Breast Cancer Phenotypes in Africa: A Scoping Review and Meta-Analysis

Abstract

PURPOSE Africans have been associated with more aggressive forms of breast cancer (BC). However, there is a lack of data regarding the incidence and distribution of different subtypes on the basis of phenotypic classification. This scoping review and meta-analysis was undertaken to determine the distribution pattern of BC phenotypes (luminal, human epidermal growth factor receptor 2 [HER2]+, and triple-negative breast cancer [TNBC]) across the African region. METHODS Four online databases (PubMed, Scopus, ProQuest, and EBSCOhost) were accessed to identify studies published between 2000 and 2022 reporting the representation of receptor status (estrogen receptor, progesterone receptor, and HER2) in African patients with BC. Furthermore, the meta-analysis was carried out using a random-effects model and pooled using the inverse variance method and logit transformation. 95% CI and I2 statistics were calculated using the Clopper-Pearson method to estimate between-study heterogeneity. RESULTS A total of 2,734 records were retrieved, of which 2,133 were retained for further screening. After the screening, 63 studies were finally selected for the scoping review and meta-analysis. The pooled frequency of luminal, HER2-positive (HER2+), and TNBC was estimated at 56.30%, 12.61%, and 28.10%, respectively. Northern Africa had the highest frequency of the luminal subtype, while West Africa showed higher frequencies of HER2+ and TNBC subtypes. The review also had a representation of only 24 countries in Africa. CONCLUSION Our results highlight the disparity in the representation of molecular subtypes among the people in different regions of Africa. There is a need to incorporate routine molecular subtyping into the management of African patients with BC.

Breast Cancer Survival in Sub-Saharan Africa—Diversity Across Disparities

“…In West Africa, the prevalence of the aggressive triple-negative breast cancer subtype reaches greater than 40%. 9 Southern Africa has the world's largest population of women living with comorbid breast cancer and HIV, a group who experience nearly a 50% increase in mortality compared with other patients with breast cancer. 10 Unfortunately, the data from most of the individual studies included in this review are insufficient to describe the relative contribution of each of these factors.…”

“…Beyond these 3 essential contributors, SSA has regionally specific challenges as well. In West Africa, the prevalence of the aggressive triple-negative breast cancer subtype reaches greater than 40% . Southern Africa has the world’s largest population of women living with comorbid breast cancer and HIV, a group who experience nearly a 50% increase in mortality compared with other patients with breast cancer .…”