgical specimens. Specimen turnaround time (TAT) was added as a locally relevant indicator.

RESULTS

Seventy-five percent of core biopsy and 74.3% of surgical specimen reports were complete but showed large variability across study sites. The most common reason for an incomplete core biopsy report was missing tumor grade (17.9%). Half of the equivocal HER2 results lacked confirmatory testing (50.6%). Ki-67 was reported in 89.3%. For surgical specimens, the closest surgical margin was reported in 78.1% and lymphovascular invasion in 84.8% of patients. Mean TAT was 11.9 days (standard deviation [SD], 10.8 days) for core biopsies and 16.1 days (SD, 11.3) for surgical specimens.

CONCLUSION

Histopathology reporting is at a high level but can be improved, especially for tumor grade, HER2, and Ki-67, as is reporting of margins and lymphovascular invasion. A South African pathology consensus will reduce variability among laboratories. Routine use of standardized data sheets with synoptic reports and ongoing audits will improve completeness of reports over time.

O28 Can styloid process and internal carotid artery anatomy be used to predict carotid artery dissection?

Introduction

Carotid artery dissection is a common cause of stroke in the young. It has been related to the association of the carotid artery with fixed neighbouring anatomical structures. This study assesses the association between styloid process length, internal carotid artery position and cervical carotid artery dissection (CCAD). This information would provide potential predicative radiological measurements, which could prevent delays in CCAD diagnosis.

Method

Retrospective data was collected from two central London hospitals over five years. CCAD cases were identified from individuals who underwent computer topography angiography (CTA) of the neck for suspected CCAD. The following data was collected: evidence of CCAD; bilateral styloid process length and presence of styloid-hyoid ligament calcification; bilateral styloid process-internal carotid distance; calcification of carotid arteries and whether their position was aberrant. Cases were dissection-side, age and gender matched with two non-dissection controls.

Result

Three hundred and fifty-five individuals were identified. Fifty individuals had CCAD, of which 4 had bilateral dissection. In individuals with CCAD, average styloid process length was 27.5 mm and styloid process-internal carotid distance was 5.14 mm. There was no significant association between styloid process length or styloid process-internal carotid distance, and CCAD when compared with matched controls. Internal carotid artery aberrancy was significant for non-dissection.

Conclusion

In this study, there was no association between styloid process length and styloid process-internal carotid distance with CCAD. These measurements can not be used to predict the possibility of a CCAD following trauma.

Take-home Message

Anatomy of the styloid process and calcification of the styloid-hyoid ligament are highly variable and many independent factors may contribute to the risk of cervical carotid artery dissection. Radiological measurements of the styloid process alone cannot be used to predict risk and likelihood of cervical carotid artery dissection.

The impact of HIV infection on overall survival among women with stage IV breast cancer in South Africa

6559

Background: Advanced stage at breast cancer (BC) diagnosis is common in sub-Saharan Africa. In public hospitals across South Africa (SA), 10-15% of women present with metastatic BC, compared to <5% in the U.S., and 20% of new BCs are diagnosed in women living with HIV (WLWH). We evaluated the impact of HIV on overall survival (OS) among women with stage IV BC, which is associated with a poor prognosis in SA. Methods: We conducted a prospective cohort study of women diagnosed with stage IV BC between February 2, 2015 and September 18, 2019 at six public hospitals in SA. Baseline characteristics were compared by HIV status and multivariate Cox regression models were used to estimate the effect of HIV on OS. Results: Among 550 eligible women, 147 (26.7%) were WLWH. Compared to HIV-negative BC patients, WLWH were younger (median age 45 vs. 60 years, p<0.001), predominantly black (95.9% vs. 77.9%, p<0.001), and more likely to have hormone receptor-negative BC (32.7% vs. 22.6%, p=0.016). HER2 tumor status did not differ by HIV status (25.3% HER2 positive overall), and Ki67 index was not increased among WLWH (57.1% Ki67 > 20 overall). Receipt of systemic anti-cancer therapy did not differ by HIV status (80.9% treated overall) and most women were treated with anthracycline (55.5%). HIV status was not associated with OS (Hazard Ratio (HR)=1.13, 95% confidence interval (CI)=0.89-1.44) (Table). In an exploratory subgroup analysis, WLWH and hormone receptor-negative BC had shorter OS compared to HIV-negative women (1-year OS: 27.1% vs. 48.8%, p=0.003; HR=1.94, 95% CI=1.27-2.94), which was not observed for hormone receptor-positive BC. Results were unchanged when analysis was restricted to black women only. Conclusions: HIV status was not associated with worse OS in women with stage IV BC in SA and cannot account for the poor survival in our cohort. Subgroup analysis revealed that WLWH with hormone receptor-negative BC had worse OS; this differential effect of HIV on BC survival by hormone receptor status is a novel finding that warrants further investigation.[Table: see text]

