Radiation after mastectomy underused

While radiation therapy is common after breast conserving surgery, it's much less frequent after mastectomy, even among women for whom it would have clear life-saving benefit. This is according to a new study from researchers at the University of Michigan Comprehensive Cancer Center.

The study looked at 2,260 women treated for breast cancer, assessing whether they 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 patients who should receive radiation therapy according to medical guidelines, 95 percent of those who had lumpectomy went on to receive radiation, but only 78 percent of those who had mastectomy received radiation. Among women for whom radiation is less clearly beneficial, 80 percent of the lumpectomy patients had radiation while only 46 percent of the mastectomy patients did.

“A substantial number of breast cancer patients are being undertreated. One in five women with strong indications for radiation after mastectomy failed to receive it. Radiation can be a life-saving treatment,” says study author Reshma Jagsi, M.D., D.Phil, assistant professor of radiation oncology at the U-M Medical School.

The fact that 95 percent of patients who had lumpectomy received radiation in the two metropolitan areas we studied indicates that we can do better than we are currently doing for the selected mastectomy patients who also need radiation. More attention needs to be paid to radiation after mastectomy,” Jagsi says.

Results of the study appear online March 29 in the Journal of Clinical Oncology.

The study also found that 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.

“Even patients who wanted to avoid radiation therapy were very likely to receive it if their surgeons were highly involved in the decision process. We need to do a better job of educating both patients and physicians regarding the benefits of radiation after mastectomy in certain circumstances, and we need to encourage physicians to help their patients as they make these important decisions,” Jagsi says.

In 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.

Methodology: The researchers surveyed 2,260 women in the Los Angeles and Detroit metropolitan areas who had been diagnosed with breast cancer between 2005 to 2007. Women were identified through the Surveillance Epidemiology and End Results registry. Participants were asked about their breast cancer diagnosis and treatment, including whether they received radiation therapy.

Breast cancer statistics: 194,280 Americans will be diagnosed with breast cancer this year and 40,610 will die from the disease, according to the American Cancer Society

Additional authors: Paul Abrahamse, M.A., Sarah T. Hawley, Ph.D., M.P.H., Jennifer J. Griggs, M.D., M.P.H., and Steven J. Katz, M.D., M.P.H., all U-M Comprehensive Cancer Center; Monica Morrow, M.D., Memorial Sloan-Kettering Cancer Center; John J. Graff, Ph.D., M.S., Karmanos Cancer Institute; Ann S. Hamilton, Ph.D., M.A., University of Southern California

Funding: National Cancer Institute, American Cancer Society, California Department of Public Health, Centers for Disease Control and Prevention

Reference: Journal of Clinical Oncology, DOI: 10.1200/JCO.2009.26.8433, published online March 29, 2010

Resources:
U-M Cancer AnswerLine, 800-865-1125
U-M Comprehensive Cancer Center, www.mcancer.org
U-M Cancer Surveillance and Outcomes Research Team www.med.umich.edu/cansort/