Breast Cancer Subtype Variation by Race and Ethnicity in a Diverse Population in British Columbia

Evaluation of HER2 immunohistochemistry expression in non-standard solid tumors from a Single-Institution Prospective Cohort

Aim

Human epidermal growth factor receptor-2 (HER2) is a well-established prognostic and predictive biomarker. It is an FDA-approved therapeutic target for HER2 positive breast, gastroesophageal, and more recently, lung and colon cancers. It is an emerging biomarker in biliary tract, bladder, cervical, endometrial, ovarian, and pancreatic cancers. The emergence of new indications warrants further characterization of HER2 expression in diverse cancer populations. This study investigated HER2 expression in solid tumour samples and the feasibility of obtaining these results.

Methods

Prospective consent was obtained at a Canadian tertiary academic cancer center from adult oncology patients who were referred for molecular genetic testing of malignant tissue samples. Standard HER2-targeted malignancies were considered breast and gastroesophageal, and were excluded from this study. Between July 2020 and November 2023, 499 samples of solid tumors underwent immunohistochemistry (IHC) HER2 staining. A median turnaround time (TAT) of 14 days would be considered feasible for clinical decision making.

Results

The mean age (± SD) of participants was 67 ± 12.5 years, with 270 (54%) male and 229 (46%) female. HER2 protein expression was measured in 42 unique cancer types. IHC levels of 0, 1+, 2+, and 3+ were reported and were 43%, 12%, 35%, and 10% of all analyzable samples respectively (tissue inadequate in 3% of samples). The median TAT for HER2 expression results from time of request to result in release was 18 (interquartile range, 11 to 30) days.

Conclusions

HER2 protein expression varies widely between different cancer types. TAT for HER2 IHC results was a median of 18 days, which is close to our feasibility cut-off.

Analysis of Breast Cancer Differences between China and Western Countries Based on Radiogenomics

Using radiogenomics methods, the differences between tumor imaging data and genetic data in Chinese and Western breast cancer (BC) patients were analyzed, and the correlation between phenotypic data and genetic data was explored. In this paper, we analyzed BC patients' image characteristics and transcriptome data separately, then correlated the magnetic resonance imaging (MRI) phenotype with the transcriptome data through a computational method to develop a radiogenomics feature. The data was fed into the designed random forest (RF) model, which used the area under the receiver operating curve (AUC) as the evaluation index. Next, we analyzed the hub genes in the differentially expressed genes (DEGs) and obtained seven hub genes, which may cause Chinese and Western BC patients to behave differently in the clinic. We demonstrated that combining relevant genetic data and imaging features could better classify Chinese and Western patients than using genes or imaging characteristics alone. The AUC values of 0.74, 0.81, and 0.95 were obtained separately using the image characteristics, DEGs, and radiogenomics features. We screened SYT4, GABRG2, CHGA, SLC6A17, NEUROG2, COL2A1, and MATN4 and found that these genes were positively or negatively correlated with certain imaging characteristics. In addition, we found that the SLC6A17, NEUROG2, CHGA, and MATN4 genes were associated with clinical features.

Changing Trends in Estrogen Receptors/Progesterone Receptors/Human Epidermal Growth Factor Receptor 2 Prevalence Rates Among Jordanian Patients With Breast Cancer Over the Years

PURPOSE

Estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth factor receptor 2 (HER2) are the mainstay of breast cancer management, and their prevalence rates vary among different populations possibly related to ethnic/genetic and/or socioeconomic status. In a previous study conducted at the King Hussein Cancer Center (published 2006), Jordan ER/PR/HER2 rates for patients diagnosed in 2003-2004 were 50.8%/57.5%/17.5%, respectively. The aim of this study is to revisit the prevalence rates to see if they have changed over the years with changing socioeconomic status.

