Breast cancer risk factors in relation to molecular subtypes in breast cancer patients from Kenya

Breast cancer molecular subtype classification according to immunohistochemistry markers and its association with pathological characteristics among women attending tertiary hospitals in Tanzania

Background

Breast cancer immunohistochemistry is a biological characteristic of the tumour which has a role to diagnose molecular subtype, prognosticate and guide treatment and is categorised into 4 subtypes. Data in Tanzania was lacking and was based off data extrapolated from studies in Western Africa thus hypothesizing that women of African ancestry predominately develop Triple Negative Breast Cancer (TNBC).

Methods

A retrospective cross-sectional study was carried out at two tertiary referral hospitals on participants who were recruited from the cancer registries from 2015 to 2022. Prevalence of each molecular subtype was determined and association between molecular subtype to demographic and pathological characteristics were evaluated. Predictors of molecular subtypes was then determined using logistic regression.

Results

Total number of participants were 1214, median age was 50 (IQR: 41-61), median tumor size was 5 cm (IQR: 4-7) with lymph node positivity in 73.7 %. Immunohistochemistry studies showed estrogen, progesterone and Human Epidermal Growth Factor Receptor 2 (HER2) receptor positivity in 54.4 %, 34.4 % and 27.8 % of cases respectively. Molecular subtype classification prevalence for Luminal A was 21.17 % (95 % CI: 18.87-23.47), for Luminal B 35.75 % (95 % CI: 33.05-38.45), for HER2 enriched 11.86 % (95 % CI: 10.04-13.68) and for TNBC 31.22 % (95 % CI: 28.61-33.83). Significant association was seen between molecular subtype with age, tumor size, tumor grade and lymph node involvement. Predictors of Luminal tumors were larger tumor size (aOR 1.217, 95 % CI: 1.149-1.291) no lymph node involvement (aOR 0.429, 95 % CI: 0.313-0.589) while an advanced tumor grade reduced likelihood (aOR 0.041, 95 % CI: 0.011-0.019).

Conclusion

In Tanzania Luminal B was most predominant subtype presenting at an earlier age and associated with more favorable pathological characteristics.

Relationship between early age at menarche, older age at menopause and subtypes of breast cancer: a scoping review

Objective

To determine the relationship between early age at menarche, late age at menopause with specific subtypes of breast cancer (BC).

Methods

A literature search was conducted in Embase, Lilacs, PubMed, Scopus, and Scielo databases, following the Joanna Briggs Institute scoping review protocol and answering the question "How early age at menarche or late age at menopause are related to different breast cancer subtypes?".

Results

A number of 4,003 studies were identified, of which 17 were selected. Most of the included articles found a clear relationship between early menarche, late menopause and some subtypes of BC, mainly, PR+, ER+, luminal, and HER-2 tumors. However, some studies have found a contradictory relationship and one study didn't find any relationship between them.

Conclusion

A relationship between early age at menarche and advanced age at menopause was observed with some subtypes of breast cancer, since other factors must be considered in its understanding.

Breastfeeding and its Association with Breast Cancer: a Systematic Review of the Literature

Objective:Breast cancer is a global public health issue. The disease can be diagnosed in both older and younger women, with the latter facing several dilemmas. Breastfeeding is of general concern to the scientific community as well as its connection with the prevention of breast cancer is being sought. The purpose of this review is to search for studies investigating the relationship between breast cancer and breastfeeding. Material and methods: The articles included in the present paper were searched in PubMed and Scopus databases according to PRISMA guidelines for systematic reviews. This systematic review sought primary studies investigating the relationship between breastfeeding and breast cancer and that were published in English between 2017-2022. Results:Seventeen articles that investigated the relationship of breast cancer with lactation duration, women's age, family history and lifestyle were included in the present review. Conclusion:It was found that, in most studies, breastfeeding could be evaluated as a protective factor of the disease. From all studied articles, the need for the design of additional studies investigating the relationship between breastfeeding and breast cancer emerges.

Ultrasound Radiomics for the Prediction of Breast Cancers with HER2-Zero, -Low, and -Positive Status: A Dual-Center Study

PURPOSE

To assess whether gray-scale ultrasound (US) based radiomic features can help distinguish HER2 expressions (ie, HER2-overexpressing, HER2-low-expressing, and HER2-zero-expressing) in breast cancer.

