MIAMI BEACH, Fla--Few women who undergo voluntary bilateral mastec-tomy as a prophylactic measure have regrets about having the surgery performed, according to a survey of 322 women who had the procedure. Patrick Borgen, MD, chief of the Breast Service at Memorial Sloan-Kettering Cancer Center, presented the data at the 14th Annual International Breast Cancer Conference.
Growing numbers of patients who test positive for a germline mutation in BRCA1 or BRCA2 are seeking prophylactic removal of the breasts, Dr. Borgen said, yet virtually nothing is known about the acceptance, efficacy, or long-term effects of this procedure.
This situation led the researchers to construct a national volunteer Prophylactic Mastectomy Registry. The women are self-selected by virtue of responding to advertisements in major United States magazines, primarily Modern Maturity, the monthly magazine produced by the American Association of Retired Persons. The respondents fill out a questionnaire about themselves, their operations, and their feelings about the procedures.
So far, more than 700 women have responded to the advertisements, and the registry continues to grow. "We are about to begin an outreach program to members of the American College of Surgeons to supplement this data set," he said.
Dr. Borgen pointed out that none of the women in the study had a diagnosis of cancer, and available evidence may suggest but does not prove that the procedure prevents cancer. He called bilateral mastectomy for the prevention of cancer "an untested, unproven, putative preventive measure," citing the lack of prospective studies.
Only Two Cases
The current survey, albeit unscientific, suggests that the procedure may be effective. Normally, Dr. Borgen said, in a cohort such as that involved in the survey, he would expect to find 30 cases of breast cancer; instead, the women reported just two cases--one woman developed breast cancer five years after the double mastectomy; the other, 20 years after surgery. Both women are now cancer free.
The women's reasons for having the operation included a strong family history of breast cancer, previous biopsies for suspicious lumps, and heavily fibrous breast tissue, which sometimes masks cancer from screening methods.
The vast majority of the women (83%) had undergone biopsies prior to their surgery, and most had had more than one biopsy. (One woman had undergone 25 procedures.)
Dr. Borgen said that in 68% of the cases, the woman's physician was the first to broach the subject of bilateral prophylactic mastectomy. About 29% of the women told the researchers they had initiated discussion about the operation.
About 94% of the women in the survey said that they had no regrets about undergoing the procedure. But among the 19 women who did express regret, all said that their doctors had initiated the discussions of prophylactic surgery. Dr. Borgen said that of these women, one third did not have a first-degree relative with breast cancer.
He was surprised to find that only about 12% of the women who had bilateral prophylactic mastectomy had received any psychological counseling. Just one of the 18 women who were unhappy about having undergone the procedure had received counseling before surgery.
Only 3% of the women had been tested for cancer-associated BRCA1 and BRCA2 gene mutations, mainly because the procedures were done between 1945 and 1995--in most cases, years before those genes were known.
Dr. Borgen says that while the survey lacks some degree of scientific validity, "there is still much to be learned from it," including information on the role of genetics in cancer development.