Breast cancer molecular subtypes and receptor status among women at Potchefstroom Hospital: a cross-sectional study

Abstract

Introduction this study aimed to determine the prevalence of receptor status and molecular subtypes in women with breast cancer treated at Potchefstroom Regional Hospital, South Africa and to analyze the association of molecular subtypes with some clinicopathologic characteristics of the tumor. Methods the study population for this cross-sectional study consisted of 116 women with primary invasive breast cancer, treated at the hospital from 1 st January 2012 to 31 st December 2018. Molecular subtypes were classified by immunohistochemical surrogates as luminal A (estrogen receptor (ER) positive and/or progesterone receptor (PR) positive, HER2-; Ki-67 <30%), luminal B HER2- (ER+ and/or PR+, HER2-; Ki-67 ≥30%), luminal B HER2+ (ER+ and/or PR+, HER2+; any Ki-67), HER2 enriched (ER- and PR-, HER2+; any Ki-67), or triple-negative (ER-, PR-, HER2-, any Ki-67). Results the proportions of breast cancer receptor status of ER+, PR+ and HER2-, were 71.6%, 64.7% and 75.9%, respectively. The molecular subtypes of 29.3% of patients were luminal A-type, 24.1% were luminal B HER2-, 22.4% were triple-negative, 18.1% were luminal B HER2+ and 6% were HER2-enriched. Molecular subtypes were significantly associated with tumor grade (p <0.001; Cramér's V=0.337), but independent of age (p=0.847), menopausal status (p=0.690), histology type (p=0.316), cancer stage (p=0.819), lymph node status (p=0.362), or tumor size (p=0.255). Conclusion the study has revealed that most of the breast cancer in our setting was receptor-positive; approximately one-quarter were triple-negative. Furthermore, the study showed that luminal type A and B are the preponderant molecular subtypes. Molecular subtypes were associated with tumor grade but independent of age and menopausal status. The current study may assist in guiding the therapeutic strategy for patients with breast cancer in the Potchefstroom hospital catchment area.

TRIM39 is a poor prognostic factor for patients with estrogen receptor‐positive breast cancer and promotes cell cycle progression

“…The luminal A‐like subtype was defined as ER and/or PgR positive, HER2 negative and low Ki67 (<30%). The luminal B‐like subtype was defined as ER and/or PgR positive, HER2 negative and high Ki67 (≥30%), or ER and/or PgR positive and HER2 positive 25,26 …”

Delineating intra-tumoral heterogeneity and tumor evolution in breast cancer using precision-based approaches

“…Despite this limitation, studies attempting to understand the immunohistochemical landscape of breast cancer illustrate that a larger proportion of cases present at a more advanced stage in younger, pre-menopausal patients ( Jedy-Agba et al, 2016 ; Azubuike et al, 2018 ). Although estrogen receptor-positive (ER+) breast cancer remains a dominant phenotype in Africa ( Kakudji et al, 2021 ; Popli et al, 2021 ), a substantive increase in other subtypes, particularly triple-negative breast cancer or basal-like tumors in Uganda ( Galukande et al, 2014 ), Eritrea and Sudan ( Sengal et al, 2017 ), has been found compared to developed countries ( Sung et al, 2021 ; Hercules et al, 2022 ). Moreover, triple-negative breast cancer frequency is high in Caribbean and North American populations with West African ancestry, indicating a heritable factor that has yet to be fully delineated ( Hercules et al, 2022 ).…”

Pharmacogenetics of Breast Cancer Treatments: A Sub-Saharan Africa Perspective

“… 20 Other studies show a prevalence of ER+ breast cancer between 58% and 64% in South Africa. 21 These subtypes have been associated with different prognoses, with patients with luminal A tumours having the best prognosis, and patients with triple negative subtype (ER-/PR-/HER2-) having the worst prognosis 22 ( Table 1 ). However, a significant minority of patients relapse despite adjuvant anti-estrogen therapy, with most patients with metastatic disease ultimately developing resistance to anti-estrogen therapies.…”