WASHINGTON — For women who carry a notorious cancer gene, surgery to remove healthy ovaries is one of the most protective steps they can take. New research suggests some may benefit most from having the operation as young as 35.
Women who inherit either of two faulty BRCA genes are at much higher risk of developing breast and ovarian cancer than other women, and at younger ages. Actress Angelina Jolie generated headlines last year when she had her healthy breasts removed to reduce her cancer risk.
Monday’s study is the largest yet to show the power of preventive ovarian surgery for those women. The study estimated it can reduce women’s risk of death before age 70 from cervical or breast cancer by 77 percent.
Ovarian cancer is particularly deadly, and there is no effective way to detect it early like there is for breast cancer. So for years, doctors have advised BRCA carriers to have their ovaries removed between the ages of 35 and 40, or when women are finished having children.
The new study suggests the surgery, called an oophorectomy, should be timed differently for the different genes. The research was published in the Journal of Clinical Oncology.
For women who carry the higher-risk BRCA1, the chance of already having ovarian cancer rose from 1.5 percent at age 35 to 4 percent at age 40, said lead researcher Dr. Steven Narod of the University of Toronto. After that, the risk jumped to 14 percent by age 50.
In contrast, the researchers said carriers of the related BRCA2 gene could safely delay surgery into their 40s. The study found only one case in a woman younger than 50.
Ovarian surgery ‘‘is the cornerstone for cancer prevention,’’ Narod said. ‘‘The typical woman with a BRCA1 mutation will benefit to a large extent from an oophorectomy at age 35, and we want to make that a pretty standard recommendation.’’
Future studies would have to verify the findings, and other specialists urged caution.
Waiting until age 40 for ovary removal, as many women with BRCA1 do today, makes a very small difference, stressed Dr. Claudine Isaacs, an oncologist and cancer risk specialist at Georgetown University’s Lombardi Comprehensive Cancer Center, who wasn’t involved in the new research.
The findings shouldn’t frighten women into acting sooner if they’re not ready, agreed Dr. Susan Domchek of the University of Pennsylvania’s Basser Research Center for BRCA, who also wasn’t involved in the study.
Many women have babies during their late 30s, and ovary removal sends women into early menopause that can increase their risk of bone-thinning osteoporosis or heart disease later.
‘‘Thirty-five isn’t necessarily a magic number,’’ Domchek said. ‘‘If you are talking to a woman who hasn’t yet finished having her kids, it’s a completely reasonable thing to discuss the low risk of ovarian cancer by age 40 in the context of the other decisions that she’s making in her life.’’