Most Women With Family History of Breast Cancer Do Not Get Cancer

LONDON (Reuters Health) Oct 25 -A new report from the UK confirms that women who have a sister , mother or daughter with breast cancer have an above-average risk of developing the disease themselves, but the risk is not as great as often thought.

In fact, most women with a family of history of breast cancer will never get the disease themselves, according to the report, which appears in the October 27th issue of The Lancet. And most women who get breast cancer do not have a close relative with breast cancer .

"Women with a family history of breast cancer are W1likely to develop breast cancer themselves and even less likely to die from it," the report's lead author, Dr. Valerie Beral of the Imperial Cancer Research Fund's Cancer Epidemiology Unit in Oxford, told Reuters Health.

"Four out of five women who have a mother and a sister with breast cancer will never develop breast CaI1Cer, and 12 out of 13 will not die from breast cancer," she said. Dr. Beral's conclusions are based on an analysis of52 studies that included 58,209 women with breast cancer and 101,986 cancer-free women.

The analysis indicates that for women with a family history of breast cancer, their risk depends on the number of close relatives with the disease. For women with one close relative with breast cancer, the lifetime risk of being diagnosed with the disease was 8.0%. The risk was 13.3% for women with two first-degree relatives with breast cancer and 21.1% for those with three affected relatives.

Contrary to popular belief, the report shows that women with a family history of breast cancer are not likely to develop breast cancer at a young age. Most women with affected relatives who get breast cancer themselves develop the disease at age 50 or later, according to Dr. Beral.

"The findings are reassuring for younger women with a family history, as the risks of developing breast cancer are lower than is popularly believed," Dr. Beral said.

However, she added, "Older women with a family history of the 'disease should not be too complacent, as they continue to be at somewhat higher risk of breast cancer in middle age, and even at old ages."

But she pointed out that eight of nine women who are diagnosed with breast cancer -regardless of age - do not have an affected mother, sister or daughter .

Lancet 2001;358:1389-1399