MATERIALS AND METHODS

This retrospective study encompassed female breast cancer patients who underwent US examinations at two distinct centers from February 2021 to July 2023. Tumor segmentation and radiomic feature extraction were performed on grayscale US images. Decision Tree analysis was employed to simultaneously evaluate feature importance, and the Least Absolute Shrinkage and Selection Operator technique was utilized for feature selection to construct the radiomic signature. The Area Under the Curve (AUC) of the Receiver Operating Characteristic curve was employed to assess the performance of the radiomic features. Multivariate logistic regression was used to identify independent predictors for distinguishing HER2 expression in the dataset.

RESULTS

The training set comprised 292 patients from Center 1 (median, 51 years; interquartile range [IQR]: 45-61), while the external validation set included 131 patients from Center 2 (median, 51 years; IQR: 45-62). In the external validation dataset, the radiomic features achieved AUC of 0.76 for distinguishing between HER2-low and positive tumors versus HER2-zero tumors. The AUC for differentiating HER2-low (1+) from HER2-zero tumors was 0.74, and for distinguishing HER2-low (2+) from HER2-zero tumors, the AUC was 0.77. In the multivariate analysis assessing HER2-low and HER2-positive versus HER2-zero tumors, internal echoes (P = .029) and margins (P < .001) emerged as independent predictive factors.

CONCLUSION

The radiomic signature and tumor descriptors from gray-scale US may predict distinct HER2 expressions of breast cancers with therapeutic implications.

Oncogenic roles of GPR176 in breast cancer: a potential marker of aggressiveness and a potential target of gene therapy

BACKGROUND

Belonging to the G-protein coupled receptor 1 family, G protein-coupled receptor 176 (GPR176) is associated with the Gz/Gx G-protein subclass and is capable of decreasing cAMP production.

METHODS

GPR176 expression was detected by qRT-PCR, bioinformatics analysis, Western blot and immunohistochemistry, and compared with clinicopathological characteristics of breast cancer. GPR176-related genes and pathways were subjected to bioinformatic analysis. We also explored the effects of GPR176 on the phenotypes of breast cancer cells.

RESULTS

Lower expression of GPR176 mRNA was seen in breast cancer than in normal tissues, but the opposite pattern was found for its protein (p < 0.05). GPR176 mRNA was associated with female sex, low T staging, non-Her-2+ subtypes, non-mutant p53 status in breast cancer (p < 0.05). GPR176 methylation was negatively correlated with its mRNA level and T staging in breast cancer, and was higher in breast cancer than normal tissues (p < 0.05). GPR176 protein expression was positively correlated with older age, small tumor size, and non-luminal-B subtype of breast cancers (p < 0.05). The differential genes of GPR176 were involved in receptor-ligand interaction, RNA maturation, and so forth (p < 0.05). GPR176-related genes were categorized into cell mobility, membrane structure, and so on (p < 0.05). GPR176 knockdown weakened the proliferation, glucose catabolism, anti-apoptosis, anti-pyroptosis, migration, invasion, and epithelial-mesenchymal transition of breast cancer cells.

CONCLUSION

These results indicate that GPR176 might be involved in the tumorigenesis and subsequent progression of breast cancer by deteriorating aggressive phenotypes. It might be utilized as a potential biomarker to indicate the aggressive behaviors and poor prognosis of breast cancer and a potential target of genetic therapy.

Immunohistochemistry versus PCR Technology for Molecular Subtyping of Breast Cancer: Multicentered Expereinces from Addis Ababa, Ethiopia

