Women with breast cancer who undergo radiation treatment after mastectomy run a moderately increased risk of developing cancer of the esophagus, according to population-based study of roughly 244,000 women.

The chances of esophageal cancer occurring are about 3-times higher than normal 5 to 9 years after the radiation therapy, and about 2-times higher thereafter, investigators report in the American Journal of Epidemiology.

However, the actual rate of esophageal cancer was still low, at the equivalent of approximately 10 cases per 100,000 persons per year.

Commenting on his team’s findings, Dr. Alfred I. Neugut from Columbia University in New York said: “The interesting point is that, while there is an increased risk of esophageal cancer following breast cancer radiotherapy, it is not very large and should not affect the use of this type of therapy.”

He added, however, that doctors “may want to discourage these women from smoking.”

The team did find that there was no increase in risk of esophageal cancer with radiation treatment given after lumpectomy, which entails lower radiation exposure.

SOURCE: American Journal of Epidemiology, February 15, 2005.