MATERIALS AND METHODS

We retrieved clinicopathologic data of all patients (1,185) diagnosed with breast cancer during 2018. The data included age, histologic type, grade, and ER/PR/HER2 status as determined by immunohistochemistry and/or fluorescence in situ hybridization for HER2.

RESULTS

The mean age of patients was 52 (median = 51, range = 25-92) years, and the majority (73.2%) had invasive carcinoma of no special type. ER/PR/HER2 were 77.0%/72.4%./23.8%, respectively. Triple-negative breast cancers were 10.1%. In comparison with previous results of 2006, the changes are statistically significant. Similar changes were seen in other Middle Eastern populations. The current rates are close to those of Western populations.

CONCLUSION

Rates of ER/PR/HER2 expression have significantly changed and are close to those of Western populations for ER/PR. We propose that such changes are secondary to the adoption of a westernized lifestyle and socioeconomic changes.

Young breast cancer and the influence of ethnicity in Sandakan: A 3-year retrospective cross-sectional study

INTRODUCTION

Breast cancer (BC) is the most common cancer in Malaysia, with incidence increasing with age. There have been demonstrated differences in age of presentation and tumour biology when comparing ethnicities. Twenty percent of Caucasian women present before 50 years old, but almost 50% of Southeast Asian (SEA) women present before 50. However, BC in Indigenous sub-groups has not yet been studied. Sandakan is a city in Sabah with a large Indigenous population. Current nationwide screening guidelines are based on the U.S. Preventive Task Force 2009 Guidelines, which may not represent our population. We aim to examine the age of incidence for our local population, for local screening recommendations.

METHOD

Retrospective cross-sectional study, including all consecutive cases of epithelial invasive tumours, from January 2016 to December 2018. Other histological types were excluded. Univariate and multivariate analyses were performed.

RESULT

A total of 115 breast tumours were identified. Ten tumours were excluded (five ductal carcinoma in situ, four phyllodes, and one sarcoma), leaving a study population of 105 patients. Median age of presentation was 53 years (min 30; max 97). A total of 41.9% presented before the age of 50. Patients of Indigenous ethnic origins were 11 years younger at presentation than non-Indigenous women. Tumour grade was more likely to be higher among Indigenous women.

CONCLUSION

Median age of presentation of BC in Sandakan matches regional data; however, patients of Indigenous ethnic groups present even earlier. Screening guidelines should consider the growing evidence of young BC in SEA.

Distribution of tumor subtypes in bilateral breast cancer: Comparison between synchronous and metachronous cancer

AIM

This study was performed to evaluate patterns of breast cancer subtypes in Korean patients with synchronous (SBC) or metachronous bilateral breast cancer (MBC).

METHODS

We retrospectively reviewed records of 302 patients with SBC (n = 161) or MBC (n = 141) who received curative surgery at our hospital between 1995 and 2013. Expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) was determined by immunohistochemistry (IHC) staining. We categorized breast cancers into the following subtypes: ER+ or PR+, HER2- (i.e., luminalA); ER+ or PR+, HER2+ (i.e., luminalB HER2+); ER-, PR- and HER2+ (i.e., HER2-enriched); ER-, PR- and HER2- (i.e., triple negative, TN).

RESULTS

More patients with MBC were ≤40 years at the time of breast cancer diagnosis than patients with SBC (34.6% vs. 19.3%, P < 0.01). The proportion of subtypes in SBC and MBC were as follows: luminalA, 65.8% vs. 45.0%; luminalB, HER2+, 9.0% vs. 8.5%; HER2-enriched, 4.1% vs. 12.1%; and TN, 11.2% vs. 31.2%, respectively (P < 0.01). The 10-year overall survival rate in patients with SBC and MBC was 89.0% and 93.6%, respectively. The 10-year disease-free survival rate in patients with SBC and MBC was 79.6% and 80.9%, respectively. Locoregional recurrence was found in 2.5% of patients with SBC and 9.9% of patients with MBC. Distant metastasis occurred in 8.7% of patients with SBC and 4.9% of patients with MBC.

