Ovarian Cancer Patients with BRCA Mutations May Fare Better than Non-Carriers ► NCI Cancer Bulletin for January 24, 2012 - National Cancer Institute

NCI Cancer Bulletin for January 24, 2012 - National Cancer Institute

Ovarian Cancer Patients with BRCA Mutations May Fare Better than Non-Carriers

A large, multicenter study shows that women with ovarian cancer who have mutations in the BRCA1 or BRCA2 genes have better survival rates than women who do not have such mutations. The study is also the first to provide strong evidence that ovarian cancer prognosis is better for women with BRCA2 mutations than women with BRCA1 mutations. The results were published online today in JAMA.

Inherited mutations in BRCA1 and BRCA2 are the strongest known genetic risk factors for breast cancer and epithelial ovarian cancer, the most common form of ovarian cancer. These mutations are found in 6 to 15 percent of women with epithelial ovarian cancer; the relative prognosis for women who carry BRCA gene mutations compared with non-carriers has remained unclear due to differing study results.

“Because BRCA mutations are rare to begin with, and because ovarian cancer is also relatively uncommon, it’s hard to design studies that are big enough to provide definitive evidence on this question,” explained lead author Dr. Kelly Bolton, a UCLA medical student who is affiliated with the Laboratory of Translational Genomics in NCI’s Division of Cancer Epidemiology and Genetics.

Dr. Bolton and her colleagues combined data from 26 clinical research studies worldwide on the survival of women with ovarian cancer. This included data on 1,213 women with inherited BRCA1 or BRCA2 mutations and 2,666 women without these mutations. The women were followed for variable times between 1987 and 2010.

The research team’s analysis showed that the 5-year overall survival rate for ovarian cancer was 36 percent for non-carriers, 44 percent for BRCA1 mutation carriers, and 52 percent for BRCA2 mutation carriers. After adjusting for the stage and grade of a patient’s tumor at the time of diagnosis, as well as other factors that could affect prognosis, the researchers found that BRCA2 mutation carriers are twice as likely to survive than non-carriers in the 5 years following diagnosis, whereas BRCA1 mutation carriers have a 37 percent greater chance of survival in the 5 years following diagnosis than non-carriers.

“Our findings provide further support that BRCA1 and BRCA2 mutation carriers’ tumors are different biologically, and they should be treated separately,” said Dr. Bolton. “That’s really important for clinical trial design, especially if you’re studying drugs such as PARP inhibitors, which are being tested in BRCA1 and BRCA2 mutation carriers.”

The findings could eventually be used by clinicians when advising patients with ovarian cancer about their possible prognosis but further studies are needed, Dr. Bolton added.