Intrinsic subtypes in Ethiopian breast cancer patient

Abstract

Purpose The recent development of multi-gene assays for gene expression profiling has contributed significantly to the understanding of the clinically and biologically heterogeneous breast cancer (BC) disease. PAM50 is one of these assays used to stratify BC patients and individualize treatment. The present study was conducted to characterize PAM50-based intrinsic subtypes among Ethiopian BC patients. Patients and methods Formalin-fixed paraffin-embedded tissues were collected from 334 BC patients who attended five different Ethiopian health facilities. All samples were assessed using the PAM50 algorithm for intrinsic subtyping. Results The tumor samples were classified into PAM50 intrinsic subtypes as follows: 104 samples (31.1%) were luminal A, 91 samples (27.2%) were luminal B, 62 samples (18.6%) were HER2-enriched and 77 samples (23.1%) were basal-like. The intrinsic subtypes were found to be associated with clinical and histopathological parameters such as steroid hormone receptor status, HER2 status, Ki-67 proliferation index and tumor differentiation, but not with age, tumor size or histological type. An immunohistochemistry-based classification of tumors (IHC groups) was found to correlate with intrinsic subtypes. Conclusion The distribution of the intrinsic subtypes confirms previous immunohistochemistry-based studies from Ethiopia showing potentially endocrine-sensitive tumors in more than half of the patients. Health workers in primary or secondary level health care facilities can be trained to offer endocrine therapy to improve breast cancer care. Additionally, the findings indicate that PAM50-based classification offers a robust method for the molecular classification of tumors in the Ethiopian context.

Immunohistochemistry-derived subtypes of breast cancer distribution in four regions of Ethiopia

“…Additionally, they are resistant to endocrine-and HER2-targeted therapies (55). A higher percentage of TNBC subtypes (33.1%) was reported in this study, with the highest percentage in southwest Ethiopia (Jimma) (37.5%), followed by north Ethiopia (Mekelle) (36.4%), which is higher than the 23% (21,56) and 24.8% (18) reported in earlier Ethiopian studies from the capital city. TNBC subtypes were found on average in 26.4% of patients from African countries, with 22.8% in East Africa, 14.9% in Middle Africa, 22.6% in North Africa, and 16.6% in South Africa.…”

“How can a woman live without having a breast?”: challenges related to mastectomy in Ethiopia

“…Not having an alternative modified treatment in LMICs is one of the missed opportunities to address those elderly patients who want to optimise all medical treatments except the surgery. Given considerably lower toxicity and relative ease of administering oral therapies in comparison with other systemic treatments, pET can be considered an effective approach in LMICs [ 1 ], particularly in a country like Ethiopia where radiation treatment is limited and more than 65% of breast cancer tumours are ER positive [ 35 ].…”

Building Pathology Capacity in Sub-Saharan Africa to Improve Breast Cancer Diagnosis and Treatment: Training Laboratory Technicians in High-quality Manual Immunohistochemistry

“…Understanding the true distribution of breast cancer phenotypes among populations would help with allocation of resources associated with treatment (chemotherapy, endocrine therapy) and anticipated costs, human resources, and equipment. In settings with limited resources, prioritization of which reagents to purchase to perform IHC must account for the clinically useful and actionable information it will provide the clinician in making treatment decisions [11][12][13].…”