Ovary removal may improve breast cancer survival with gene mutation

Cancer cells. (iStock)

Women with a gene mutation that puts them at a high risk of breast and ovarian cancers have better survival odds if their ovaries and fallopian tubes are removed soon after a breast cancer diagnosis, suggests a new study from Canada.

Women with the BRCA1 gene mutation who were diagnosed with early-stage breast cancer and had salpingo-oophorectomy were 62% less likely to die from the cancer over more than a decade, compared to women who didn’t have the procedure.

“This is really providing evidence that it’s going to be effective and have influence on survival,” said Kelly Metcalfe, the study’s lead author from the Women’s College Research Institute in Toronto.

Women with the BRCA1 and BRCA2 gene mutations have up to a 70% risk of developing breast cancer during their lifetimes, the researchers point out online April 23 in JAMA Oncology. They’re also at an increased risk of ovarian cancer.

Past studies have found that removing the ovaries and tubes after a breast cancer diagnosis reduced the risk of death for women with the gene mutations, but those studies were small or didn’t look at the specifics of the cancers, the authors note.

For the new study, they compared data on 676 women with BRCA1 or BRCA2 mutations, who were age 65 or younger and diagnosed with breast cancer between 1977 and 2009. The average age at diagnosis was 42.

The women were tracked for periods ranging from less than one year, to 20 years. During that time, about 19% of the women died of their cancer.

The researchers compared 345 women who had their ovaries removed to 331 who did not.

Removing the ovaries was tied to an overall 62% reduced risk of death from the cancer over about 13 years. The apparent benefits were greatest when the removal was done soon after cancer diagnosis.

When the ovaries were removed within two years after a breast cancer diagnosis, the risk of death from cancer was reduced by 735, compared to women who never had the operation.

“What this research shows is that we need to remove the ovaries and we need to do it soon after breast cancer diagnosis,” Metcalfe said.

Women with BRCA2 mutations did not seem to benefit as much. Metcalfe said those cancers may respond differently than cancers in women with the BRCA1 mutation, or they may need more participants to detect a difference.

The researchers can’t say why removing the ovaries of women with the BRCA1 mutation after breast cancer diagnoses is tied to a reduced risk of death, but it appears to be related to hormones, Metcalfe said.

Surprisingly, though, women diagnosed when they were over age 50 – the average age of menopause in BRCA mutation carriers – did benefit from ovary removal. So did women whose breast cancers were not driven by estrogen.

“More research needs to be done to see what’s happening,” Metcalfe said.

Women with either gene mutation should still consider having their ovaries and tubes removed as a risk-reducing surgery, she said. The procedure will protect against ovarian cancer.

The American College of Obstetricians and Gynecologists says women should consider the surgery before age 40 or after they have completed their families.

Dr. Elizabeth Jewell, who was not involved with the new study, said the new finding suggests the surgery may affect the risk and outcome of breast cancer.

“This is an important conversation to have early in the course of treatment,” said Jewell, who is a gynecologic oncologist at Memorial Sloan Kettering Cancer Center in New York City.

“It adds additional justification for this surgical recommendation,” she said, noting that the timing of surgery may be pushed up for women with this genetic mutation and breast cancer. “I think that needs to be balanced with a woman’s quality of life from surgical menopause and their childbearing desires.”

Women with a family history of breast or ovarian cancer should be assessed to see if it may be related to a gene mutation, according the U.S. Preventive Services Task Force. If so, those women should receive genetic counseling and possibly BRCA testing. It’s estimated that one in 300 to 500 women has a BRCA mutation.

Metcalfe said women who are diagnosed with breast cancer before age 40, women of Jewish decent and women diagnosed with so-call triple-negative breast cancer may also consider getting tested.