March 30, 2010 - Among a group of patients who should received radiation therapy according to medical guidelines, 95 percent of patients who had lumpectomy went on to receive radiation, while only 78 percent of those who had mastectomy received radiation.
According to a new study from researchers at the University of Michigan Comprehensive Cancer Center, while radiation therapy is common after breast conserving surgery, it is much less frequent after mastectomy, even among women for whom it would have clear life-saving benefit.
The study included 2,260 women treated for breast cancer. Researchers assessed whether these women had lumpectomy or mastectomy, and whether they would be strong candidates for radiation therapy. Women who have particularly large tumors or cancer in four or more of their nearby lymph nodes are recommended to have radiation after mastectomy.
The study found that among the women who had a lumpectomy and should have received radiation therapy, 95 percent of patients did receive radiation. However, for those who had a mastectomy, only 78 percent who should have received radiation, according to the guidelines, did n fact receive radiation. Among the women in the study for whom radiation was less clearly beneficial, 80 percent of the lumpectomy patients had radiation while only 46 percent of the mastectomy patients did.
Results of the study, which appear online March 29 in the Journal of Clinical Oncology, found One in five women with strong indications for radiation after mastectomy failed to receive it.
Author Reshma Jagsi, M.D., D.Phil, assistant professor of radiation oncology at the University of Michigan Medical School, observed "a substantial number of breast cancer patients are being undertreated."
The study also found doctor participation strongly influenced radiation receipt. Patients who reported their surgeon was involved in the decision to receive radiation were more likely to receive radiation than patients whose doctor was less involved.
Researchers concluded that patients with strong indications for radiation after mastectomy, their risk of the cancer coming back in the chest wall or surrounding areas can exceed 30 percent. This is reduced by two-thirds if the patient undergoes radiation treatments, and overall survival is improved.
Reference: Journal of Clinical Oncology, DOI: 10.1200/JCO.2009.26.8433, published online March 29, 2010
For more information: jco.ascopubs.org
January 22, 2026 
