
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: WEDNESDAY, July 21, 1993                   TAG: 9307210155
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-6   EDITION: METRO 
SOURCE: Los Angeles Times
DATELINE:                                 LENGTH: Medium

BREAST CANCER GENETIC FACTOR DOWNPLAYED

In a finding that may lend some reassurance to women with a family history of breast cancer, Harvard researchers report that genetics appears to play a smaller role in development of the disease than had been thought.

Although previous studies have suggested that women with a mother and sister who have the disease have six to 14 times the normal risk of developing breast tumors, a major new study reported today in the Journal of the American Medical Association says that their risk is about 2.5 times normal. The chances are about twice normal if just the mother or the sister has the disease, also lower than previous estimates.

Breast cancer is the most common form of cancer in women. It will strike an estimated 175,000 in the United States this year, killing 45,000.

The new study also shows that, except in a small number of families in which many women are stricken with the disease, genetics plays only a small role in the onset of breast cancer. The survey of 121,700 nurses who have been monitored since 1976 indicates that only about 2.5 percent of breast tumors are genetic in origin.

If women have an affected mother or sister, "they need not feel they will inevitably develop breast cancer," said Dr. Graham Colditz, an epidemiologist at the Harvard School of Public Health.

"The most important feature of the study is that only a small proportion of breast cancer can be attributed to family history," said epidemiologist Louise Brinton of the National Cancer Institute. "There is a lot of misconception among the public that the risk [of breast cancer] is determined solely by whether or not they have relatives with it. That is not true."

In another report based on the nurses study to be published this week, the same team found that dietary supplementation with vitamins C and E provided no protection against breast cancer, but that normal levels of vitamin A in the diet may act as a protective factor.

by CNB