Preexisting morbidity profile of women newly diagnosed with breast cancer in sub-Saharan Africa: African Breast Cancer-Disparities in Outcomes study

The presence of preexisting morbidities poses a challenge to cancer patient care. There is little information on the profile and prevalence of multi-morbidities in breast cancer patients across middle income countries (MIC) to lower income countries (LIC) in sub-Saharan Africa (SSA). The African Breast Cancer-Disparities in Outcomes (ABC-DO) breast cancer cohort spans upper MICs South Africa and Namibia, lower MICs Zambia and Nigeria and LIC Uganda. At cancer diagnosis, seven morbidities were assessed: obesity, hypertension, diabetes, asthma/chronic obstructive pulmonary disease, heart disease, tuberculosis and HIV. Logistic regression models were used to assess determinants of morbidities and the influence of morbidities on advanced stage (stage III/IV) breast cancer diagnosis. Among 2189 women, morbidity prevalence was the highest for obesity (35%, country-specific range 15-57%), hypertension (32%, 15-51%) and HIV (16%, 2-26%) then for diabetes (7%, 4%-10%), asthma (4%, 2%-10%), tuberculosis (4%, 0%-8%) and heart disease (3%, 1%-7%). Obesity and hypertension were more common in upper MICs and in higher socioeconomic groups. Overall, 27% of women had at least two preexisting morbidities. Older women were more likely to have obesity (odds ratio: 1.09 per 10 years, 95% CI 1.01-1.18), hypertension (1.98, 1.81-2.17), diabetes (1.51, 1.32-1.74) and heart disease (1.69, 1.37-2.09) and were less likely to be HIV positive (0.64, 0.58-0.71). Multi-morbidity was not associated with stage at diagnosis, with the exception of earlier stage in obese and hypertensive women. Breast cancer patients in higher income countries and higher social groups in SSA face the additional burden of preexisting non-communicable diseases, particularly obesity and hypertension, exacerbated by HIV in Southern/Eastern Africa.

Reproductive factors and risk of breast cancer in black South African women

PURPOSE

Breast cancer (BC) is increasing in black South African women, but few studies have investigated its risk factors.

METHODS

We conducted an analysis of reproductive factors and BC risk in the South African Breast Cancer (SABC) study-a population-based case-control study of black South African women from Soweto that included 399 cases and 399 matched controls. Information on lifestyle and reproductive history was obtained by interviews. Conditional logistic regression was used to determine the association of reproductive factors with BC, adjusting for potential confounding factors.

RESULTS

Seventy-five percent of all BC cases were ER+, 66% PR+, 30% HER2+, and 16% TN. None of the reproductive variables were associated with BC overall or by subtype in the overall population, nor in pre- (n = 135 cases) or in post-menopausal women separately. In HIV-negative pre-menopausal women (n = 97 cases), later age at first pregnancy and longer time between menarche and first full-time pregnancy were inversely related to BC risk (OR 0.89 (95% CI 0.82-0.97; and 0.93 95% CI 0.86-1.01, respectively).

CONCLUSION

In this population of black South African women, reproductive factors were not associated with BC risk.

Consensus study on the health system and patient-related barriers for lung cancer management in South Africa

BACKGROUND

Lung cancer is the highest incident cancer globally and is associated with significant morbidity and mortality particularly if identified at a late stage. Poor patient outcomes in low- and middle-income countries (LMIC's) might reflect contextual patient and health system constraints at multiple levels, that act as barriers to prevention, disease recognition, diagnosis, and treatment. Lung cancer screening, even for high-risk patients, is not available in the public health sector in South Africa (SA), where the current HIV and tuberculosis (TB) epidemics often take precedence. Yet, there has been no formal assessment of the individual and health-system related barriers that may delay patients with lung cancer from seeking and accessing help within the public health care system and receiving the appropriate and effective diagnosis and treatment. This study aimed to derive consensus from health-system stakeholders in the urban Gauteng Province of SA on the most important challenges faced by the health services and patients in achieving optimum lung cancer management and to identify potential solutions.

METHODS

The study was undertaken among 27 participant stakeholders representing clinical managers, clinicians, opinion leaders from the public health sector and non-governmental organisation (NGO) representatives. The study compromised two components: consensus and engagement. For the consensus component, the Delphi Technique was employed with open-ended questions and item ranking from five rounds of consensus-seeking, to achieve collective agreement on the most important challenges faced by patients and the health services in achieving optimal lung cancer management. For the engagement component, the Nominal Group Technique was used to articulate ideas and reach an agreement on the group's recommendations for solution strategies and approaches.