The application of immunohistochemistry (IHC) for molecular characterization of breast cancer (BC) is of paramount importance; however, it is not universally standardized, subject to observer variability and quantifying is a challenge. An alternative molecular technology, such as endpoint reverse transcription (RT)-PCR gene expression analysis, may improve observer variability and diagnostic accuracy. This study was intended to compare IHC with the RT-PCR based technique and assess the potential of RT-PCR for molecular subtyping of BC. In this comparative cross-sectional study, 54 BC tissues were collected from three public hospitals in Addis Ababa and shipped to Gynaecology department at Martin-Luther University (Germany) for laboratory analysis. Only 41 samples were qualified for IHC and RT-PCR investigation of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 protein expression analysis. Kappa statistics was used to assess the concordance between the two techniques. The overall percent agreement between RT-PCR and IHC was 68.3% for ER (positive percent agreement [PPA] 71.1%; negative percent agreement [NPA] 33.3%), 39.0% for PR (PPA 14.3%; NPA 92.3%), and 82.9% for HER2 (PPA 62.5%; NPA 87.9%). Cohen's κ-values of 0.018 (< 0.20), 0.045 (< 0.200), and 0.481 (0.41-0.60) were generated for ER, PR, and HER2, respectively. Concordance for molecular subtypes was only 56.1% (23/41) and 0.20 kappa value. IHC and endpoint RT-PCR techniques have shown to be discordant for 43% samples. Molecular subtyping using endpoint RT-PCR was fairly concordant with IHC. Thus, endpoint RT-PCR may give an objective result, and can be applied for BC subtyping.

Adaptive immune receptor features related to breast cancer tissue in Kenyan patients: high immunoglobulin gene expression and high levels of gamma-delta T-cells

BACKGROUND

Characterization of the breast cancer (BC) immune response may provide information for a point of intervention, such as application of immunotherapeutic treatments. In this study, we sought to recover and characterize the adaptive immune receptor (IR) recombination reads from genomics files representing Kenyan patients, to better understand the immune response specifically related to those patients.

METHODS

We used a previously applied algorithm and software to obtain productive IR recombination reads from cancer and adjacent normal tissue samples representing 22 Kenyan BC patients.

RESULTS

From both the RNAseq and exome files, there were significantly more T-cell receptor (TCR) recombination reads recovered from tumor samples compared to marginal tissue samples. Also, the immunoglobulin (IG) genes were expressed at a much higher level than the TCR genes (p-value = 0.0183) in the tumor samples. And, the tumor IG CDR3s consistently represented more positively charged amino acid R-groups, in comparison to the marginal tissue, IG CDR3s.

CONCLUSION

For Kenyan patients, a high level of IG expression, representing specific CDR3 chemistries, was associated with BC. These results lay the foundation for studies that could support specific immunotherapeutic interventions for Kenyan BC patients.

Disparities in stage at diagnosis among breast cancer molecular subtypes in China

BACKGROUND

Disease stage at diagnosis and molecular subtypes are the main determinants of breast cancer treatment strategies and prognosis. We aimed at examining the disparities and factors associated with the stage at diagnosis among the molecular subtypes in breast cancer patients in China.

METHODS

We identified patients with first primary breast cancer diagnosed between January 1, 2016, and December 31, 2017, from 23 hospitals in 12 provinces in China. We analyzed the proportion of non-early-stage (stages II-IV) breast cancer cases based on the family history of breast cancer, body mass index (BMI), insurance status, and molecular subtypes. Multivariable analyses were used to estimate the factors associated with non-early-stage diagnosis among the molecular subtypes. We further compared these estimates with that in the United States using the Surveillance, Epidemiology, and End Results database.

RESULTS

A total of 9398 Chinese were identified with first primary invasive breast cancer. Of the 8767 patients with known stages, the human epidermal growth factor receptor 2 (HER2)-enriched subtype had the highest proportion of stages II-IV (76.6%) patients, followed by triple-negative breast cancer (73.2%), luminal B (69.9%), and luminal A (62.3%). The percentage of non-early-stage patients was higher in women with overweight or obesity than in those with a body mass index (BMI) <25 kg/m2 (adjusted odds ratio [OR] 1.3, 95% confidence interval (CI) 1.1-1.4). Patients with a family history of breast cancer had a higher likelihood of early-stage (adjusted OR 0.7, 0.5-0.8) breast cancer. Patients with rural insurance had a substantially higher risk of non-early-stage disease than those with urban insurance (adjusted OR 1.8, 1.4-2.2). Regarding the subtype, being overweight/obese only increased the risk of non-early-stage in luminal A breast cancer. Compared with the United States, China had a higher proportion of non-early-stage breast cancer for all subtypes, with the largest gap in luminal A (adjusted OR 2.2, 95% CI 2.0-2.4).

CONCLUSION

The wide disparities in stage at breast cancer diagnosis imply that China urgently needs to improve early breast cancer diagnosis and health equity.