CONCLUSION

The distribution of breast cancer subtypes was different between SBC and MBC. TN-subtype was profoundly more frequent in MBC whereas luminal-subtype was most frequently found among SBC.

Association between metabolic syndrome and prognosis of breast cancer: a meta-analysis of follow-up studies

BACKGROUND

Metabolic syndrome (MetS) has been suggested to be a risk factor for many cancers, including breast cancer. However, it remains unclear whether MetS predicts poor prognosis in women with breast cancer. A meta-analysis was performed to summarize the association between MetS and clinical outcome in women with breast cancer.

METHODS

Cohort studies were identified by search of PubMed and Embase databases. A random-effect model incorporating the potential heterogeneity was applied to pool the results. Subgroup analyses according to the ethnicity and study design were performed.

RESULTS

Nine cohort studies with 17,892 women with breast cancer were included. Pooled results showed that MetS was significantly associated with an increased risk of breast cancer recurrence (adjusted risk ratio [RR] = 1.52, 95%, p = 0.02). Subgroup analyses showed that MetS was independently associated with increased recurrence of breast cancer in Caucasians (adjusted RR = 1.75, p = 0.02), but not in Asians (adjusted RR = 1.07, p = 0.81), and MetS was associated with a trend of increased risk of breast cancer recurrence in both the prospective and retrospective studies. Although we failed to show a significant association between MetS and breast cancer related deaths (adjusted RR = 1.24, p = 0.41), MetS was associated with increased risk of all-cause deaths in these patients (adjusted RR = 1.80, p < 0.001).

CONCLUSIONS

MetS may predict the risk of cancer recurrence and mortality in women with breast cancer, particularly in Caucasians.

Race and risk of subsequent aggressive breast cancer following ductal carcinoma in situ

BACKGROUND

General populations of black women have a higher risk of developing breast cancer negative for both estrogen receptor (ER) and progesterone receptor (PR) in comparison with white counterparts. Racial differences remain unknown in the risk of developing aggressive invasive breast cancer (IBC) that is characterized by negativity for both ER and PR (ER-PR-) or higher 21-gene recurrence scores after ductal carcinoma in situ (DCIS).

METHODS

This study identified 163,892 women (10.5% black, 9.8% Asian, and 8.6% Hispanic) with incident DCIS between 1990 and 2015 from the Surveillance, Epidemiology, and End Results data sets. Cox proportional hazards regression was used to estimate hazards ratios (HRs) of subsequent IBC classified by the hormone receptor status and 21-gene recurrence scores.

RESULTS

During a median follow-up of 90 months, 8333 women developed IBC. In comparison with white women, the adjusted HR of subsequent ER-PR- breast cancer was 1.86 (95% confidence interval [CI], 1.57-2.20) for black women (absolute 10-year difference, 2.2%) and 1.40 (95% CI, 1.14-1.71) for Asian women (absolute 10-year difference, 0.4%); this was stronger than the associations for ER+ and/or PR+ subtypes (Pheterogeneity  = .0004). The 21-gene recurrence scores of subsequent early-stage, ER+ IBCs varied by race/ethnicity (Pheterogeneity  = .057); black women were more likely than white women to have a recurrence score of 26 or higher (HR, 1.38; 95% CI, 1.00-1.92). No significant difference was observed in the risks of subsequent IBC subtypes for Hispanic women.

CONCLUSIONS

Black and Asian women with DCIS had higher risks of developing biologically aggressive IBC than white counterparts. This should be considered in treatment decisions for black and Asian patients with DCIS.

Promoting bone health management in women diagnosed with breast cancer: a pilot randomized controlled trial

This study investigates, in women diagnosed with breast cancer, the feasibility of evaluating the effects of educational material and its delivery method, on bone health management. The study results suggest educational material may improve rates of bone mineral density testing.

