Slide of endometrial cancer. (Duke University Medical Center/Rex Bentley) Slide of endometrial cancer. (Rex Bentley/Duke Health)

 

Women with a mutation in the BRCA1 gene, which is already linked to breast and ovarian cancers, also face a higher risk of a deadly type of uterine cancer, according to a new study.

Lead author Noah Kauff, director of Clinical Cancer Genetics at the Duke Cancer Institute, said the study was the first "conclusive link" between the gene defect and an increased likelihood of serous endometrial carcinoma, a type of cancer that affects the lining of the uterus and has a mortality rate of 50 percent.

Many women with BRCA mutations have their breasts, ovaries and fallopian tubes removed to reduce their risk of developing cancer. Angelina Jolie received worldwide attention in 2013 when she announced she had a BRCA1 defect and would undergo risk-reduction surgery.

Kauff, in an interview, said the data from the new study was so striking that women should talk to their doctors about the possibility of having their uteruses removed at the same time they are having their ovaries and tubes removed.

The study, which was published online Thursday in the journal JAMA Oncology, involved almost 1,100 women in the United States and Britain who were followed for five years. All of them carried BRCA1 or BRCA2 mutations and previously had undergone surgery for the removal of their ovaries and fallopian tubes.

The researchers found that eight women developed uterine cancer — a slightly higher rate than in the general population but not statistically different. But when they analyzed the type of uterine cancer, they found something surprising: Five of the eight cases were serous endometrial cancer, an uncommon cancer, and all but one of them had the BRCA1 mutation.

The rate of that cancer, Kauff said, was 22 times higher than expected by the researchers. That made the finding highly significant, he said, even though the actual number of cases was small.

Although serous endometrial cancer accounts for only 10 percent of all uterine cancers, he said, it is responsible for 40 percent of the deaths.

"It might make a great deal of sense at the time of preventive surgery to add hysterectomy," he said, adding that the study's implications were less clear for women who had already undergone surgeries. And he added that some women might want to retain their uteruses until a later time, if they wanted to get pregnant using assisted reproductive technology.

An accompanying editorial in the journal said that although the study "suffers from a small number of cases ... perhaps it is time to consider that the line for risk-reducing gynecological surgery in patients with BRCA mutations not stop at the ovaries and fallopian tubes."

Theodora Ross, director of the UT Southwestern Medical Center's Cancer Genetics Program, said the study advances understanding of the role of BRCA1 mutations, but that more research is needed to help women and clinicians make difficult decisions about managing their cancer risk.

"The data in this study do not suggest that if you have a BRCA1 or BRCA2 mutation you should have a hysterectomy to reduce your risk further," she said. "Instead, a discussion of the risks and benefits with your genetic counselor and gynecologist will help patients make a decision that is difficult because information remains incomplete and therefore inconclusive."

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