Tumour Infiltrating Lymphocytes (TILs) and immune composition in breast cancer patients from Kenya: Spatial distributions and associations with risk factors and tumour characteristics

BACKGROUND

The immune landscape of breast cancer (BC) in patients from Sub Saharan Africa is understudied. Our aims were to describe the distribution of Tumour Infiltrating Lymphocytes (TILs) within the intratumoural stroma (sTILs) and the leading/invasive edge stroma (LE-TILs), and to evaluate TILs across BC subtypes with established risk factors and clinical characteristics in Kenyan women.

METHODS

Visual quantification of sTILs and LE-TILs were performed on Haematoxylin and eosin -stained pathologically confirmed BC cases based on the International TIL working group guidelines. Tissue Microarrays were constructed and stained with immunohistochemistry (IHC) for CD3, CD4, CD8, CD68, CD20, and FOXP3. Linear and logistic regression models were used to assess associations between risk factors and tumour features with IHC markers and total TILs, after adjusting for other covariates.

RESULTS

A total of 226 invasive BC cases were included. Overall, LE-TIL (mean = 27.9, SD = 24.5) proportions were significantly higher than sTIL (mean = 13.5, SD = 15.8). Both sTILs and LE- TILs were predominantly composed of CD3, CD8, and CD68. We found higher TILs to be associated with high KI67/high grade and aggressive tumour subtypes, although these associations varied by TIL locations. Older age at menarche (≥ 15 vs. < 15 years) was associated with higher CD3 (OR: 2.06, 95%CI:1.26-3.37), but only for the intra-tumour stroma.

CONCLUSION

The TIL enrichment in more aggressive BCs is similar to previously published data in other populations. The distinct associations of sTIL/LE-TIL measures with most examined factors highlight the importance of spatial TIL evaluations in future studies.

The distribution of reproductive risk factors disclosed the heterogeneity of receptor-defined breast cancer subtypes among Tanzanian women

Background

Recent epidemiological studies suggest that reproductive factors are associated with breast cancer (BC) molecular subtypes. However, these associations have not been thoroughly studied in the African populations. The present study aimed to investigate the prevalence of BC molecular subtypes and assess their association with reproductive factors in Tanzanian BC patients.

Methods

This hospital-based case-only cross-sectional study consisted of 263 histologically confirmed BC patients in Tanzania. Clinico-pathological data, socio-demographic characteristics, anthropometric measurements, and reproductive risk factors were examined using the Chi-square test and one-way ANOVA. The association among reproductive factors and BC molecular subtypes was analyzed using multinomial logistic regression. The heterogeneity of the associations was assessed using the Wald test.

Results

We found evident subtype heterogeneity for reproductive factors. We observed that post-menopausal status was more prevalent in luminal-A subtype, while compared to luminal-A subtype, luminal-B and HER-2 enriched subtypes were less likely to be found in post-menopausal women (OR: 0.21, 95%CI 0.10–0.41, p = 0.001; OR: 0.39, 95%CI 0.17–0.89, p = 0.026, respectively). Also, the luminal-B subtype was more likely to be diagnosed in patients aged ≤ 40 years than the luminal-A subtype (OR: 2.80, 95%CI 1.46–5.32, p = 0.002). Women who had their first full-term pregnancy at < 30 years were more likely to be of luminal-B (OR: 2.71, 95%CI 1.18–4.17, p = 0.018), and triple-negative (OR: 2.28, 95%CI 1.02–4.07, p = 0.044) subtypes relative to luminal-A subtype. Furthermore, we observed that breastfeeding might have reduced odds of developing luminal-A, luminal-B and triple-negative subtypes. Women who never breastfed were more likely to be diagnosed with luminal-B and triple-negative subtypes when compared to luminal-A subtype (OR: 0.46, 95%CI 0.22–0.95, p = 0.035; OR: 0.41, 95%CI 0.20–0.85, p = 0.017, respectively).

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Conclusion

Our results are the first data reporting reproductive factors heterogeneity among BC molecular subtypes in Tanzania. Our findings suggest that breast-feeding may reduce the likelihood of developing luminal-A, luminal-B, and triple-negative subtypes. Meanwhile, the first full-term pregnancy after 30 years of age could increase the chance of developing luminal-A subtype, a highly prevalent subtype in Tanzania. More interventions to promote modifiable risk factors across multiple levels may most successfully reduce BC incidence in Africa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01536-6.