Ethiopian breast cancer tissue study links immune-cell infiltration to subtype and grade

An immunohistochemical analysis of 81 Ethiopian breast cancer tissue samples found higher levels of several immune-cell and immune-marker measures in non-luminal tumors and in higher-grade disease. According to the study abstract, triple-negative and HER2-positive breast cancers had greater proportions of stromal CD20-positive tumor-infiltrating lymphocytes, intratumoral CD3-positive tumor-infiltrating lymphocytes and CD68-positive tumor-associated macrophages than luminal subtypes.

The researchers analyzed formalin-fixed, paraffin-embedded breast cancer tissue blocks using immunohistochemistry to assess tumor-infiltrating lymphocytes, tumor-associated macrophages and programmed death ligand 1, or PD-L1. Statistical analyses were conducted with R version 4.4.2. The study was designed to characterize immune features of the tumor microenvironment in breast cancer samples from Ethiopia and evaluate the tumors’ reported immunogenicity.

Immune-cell measures differed by tumor grade. Compared with grade I and II cancers, grade III breast cancers showed significantly higher stromal PD-L1 expression, intratumoral PD-L1 expression, intratumoral CD3-positive tumor-infiltrating lymphocytes and intratumoral CD163-positive tumor-associated macrophages. The reported p-values were 0.024, 0.025, 0.023 and 0.015, respectively. For the non-luminal versus luminal subtype comparison, the abstract reported p-values of 0.023 for stromal CD20-positive lymphocytes, 0.0075 for intratumoral CD3-positive lymphocytes and 0.037 for CD68-positive macrophages.

The abstract concludes that infiltrating immune cells were more common in hormone receptor-negative and higher-grade breast cancers, which the authors described as consistent with findings from resource-rich countries. The available evidence is limited to an abstract of a tissue-based observational analysis, so it does not establish whether the measured immune profiles affected survival, treatment response or clinical outcomes. The sample comprised 81 Ethiopian breast cancer specimens, and the abstract provides no information about longitudinal follow-up, patient selection, subtype distribution or statistical adjustment for potential confounders. Accordingly, the findings describe associations within the analyzed sample rather than causal effects or validated predictors for patient care.

Subject of Research: Tumor-microenvironment immune profiling of Ethiopian breast cancer by subtype and grade

Article Title: Immunohistochemical profiling of the tumor microenvironment in Ethiopian breast cancer tissue: insights into pathology and subtypes

Article References: Belachew, E. B., Desta, A. F., Sewasew, D. T., Bauer, M., Nigussie, B., Hassen, M., Yeshi, M. M., Alem, A. T., Yimam, S., Getachew, B., Girma, S., Kantelhardt, E. J., Tessema, T. S., & Howe, R. C. (2026). Immunohistochemical profiling of the tumor microenvironment in Ethiopian breast cancer tissue: insights into pathology and subtypes. BMC Cancer. https://doi.org/10.1186/s12885-026-16995-z

Image Credits: AI Generated

DOI: 10.1186/s12885-026-16995-z

Keywords: breast cancer, Ethiopia, tumor microenvironment, immunohistochemistry, tumor-infiltrating lymphocytes, tumor-associated macrophages, PD-L1, triple-negative breast cancer, HER2-positive breast cancer, tumor grade, Immunohistochemical, profiling