Researchers looked at 20,063 breast cancer patients treated at eight U.S. cancer centers between 1998 and 2007 and found that 50 of those patients had developed some form of leukemia within 10 years after radiation therapy, chemotherapy or a combination of the two.

 

The retrospective study estimated the risk at about 0.5 percent, which was double the 0.25 percent previously found.

 

Antonio Wolff, M.D., a professor of oncology at the Johns Hopkins University School of Medicine in Baltimore, which led the research, said this study could help early-stage breast cancer patients and their physicians think more carefully about the use of chemotherapy for “just-in-case” reasons, especially when patients have a low risk of cancer recurrence.

 

In recent years, research has found that postsurgical chemotherapy for breast cancer mostly benefits a small and select group of patients and it is no longer recommended for all patients with Stage 1 breast cancer.

 

 Each breast cancer case should be evaluated individually and factors such as tumor size, whether it has spread and its genetic makeup must be considered, Dr. Wolff noted.