Breast cancer: Do you really need BRCA tests?
Dr Rajas Patel
Roughly 80 per cent of all breast cancers are described as ER-positive which means that they grow in response to the hormone called oestrogen. About 65 per cent of breast cancers are PR-positive, growing in response to another hormone named progesterone.
In 2015, American actress Angelina Jolie made headlines with her announcement of having her ovaries and both breasts removed as a preventative measure to reduce her risk for cancer.
At the time, Jolie revealed she carried a mutation in the BRCA1 gene that came with an 87 per cent risk of breast cancer and a 50 per cent risk of ovarian cancer. With this declaration, Jolie inspired several discussions about a lesser-known aspect of cancer, namely the role of these genetic mutations. And, in India, where breast cancer is the most common cancer among women and the age for the onset of breast and ovarian cancer is a decade younger than other countries, understanding the role of BRCA genes is more important than ever before.
The major reason for low survival rates of breast cancer in India is that the awareness about cancer and its treatment is very low. The normal screening of breast cancer in Indian women is very low.
Understanding breast cancer
Roughly 80 per cent of all breast cancers are described as ER-positive, which means that they grow in response to the hormone called oestrogen. About 65 per cent of breast cancers are PR-positive, growing in response to another hormone named progesterone. If the cancerous mass has a significant number of receptors for either oestrogen or progesterone, it is considered hormone-receptor positive. On the other hand, approximately 20 per cent of breast cancers are marked by the presence of HER2 receptors on cancer cells. These cancers are often aggressive and fast-growing. Women diagnosed with breast cancer are commonly tested for ER, PR and HER2 receptors, in order to accurately diagnose and treat their ailment.
The role of BRCA testing
BRCA genes act as tumour suppressors by preventing cells from growing indiscriminately and becoming cancerous. Mutations in BRCA1 and BRCA2 genes could, therefore, potentially increase the likelihood of tumours. Over the last decade, it has been observed that women who have been diagnosed with breast cancer below the age of 50 and have tested negatively for ER, PR and HER2 receptors are more likely to BRCA1 or BRCA2 positive. Simply put, such women are at an increased risk for developing a second malignancy in their ovaries.
Further, even after such women have undergone surgery and chemotherapy for ovarian cancer, they tend to relapse earlier than other patients. In cases where the ovarian cancer returns within six months of the last chemo cycle, the disease is termed as drug-resistant and is much harder to treat. There is also a 25-50 percent chance that their children will also be BRCA1 and BRCA2 positive and will be at a higher risk of developing cancer at an earlier age. In men, BRCA gene mutations increase the chances of pancreatic, prostrate and male breast cancer.
In recent years, BRCA testing has been declared as essential for every woman diagnosed with breast and ovarian cancer. BRCA tests are simple blood tests that are offered by several laboratories in major metro cities in India. Understand, however, that this is an advanced test that calls for specialised equipment and knowhow – follow your doctor’s recommendations for laboratories that specialise in oncology tests or reputed laboratories that have proven expertise in BRCA testing.
The author is medical oncologist, RH Onco Clinic, Navi Mumbai