New Study Identifies Breast Cancer Genes Unique To Black Women In South Africa

A new study looks into breast cancer genes in Black South African women for the first time

New research has identified genetic variants associated with breast cancer in Black South African women.

Published in Nature Communications, the study identified two genetic variants tied to breast cancer, offering key insights into the disease’s genetic roots in African populations. It marks the first genome-wide association study (GWAS) of breast cancer conducted among African women living on the continent.

In the study, researchers at the Sydney Brenner Institute for Molecular Bioscience (SBIMB) identified consistent genetic patterns linked to breast cancer in Black South African women. They found genetic signals near the RAB27A gene, part of the RAS oncogene family, and USP22, a gene known for its high activity in breast cancer cells and association with poor outcomes.

“These genes have not been associated with the disease before, which is an important advance in understanding breast cancer risk and biology in women of African ancestry,” Dr. Mahtaab Hayat, the lead author of the study, said, according to Medical Express.

Until recently, most breast cancer genetics research centered on European and Asian populations, with limited focus on African ancestry, mainly African American women of West African descent. A DNA-based tool used to estimate lifetime cancer risk, known as the polygenic risk score (PRS), proved ineffective at identifying the difference between South African women with and without breast cancer.

“This is because most PRSs were developed in European populations, and their inaccuracy in African populations highlights the urgent need for ancestry-specific tools in cancer risk prediction,” said Dr. Jean-Tristan Brandenburg, also in the SBIMB and a lead author.

Breast cancer is the second most common cancer in South Africa and the leading cancer among women worldwide, with genetics playing a role in roughly 30% of cases. African populations possess the greatest genetic diversity in the world but remain significantly underrepresented in genomic research, limiting global understanding of disease risk and the development of effective tools and treatments.

“The study reveals that more people can benefit from genetic discoveries. It proves that new risk factors are still out there, waiting to be found,” Hayat said.