INTRODUCTION

Educational materials improve bone mineral density (BMD) testing rates in high-risk patients, but the effect is unknown in women diagnosed with breast cancer. Methods of delivering educational materials may also affect testing rates. The purposes of this study were to determine the feasibility of the protocol and to pilot-test the effects of educational material and its delivery methods on BMD testing rates.

METHOD

Pilot randomized controlled trial with block randomization. Fifty-four women (aged 65-75 and diagnosed with breast cancer ≥ 3 years ago (2010-2012) and not taking osteoporosis medication) were recruited from February to May 2016 and randomized to three groups: control without educational material, educational material delivered by postal mail, and educational material delivered by patient choice of postal mail, email, or text messaging. Outcome measures were primarily evaluated using self-report questionnaires.

RESULTS

The participation rate, defined as the proportion of eligible participants who consented to participate, was 39.1%. Primary outcome measure was obtained for 98% of the recruited women. During the 6-month follow-up period, BMD testing rates were significantly higher in the groups receiving educational materials by mail (26%, 95%CI = 10 to 49) and by patient choice (18%, 95%CI = 5 to 41), when compared with the control group (6%, 95%CI = 0.3 to 25). Educational material was associated with a 17% higher BMD testing rate.

CONCLUSIONS

The study protocol is feasible for a large-scale study. The educational material intervention is broadly accepted by the study participants with a promising positive effect on BMD testing rates.

Immunohistochemistry defined subtypes of breast cancer in 678 Sudanese and Eritrean women; hospitals based case series

BACKGROUND

Breast cancer is the most common malignancy accounting for 25% of all cancers in females. In Africa, breast cancer prevalence and mortality are steadily increasing. Knowledge of hormone receptors and human epidermal growth factor receptor-2 (HER-2) expressions are vital for breast cancer management plans and decision making. There is wide regional variation in the proportion of these biomarkers, especially in African countries. Hormone receptors positivity in indigenous African and African American women is considered to be low and triple negative breast cancer is a dominant phenotype. There is paucity of data regarding hormone receptors (ER and PR) and HER2 expressions in North-eastern Africa (Eritrea and Sudan). The purpose of this study was to evaluate the expression of ER, PR and HER2 in Eritrean and Sudanese case series and correlate these biomarkers with the clinicopathological profile.

METHOD

Clinicopathologic data of patients were collected from clinical records. Immunohistochemistry biomarkers (ER, PR, and HER2) were assessed in consecutive female patients who had been diagnosed with invasive breast cancer from 2011 to 2015 in Gezira University Pathology Laboratory, the Sudan and National Health laboratory, Asmara, Eritrea.

RESULTS

There were 678 cases involved in this study. The mean age was 48.8 years with ±0.53 standard error of the mean. Two-thirds of the case were ≤50 years. Invasive ductal carcinoma, no special type was the most dominant histologic type (86%) in both study groups. The majority of cases (70%) had tumour stage pT2 and pT3 and about 50% had lymph node involvement. Less than 5% of the cases had well-differentiated tumours. The ER, PR and HER2 positive rates were 45%, 32%, and 29%, respectively. The proportion of luminal-A like, luminal-B like, HER2 enriched and TNBC were 37%, 13%, 16% and 34%, respectively. Fisher extract analysis showed age (p = .015), tumour size (p = .041), and histologic grade (p = .000) were significantly associated with intrinsic subtypes. Furthermore, Logistic regression analysis stratified by origin, age, tumour size, lymph-node metastasis and grade indicated that younger women age (≤50 years) and grade III tumours were more likely to be diagnosed with ER negative breast cancer.

CONCLUSION

Most of Sudanese and Eritrean women were diagnosed at younger age and with unfavourable prognostic clinicopathologic prognostic markers. TNBC is more frequent in this cohort study; patients with grade III tumours and young age are more likely to be hormone receptors negative. Therefore, routine determination of hormone receptors is warranted for appropriate targeted therapy.

