Breast cancer is the most common cancer in South African women and will affect one in every 33 women in the country.
According to Stellenbosch University geneticist Prof Maritha Kotze, about 15 percent of all cancers including those affecting the breasts are inherited. Just two genes, known as BRCA1 and 2, are responsible for most hereditary breast cancers.
In 2013, genetic testing revealed that Jolie carried the BRCA1 gene. Having recently lost her own mother to cancer, the star opted to have a preventative double mastectomy in an attempt to avoid developing breast cancer.
New research presented on Tuesday at the Cancer Association of South Africa’s (CANSA) Research in Action Conference in Stellenbosch has shown that these potentially killer genes may be more predominant among Afrikaner cancer patients.
According to the research, 67 percent of Afrikaans breast cancer patients from high-risk families that were surveyed, were found to carry at least one of the genes. Meanwhile, BRCA-related cancers only accounted for eight percent of breast cancers among black women, according to Lizette Jansen van Rensburg, a professor in Genetics at the University of Pretoria.
According to the latest available data from the National Cancer Registry dating back to 2009, Asian women have the highest risk of developing breast cancer, closely followed by white and then coloured women. According to the data, black women have the lowest breast cancer risk.
New research may also indicate that genes not only play an important role in whether a woman will develop breast cancer or not, but also impacts on what treatment will have the best outcome. This may open up the field of personalised treatment in South Africa.
Kotze’s research has shown that cancers caused by different genes may respond differently to different types of therapy, making it possible to customize treatment for patients, based on advanced micro array technology and next-generation sequencing.
A web portal (www.gknowmix.com) was developed with the support of the Medical Research Council to assist patients and doctors to identify genetic testing most likely to benefit patients’ treatment outcomes.
“We strive towards one day providing each patient with a drug targeted specifically at their tumour’s genetics,” said Kotze.
Image: x-ray of the breast, Shutterstock