Ethnicity and characteristics of triple negative breast cancer (TNBC)

Document Type



Imaging and Diagnostic Radiology (East Africa)


Studies of the prevalence of hormone receptor status; ER/PR/HER2 in breast cancer from Sub Saharan Africa (SSA) are fraught with inconsistencies. There are multitude of reasons for these inconsistencies but the most prominent are inadequate breast biopsy material, small sample sizes, poor histopathology services and suboptimal handling of specimens. As an example, ER/PR/HER2 receptors for breast cancers are not part of the routine assessment for breast cancer and testing is only available in a couple of centers across the entire country. Variability in Radiology, Surgery and laboratory methodology and interpretation makes comparison between data difficult.

Available data shows a huge variability in the prevalence of TNBC within the sub-Saharan region. This is due to these factors and almost all suggest a much higher incidence of TNBC compared to the West. Core biopsy as a diagnostic tool is only available in academic or subspecialty hospital settings. Most diagnoses are based on tissue obtained by Fine Needle Aspiration (FNA). Given these constraints, making comparison between breast cancer data from the developed and developing world should be interpreted with caution.

As part of a larger funded study investigating the prevalence of Triple Negative Breast Cancer (TNBC) in Kenya, we organized a multidisciplinary workshop for participants from ten provincial health care facilities, all of whom are involved in providing breast cancer care. We sought to provide an overview of TNBC and importance of appropriate tissue collection and handling, identifying gaps in diagnostic processes, suggested remedial strategies and provided hands on training. We describe our experience, impact and outcome of this workshop.

Our aim was to accurately determine the histologic type and prevalence of ER/PR/HER2 using standardized methodology of ultrasound guided core biopsies. During the workshop, we trained Physicians how to perform core biopsies, thereafter store and transport biopsy samples.

Results: A total of 301 cases of breast cancer were included in the study.

Invasive ductal carcinoma (NOS) was the most common histologic type (84.2%). ER positivity was seen in 72.8%, PR in 64.8% and HER2 in 17.6% of all cases. Triple negative breast cancers (TNBC) constituted 20.2 % of the cases.

There was a significant association between receptor status and histologic grade (p<0.001) and statistically significant trend of increasing pathological stage of tumor (pT) associated with TNBC (p=0.020).

Conclusions: We present a definitive prospective analysis of IHC data from a single center and demonstrate that prevalence of ER/PR/HER2 receptor status from SSA is comparable with that in the West, which contradicts previous reports.

Publication (Name of Journal)

Ultrasound in Medicine & Biology