ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Monday, April 14, 1997 TAG: 9704140154
SECTION: NATL/INTL PAGE: A-3 EDITION: METRO
DATELINE: SAN DIEGO
SOURCE: ASSOCIATED PRESS
A Mayo Clinic study of 950 women who had the surgery found that it reduced breast cancer risk by 91 percent.
The increasingly common practice of surgically removing both breasts while they are still healthy is an effective, if radical, way of preventing breast cancer in women at high risk of the disease, a study finds.
Until recently, bilateral prophylactic mastectomy, as doctors call it, was rare. But the development of screening tests for the inherited bad genes that can trigger breast cancer has increased demand for this approach.
When a woman discovers she has a high genetic susceptibility to cancer, there is little she can do besides frequent checkups or having her breasts removed. Some doctors are reluctant to offer the genetic screening test because of uncertainty about whether a pre-emptive mastectomy actually works as well as common sense would suggest it should.
To help settle the issue, doctors from the Mayo Clinic followed up on 950 women who have had bilateral prophylactic mastectomies, mostly because of a strong family history of breast cancer. They found that it reduced their breast cancer risk by 91 percent.
It was not, however, totally effective. Even when the breasts are cut off, surgeons often leave behind tiny bits of breast tissue on the chest wall. These remnants still can turn cancerous. Furthermore, undetected cancer sometimes may already have spread to other parts of the body before the breasts are removed.
The study, directed by Dr. Lynn C. Hartmann, followed women who had the surgery between 1960 and 1993 - before screening for breast cancer genes became common.
Nevertheless, Hartmann said her findings are the first to suggest that mastectomies in women with cancer genes will work as intended.
``It's an extreme approach,'' she said. ``For a woman who decides to proceed, at least she now has some clear information instead of a question mark.''
Hartmann presented her results Sunday at a conference sponsored by the American Association for Cancer Research.
While there are no clear figures on how many women are opting for mastectomies to prevent cancer, Dr. Henry T. Lynch of Creighton University said the numbers have clearly increased since the discovery of two powerful cancer genes in 1994 and 1995.
Mutant forms of these genes, called BRCA1 and BRCA2, together cause about 5 percent to 10 percent of all breast cancer and 5 percent of all ovarian cancer. While rare, they greatly increase the cancer risk for those who get them.
A woman with either BRCA1 or BRCA2 has about an 85 percent lifetime risk of breast cancer. BRCA1 also gives her a 40 percent to 60 percent risk of ovarian cancer, while BRCA2 causes a 10 percent to 20 percent risk of ovarian cancer.
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