Ovarian Cancer Gene and Early Removal of Ovaries
In particular, women with BRCA1 mutation should have surgery by age 35, researchers say
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.
In total, having the ovaries removed reduced the risk of death from any cause by 77 percent. The majority of this reduction comes from the reduced risk of ovarian, fallopian tube, peritoneal and breast cancers, the researchers explained.
In a previous study, Narod's group found that removing the ovaries also reduced the risk of breast cancer by 48 percent in women with a BRCA1 mutation, and the risk of dying from breast cancer by 70 percent in women diagnosed with the disease, according to an American Society of Clinical Oncology news release.
Dr. Andrew Menzin, the associate chief of gynecologic oncology at North Shore-LIJ Cancer Institute in Manhasset, N.Y., said the new study "provides strong support for this intervention and can help people decide, in the context of their lives, what to do."
Menzin, who was not involved with the study, said that women with a family history of breast or ovarian cancer should be screened by their primary care doctor.
Since genetic testing has not only medical but also other implications -- such as the anxiety it can cause -- it should only be done along with genetic counseling to interpret the results, he noted. "It's a combination of the science of medicine and the art of medicine," he said.