BOSTON -- The largest study of its kind to date shows that even after receiving the same treatment, breast cancer is more likely to recur in black women than it is in whites.

The findings are being presented today at the American Society for Therapeutic Radiology and Oncology annual meeting. They are contrary to the findings of previous research.

Scientists followed nearly 2,400 breast cancer survivors for three decades and found that breast cancer returned in 17 percent of African-American women who had a lumpectomy to remove breast cancer, followed by radiation. The cancer returned in 13 percent of white women who received the same medical treatment.

The study also confirmed widely known evidence that black breast cancer patients are more likely to have highly aggressive tumors, and be diagnosed at a later stage of the disease.

White women get breast cancer more frequently than do blacks, but black women have a higher mortality rate.

"This study confirms the aggressive nature of breast cancer in African-American women and emphasizes how important it is for all African-American women to see their health care providers regularly and to go for screening mammograms to try to catch any abnormalities early," said Meena S. Moran, M.D., the lead author of the study and a radiation oncologist at the Yale University School of Medicine.

"This study also points out the need for further research in evaluating the underlying molecular, genetic and biological differences in breast cancers in African-American women so that we can develop better strategies for helping these women beat their cancer."