Ovarian Cancer Gene and Early Removal of Ovaries
In particular, women with BRCA1 mutation should have surgery by age 35, researchers say
Narod's team is currently running pilot programs in Iceland and Bermuda testing every woman who has a mammogram for BRCA mutations as well.
Ovarian cancer is often called the "silent killer" because symptoms may not appear until the cancer had spread. In 2013, the U.S. National Cancer Institute estimated that 22,240 women would be diagnosed with the disease that year and 14,030 would die from it.
This is why in the United States, as many as 70 percent of women who know they carry BRCA mutations choose to have their ovaries removed, the researchers noted.
The report was published Feb. 24 in the Journal of Clinical Oncology.
For the study, researchers from North America and Europe used an international registry to identify 5,783 women who carried mutations of the BRCA genes.
Among these women, 2,270 did not have their ovaries removed. Another 2,123 had already had the surgery at the start of the study, and 1,390 women had surgery during the study follow-up period from 1995 to 2011.
During an average follow-up of 5.6 years, 186 women developed either ovarian cancer, fallopian tube cancer or peritoneal cancer (cancer of the abdominal lining that covers the uterus), the researchers found.
Narod's group reported that women who had their ovaries removed reduced their risk of ovarian cancer by 80 percent. Among women with a BRCA1 mutation, delaying the surgery until age 40 increased the risk of ovarian cancer by 4 percent and the risk increased 14.2 percent if a woman waited until age 50 before having the operation.
For women with the BRCA2 mutation alone, however, the risk of developing ovarian cancer was very low. Among such women in the study, only one developed ovarian cancer.
The researchers noted that the lifetime risk of ovarian cancer among all women -- including those without BRCA mutations -- is only 1.4 percent.
During the study, 511 women died: 333 died of breast cancer, 68 from ovarian, fallopian tube or peritoneal cancers, and the rest from other causes.