Black and Hispanic women are less likely than white women to receive the radiation therapy routinely prescribed following surgery for early breast cancer, according to a study that Dana-Farber Cancer Institute researchers will present at the annual meeting of the American Society of Clinical Oncology in Chicago.

Although the disparity in rates is relatively small, the findings suggest that thousands of black and Hispanic breast cancer patients may be undertreated following a lumpectomy. The data (abstract 535) will be presented during a poster session on Monday, June 2, 8 a.m. – 12 p.m. CT, Lakeside Center Building, 450A.

Rachel Freedman, MD, an oncology fellow in Dana-Farber's Breast Oncology Center, noted that although some women in all racial and ethnic groups fail to receive the recommended course of radiation following breast-conserving surgery (lumpectomy) — which has largely replaced mastectomy for small, early breast tumors — black and Hispanic patients have the lowest rates among all racial/ethnic groups studied.

The regimen calls for short sessions of radiation five days a week for six to seven weeks, and "there are many barriers that may prevent this from happening," Freedman noted. Often there are logistical problems: distance to a radiation treatment facility, conflicts with work, transportation and child care issues, she said. Other factors include insurance status, possible lack of a recommendation for radiation in older patients or those perceived to have lower risk cancers, as well as patient preferences and priorities.

Freedman, along with senior author Nancy L. Keating, MD, MPH, of Brigham and Women's Hospital and two other co-authors, analyzed cancer registry data on 375,547 women with stage I or II breast cancer. They calculated rates of receiving lumpectomy and radiation or mastectomy (termed "definitive primary therapy") and the rates of having a lumpectomy without radiation (non-definitive therapy) among racial/ethnic groups.

Compared with white women, black women had lower odds of receiving definitive therapy (82.1 percent for blacks versus 86.1 percent for whites). Hispanic women also had a lower rate, 83.2 percent, while the rate among Asian women, 89.4 percent, was higher than it was for white women.

"The difference between blacks and whites may seem small percentage wise — 4 percent — but if 200,000 women are diagnosed with early breast cancer every year, 4 percent amounts to 8,000 women who are not receive definitive primary therapy," said Freedman.

"We don't know the exact reasons for these disparities," Freedman said. "We are interested in finding out what is happening in these women, and subsequent studies need to examine how other factors have contributed to these findings. In a follow-up study, we are examining pertinent issues such as insurance status, education level, and income."

The other co-authors are Eric Winer, MD, of Dana-Farber, and Yulei He, PhD, of Harvard Medical School's Department of Health Care Policy. Dana-Farber Cancer Institute (www.dana-farber.org) is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), designated a comprehensive cancer center by the National Cancer Institute.