RESULTS

Public health sector stakeholders suggested that a lack of knowledge and awareness of lung cancer, and the apparent stigma associated with the disease and its risk factors, as well as symptoms and signs, are critical to treatment delay. Furthermore, delays in up-referral of patients with suspected lung cancer from district health care level were attributed to inadequate knowledge arising from a lack of in-service training of nurses and doctors regarding oncologic symptoms, risk factors, need for further investigation, interpretation of x-rays and available treatments. At a tertiary level, participants suggested that insufficient availability of specialised diagnostic resources (imaging, cytological and pathological services including biomolecular assessment of lung cancer), theatres, cardiothoracic surgeons, and appropriate therapeutic modalities (chemotherapeutic agents and radiation oncology) are the main barriers to the provision of optimal care. It was suggested that a primary prevention programme initiated by the government that involves private-public partnerships may improve lung cancer management nationally.

CONCLUSIONS

Considerable barriers to the early identification and treatment of lung cancer exist. Finding solutions to overcome both individual and health-system level obstacles to lung cancer screening and management are vital to facilitate early identification and treatment, and to improve survival. Furthermore, research on inexpensive biomarkers for asymptomatic disease detection, the introduction of diagnostic imaging tools that utilise artificial intelligence to compensate for inadequate human resources and improving clinical integration across all levels of the healthcare system are essential.

Ki67 Immunohistochemistry Quantification in Breast Carcinoma: A Comparison of Visual Estimation, Counting, and ImmunoRatio

BACKGROUND

Molecular analysis has shown that breast carcinomas can be classified into several intrinsic subtypes, with implications for management and prognosis. In the majority of pathology laboratories molecular analysis of each case is not possible and immunohistochemistry is used for subtyping. This includes analysis of hormone receptors as well as HER2-neu and Ki67. The methodology for the interpretation of the proliferation index using Ki67 remains an area of uncertainty. We investigated the degree of agreement between different methods of Ki67 interpretation.

MATERIALS AND METHODS

We analyzed 204 breast core biopsies diagnostic of breast carcinoma using visual estimation/eyeballing (EB), ImmunoRatio, and counting by 2 pathologists (CP1 and CP2). The correlation between the different methods and the interobserver agreement between the 2 pathologists was assessed. Specific analysis was also done with respect to classification of cases into low Ki67 groups (using Ki67 values<14% and <20%) since this is critical in classifying tumors into luminal A and luminal B subtypes.

RESULTS

Correlation between the different methods was best achieved comparing ImmunoRatio and CP1, and worst comparing CP1 and EB. Correlation was better when considering interobserver variability (CP1 vs. CP2). Comparing the number of cases classified as low Ki67 (<14% and <20%) the Cohen κ statistic varied from κ=0.267 to 0.814 with different methods. When limiting the analysis to cases with a Ki67 of 10% to 25% according to any method, there was greater disagreement.

CONCLUSIONS

At the higher and lower Ki67 levels, the correlation between the methods of assessment was acceptable, however, at levels close to the cut-off values for lumial A versus luminal B, several patients would be differently classified by the different methods and therefore potentially receive suboptimal management.

The Value of Navigators in Breast Cancer Management in a South African Hospital

BACKGROUND

Specialist breast cancer nurses (BCNs) have improved the psychological care and follow-up rates of breast cancer (BC) patients. This study sought to determine if breast cancer research workers (BCRWs) as de facto BCNs impacted patients' adherence to treatment by comparing groups with and without these patient navigators; hence assessing our need for BCNs.

METHODS

Two groups BC patients booked for primary chemotherapy compared. Study group 1 (SG1): no BCRWs/BCNs. Study group 2 (SG2): BCRWs involvement. Assessment of numbers completing primary chemotherapy, undergoing surgery post-neoadjuvant chemotherapy and BCRWs interventions.

RESULTS

SG1: n = 281, 25-89y, mean 52.7y, Stage 4: 35.6%, Stage 3: 64.4%. SG2: n = 154, 21-85y, mean 52.6y, Stage 4: 47.4%, Stage 3: 43.3%, Stage 2: 9%. Primary chemotherapy not completed SG1: 40.2% (113) versus SG2: 13.5% (21); p < 0.00001. SG1: 88% not completing were lost to follow-up. Excluding peri-chemotherapy deaths and discontinuation: SG1: 37.1% did not complete chemotherapy versus SG2: 2.6%, p < 0.00001. SG2: BCRWs: 107 interventions for 58 (37.7%) patients. Therapeutic breast surgery SG1: 103/181 (56.9%) versus SG2: 66/81 (81.5%); p < 0.0001. SG1: main reasons for not having surgery: lost to follow-up during (n = 58) or after (n = 9) chemotherapy. Follow-up SG2: 12-43 months, mortality: 52% (80/154), no lost to follow-ups. SG1: No mortality data.

CONCLUSIONS

In our setting, BC patients often do not attend or complete treatments. In this study, BCRWs as de-facto BCNs were beneficial for BC patient care, improving chemotherapy compliance and therapeutic surgical interventions. This highlights the need for BCNs for the management of BC patients in South Africa.