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

Abstract

Purpose: Different biological characteristics, therapeutic responses, and diseasespecific outcomes are associated with different molecular subtypes of breast cancer (BC). Although there have been different studies on BC in the Ethiopian capital city of Addis Ababa, there have been few studies in other parts of the nation, and none have evaluated biological characteristics in other locations in the context of the extensive ethnic and genetic diversity found in Ethiopia. This study was carried out to evaluate the distribution of immunohistochemistry (IHC) subtypes of BCs throughout four Ethiopian regions. Methods: A total of 227 formalin-fixed paraffin-embedded (FFPE) tissue blocks were collected from tertiary hospitals in four Ethiopian regions between 2015 and 2021. The IHC staining was performed for subtyping, ER, PR, HER2, and Ki-67 proliferation markers. Frontiers in Endocrinology 01 frontiersin.org OPEN ACCESS EDITED BY Shahin Sayed, Aga Khan University Hospital, Kenya REVIEWED BY Sallie Schneider, Baystate Medical Center, United States Dana Carmen Zaha, University of Oradea, Romania Tjokorda Gde Bagus Mahadewa, Udayana University, Indonesia *CORRESPONDENCE Esmael Besufikad Belachew getbb2006@gmail.com †These authors have contributed equally to this work RECEIVED 29 June 2023 ACCEPTED 20 October 2023 PUBLISHED 09 November 2023 CITATION Belachew EB, Desta AF, Gebremariam TY, Deneke DB, Ashenafi S, Yeshi MM, Fenta BD, Alem AT/H, Alemu A, Abafogi AK, Desta T, Chanyalew M, Beshah D, Taylor L, Bauer M, Tsehay D, Girma S, Melka DS, Tessema TS, Kantelhardt EJ and Howe R (2023) Immunohistochemistry-derived subtypes of breast cancer distribution in four regions of Ethiopia. Front. Endocrinol. 14:1250189. doi: 10.3389/fendo.2023.1250189 COPYRIGHT © 2023 Belachew, Desta, Gebremariam, Deneke, Ashenafi, Yeshi, Fenta, Alem, Alemu, Abafogi, Desta, Chanyalew, Beshah, Taylor, Bauer, Tsehay, Girma, Melka, Tessema, Kantelhardt and Howe. This is an openaccess article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Original Research PUBLISHED 09 November 2023 DOI 10.3389/fendo.2023.1250189 Results: The mean age at diagnosis was 43.9 years. The percentage of ER and PR-negative tumors were 48.3% and 53.2%, respectively. The IHC subtypes showed the following distribution: 33.1% triple-negative breast cancer (TNBC), 27.6% luminal B, 25.2% luminal A, and 14.1% HER2 enriched. In multiple logistic regression analysis, grade III and HER2 positivity were associated with larger tumor size, and also originating from Jimma compared to Mekele. Conclusion: Patients with ER-negative, PR-negative, and TNBC were found in 48.3%, 53.2%, and 33.1% of cases, respectively, showing that half the patients could potentially benefit from endocrine treatment. A considerably high prevalence of TNBC was reported in our study, demanding additional research that includes genetic predisposition factors. Additionally, aggressive tumors were found in a high percentage of younger age groups, which must be considered when planning personalized treatment strategies.