Chemotherapy Not Needed for Most Breast Cancers

NEW YORK (Reuters Health) - Chemotherapy with drugs called aromatase inhibitors is unnecessary after lumpectomy, radiation and 5 years of tamoxifen for the vast majority of women with breast cancer, researchers reported at the annual meeting of the American Society for Therapeutic Radiation and Oncology in Denver.

Principal researcher Dr. Gary Freedman, of Fox Chase Cancer Center in Philadelphia, presented results of a study of 471 women diagnosed with breast cancer. All women underwent lumpectomy and received radiation and 5 years of tamoxifen. One hundred fifty two women also received chemotherapy with aromatase inhibitors.

Freedman and colleagues analyzed the study group to determine which women benefitted from the addition of chemotherapy. They found that women who were disease-free 5 years after surgery, radiation and tamoxifen had just a 2.5 percent risk of their cancer returning at 10-year follow-up.

"In clinical practice, a benefit level of greater than 3 percent is commonly used to select patients for...chemotherapy," Freedman told Reuters Health. "Assuming a 40 percent reduction (in the risk of cancer returning) by the addition of an aromatase inhibitor to 5 years of tamoxifen therapy, the absolute benefit would occur in 1 percent of patients."

Still, some women may benefit from chemotherapy, Freedman noted, such as those who are premenopausal, have cancer in several lymph nodes, or have major diseases in addition to their cancer, he added.

"For women who are over 60, the overwhelming number of deaths are due to non-breast cancer causes, further minimizing the benefits of chemotherapy," Freedman noted.