Women with a family history of breast cancer often want to get tested for the BRCA1 and BRCA2 genetic mutations linked to the disease.
But a new study suggests that even if a woman tests negative for the BRCA2 gene, she could still be at increased risk for breast cancer.
“With the recent revelation that Angelina Jolie tested positive for the BRCA gene, many patients have been asking questions regarding genetic testing,” said Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City. “The general public wants to know what a positive or negative test really means.”
Until now, it’s been thought that women in families with BRCA mutations who themselves test negative for the gene would have the same risk for breast cancer as women in the general population.
But that may not always be true, according the study, which was published November 27 in the journal Cancer Epidemiology, Biomarkers & Prevention.
The researchers analyzed data from more than 800 families in England with BRCA mutations. They found that 49 women in those families who tested negative for the family-specific BRCA mutation later went on to develop breast cancer.
Dr. Gareth Evans is an honorary professor of medical genetics and cancer epidemiology at the University of Manchester, in England.
“We found that women who test negative for family-specific BRCA2 mutations [still] have more than four times the risk for developing breast cancer than the general population,” Evans said in a journal news release.
“We also found that any increased risk for breast cancer is largely limited to BRCA2 families with strong family history and other genetic factors,” he said. “It is likely that these women inherit genetic factors other than BRCA-related genes that increase their breast cancer risk.”