Gastrin-releasing Peptide Receptor Imaging in Breast Cancer Using the Receptor Antagonist (68)Ga-RM2 And PET

Introduction: The gastrin-releasing peptide receptor (GRPR) is overexpressed in breast cancer. The present study evaluates GRPR imaging as a novel imaging modality in breast cancer by employing positron emission tomography (PET) and the GRPR antagonist ⁶⁸Ga-RM2.

Methods: Fifteen female patients with biopsy confirmed primary breast carcinoma (3 bilateral tumors; median clinical stage IIB) underwent ⁶⁸Ga-RM2-PET/CT for pretreatment staging. In vivo tumor uptake of ⁶⁸Ga-RM2 was correlated with estrogen (ER) and progesterone (PR) receptor expression, HER2/neu status and MIB-1 proliferation index in breast core biopsy specimens.

Results: 13/18 tumors demonstrated strongly increased ⁶⁸Ga-RM2 uptake compared to normal breast tissue (defined as PET-positive). All PET-positive primary tumors were ER- and PR-positive (13/13) in contrast to only 1/5 PET-negative tumors. Mean SUV_MAX of ER-positive tumors was 10.6±6.0 compared to 2.3±1.0 in ER-negative tumors (p=0.016). In a multivariate analysis including ER, PR, HER2/neu and MIB-1, only ER expression predicted ⁶⁸Ga-RM2 uptake (model: r²=0.55, p=0.025). Normal breast tissue showed inter- and intraindividually variable, moderate GRPR binding (SUV_MAX 2.3±1.0), while physiological uptake of other organs was considerably less except pancreas. Of note, ⁶⁸Ga-RM2-PET/CT detected internal mammary lymph nodes with high ⁶⁸Ga-RM2 uptake (n=8), a contralateral axillary lymph node metastasis (verified by biopsy) and bone metastases (n=1; not detected by bone scan and CT).

Conclusion: Our study demonstrates that ⁶⁸Ga-RM2-PET/CT is a promising imaging method in ER-positive breast cancer. In vivo GRPR binding assessed by ⁶⁸Ga-RM2-PET/CT correlated with ER expression in primary tumors of untreated patients.

Operation with less adjuvant therapy for elderly breast cancer

BACKGROUND

The standard of care for elderly women with breast cancer remains controversial. The aim of this study was to clarify the management of elderly breast cancer patients who undergo surgery.

MATERIALS AND METHODS

This retrospective single-center cohort study included 2276 breast cancer patients who underwent surgery between 1993 and 2014. The patients were divided into three groups according to age: ≤64 y (young), 65-74 y (older), and ≥75 y (elderly).

RESULTS

The elderly had more advanced stage disease at diagnosis (stage III and IV, 16.2%, 17.5%, and 22.1% for the young, older, and elderly groups, respectively). The elderly were more likely to undergo mastectomy (43.3%, 41.4%, and 50.7%, respectively), omit axillary operation (0.6%, 1.1%, and 9.3%, respectively), and skip radiotherapy after breast-conserving surgery (93.1%, 86.8%, and 29.1%, respectively). Endocrine therapy was widely used in all the groups (94.4%, 93.8%, and 90.1%, respectively), but frequency of chemotherapy was lower in the elderly regardless of hormone receptor (HR) status (40.8%, 25.5%, and 9.3% in HR(+), 87.2%, 75.3%, and 39.5% in HR(-), respectively). Although the locoregional recurrence rate was higher in the elderly (4.2%, 3.4%, and 7.0% at 5 y, respectively; P = 0.028), there were no differences among groups in distant metastasis-free survival or breast cancer-specific survival.

CONCLUSIONS

Although elderly patients had more advanced stages of cancer and received less treatment, there were no differences in survival. Omission of axillary dissection, radiation, and chemotherapy after operation may be an option for breast cancer patients aged ≥75 y.