Breast Cancer Associated With Melanoma Risk, And Vice Versa

NEW YORK SEP 22, 2004 -(Reuters Health) - There appears to be a bidirectional association between female breast cancer and cutaneous melanoma, according to results of a new study. While the finding might be confounded by increased surveillance in the two diseases, it does support increasing evidence of an overlapping genetic pathway.

"Epidemiologic studies have provided suggestive evidence of a link between cutaneous melanoma and breast cancer," Dr. Hensin Tsao, of Massachusetts General Hospital, Boston, and colleagues write in the September 20th issue of the International Journal of Cancer.

"Moreover," they point out, "carriers of mutations in the breast cancer predisposition gene, BRCA2, have an increased risk of melanoma while carriers of mutations in the melanoma susceptibility gene, CDKN2A, exhibit a higher than expected risk of breast cancer."

The researchers examined whether female breast cancer survivors in the Surveillance, Epidemiology, and End Results (SEER) database have an increased risk for melanoma, and vice versa. The team compared the expected number of cases to the observed number of cases.

Survivors of melanoma had an 11% increased risk of developing breast cancer. The risk was higher in patients diagnosed with melanoma at or before age 50 years (19% increased risk), those diagnosed more recently (17% increased risk), and for the first 3 years after the melanoma diagnosis (25% increased risk).

Overall, the risk of developing melanoma was increased by 16% in female breast cancer survivors. Younger patients (up to 50 years old) had a 46% increased risk of melanoma, while those who had undergone radiation therapy had a 42% increased risk.

"The elevated risk for cutaneous melanoma, especially among younger breast cancer patients, suggests that the genetic observations from high-risk groups may also be operative at a much lower level in the general breast cancer population," Dr. Tsao and colleagues conclude.

SOURCE:

• Int J Cancer 2004;111:792-794