December 8, 2005

Breast cancer survivors face other cancer risks

NEW YORK (Reuters Health) - Women who survive a bout with
breast cancer are at increased risk of developing cancers of
the lung, stomach, and colon, among several others, new
research suggests.

The elevated risk of other cancers could be due to the
treatment given to fight the breast cancer, or perhaps to a
genetic predisposition to develop cancer, the researchers

The findings, which appear in an online issue of the
International Journal of Cancer, are based on a study of
525,527 women from 13 population-based cancer registries who
were diagnosed with breast cancer and followed for other
malignancies from 1943 to 2000.

Compared with the general population, breast cancer
survivors were 25 percent more likely to develop a second
malignancy, lead author Dr. Lene Mellemkjaer, from the Danish
Cancer Society in Copenhagen, and colleagues report.

Survivors were at increased risk for stomach cancer,
colorectal cancer, lung cancer, soft tissue sarcoma, melanoma,
non-melanoma skin cancer, endometrial cancer, ovarian cancer,
renal cancer, thyroid cancer, and leukemia. The elevated risks
ranged from 22 percent for colorectal cancer to 125 percent for
soft tissue sarcoma.

As the time from breast cancer diagnosis increased, so did
the risk of a second malignancy. In keeping with this finding,
the older a woman was when breast cancer was diagnosed, the
less likely was she to develop a second malignancy.

"The excess of cancer after a breast cancer diagnosis is
likely to be explained by treatment for breast cancer and by
shared genetic or environmental risk factors, although the
general excess of cancer suggests that there may be additional
explanations such as increased surveillance and general cancer
susceptibility," the authors conclude.

SOURCE: International Journal of Cancer, online December 8,