BRCA genes not as deadly as supposed

A new study has revealed that breast cancer patients with BRCA mutations have equal chances of surviving the disease as their counterparts who don’t carry the inherited breast cancer genes.

The study, published in the July 12th issue of the New England Journal of Medicine, compared the survival rates of around 1500 Israeli women with BRCA1 or BRCA2 gene mutations to women without the genes. With no difference in the survival pattern of the two groups, the study rubbished previously established notions that BRCA breast cancer is more deadly than cancer without the inherited genes.

The BRCA gene belongs to a class of genes called tumour suppressors which regulates the cell cycle and prevents uncontrolled proliferation. It has been linked with an increased risk of breast cancer among carriers of the gene. Women with BRCA1 and 2 are at a higher risk of developing breast and ovarian cancer. The inherited genes account for 5% to 10% of all breast cancers diagnosed in the U.S and the lifetime risk of developing breast cancer is between three times and seven times higher for carriers than noncarriers, according to the National Cancer Institute. However, the new study has shown that the two genes have little to do with survival rates. The research also suggested that chemotherapy may be slightly more effective in carriers of the BRCA1 mutation.

“Women with mutations have a lot to deal with and they're always worried that their breast cancers when they are found will somehow be more lethal,” said Dr. Judy Garber of the Dana Farber Cancer Institute. She added, “The good news here is if you have breast cancer and a mutation, this is not necessarily the death sentence that you fear.”

The study was conducted among Israeli women because Israel has a very high concentration of Ashkenazi Jews. People of Ashkenazi Jewish descent are five times more likely to have inherited BRCA mutations than the general population. The researchers began by testing DNA from stored tumor specimens obtained from breast cancer patients treated in Israel in 1987 and 1988 in order to determine the incidence of BRCA mutations. The next step involved was reviewing the medical records of the women from whom the specimens were collected for a minimum of 10 years after diagnosis. BRCA1 or 2 mutations were indentified in 10% of the samples and the 10 year follow up revealed that the survival rates for both carriers and noncarriers were similar.

Researcher Gad Rennert said that the findings would reassure women who are at high risk for developing breast cancer because they carry a BRCA mutation. He added that classic predictors of poor outcome, such as tumor size at diagnosis and lymph node status, did not appear to impact survival among the women in the study.

“Most [BRCA carriers] who develop breast cancer will survive their disease.That is an important message to get out to women and their doctors.”, he said.