IS THERE A DIFFERENCE IN COMPLETION RATE OF RADIATION TREATMENT IN AFRICAN AMERICAN AND CAUCASIAN WOMEN IN CLINICAL TRIALS?

Breast cancer is a disease that can affect all women. However, the rate at which this disease affects women varies by race and ethnicity. When one analyzes incidence rates for a life threatening disease, a higher incidence rate for a certain group usually portends a higher death rate. However this is not necessarily true for breast cancer. In particular, when comparing incidence rates with their white counterparts, African American women have a lower incidence rate but a higher death rate. The phenomenon of racial differences or health disparities among cancer patients has been established several times by studies primarily associated with differences in health care in the general population. However, within randomized clinical trials, one does not anticipate that disparities in health outcome would be evident as all patients receive treatment in accordance with standard treatment protocols. The purpose of this study is to test this premise by asking the question: Is there a difference in radiation treatment when comparing African American and Caucasian women who are treated in randomized clinical trials? The study population includes patients from the National Surgical Adjuvant Breast and Bowel Project (NSABP) on various protocols (B15, B16, B18, B22, B23, B25, and B28). The focus was on patients who received chemotherapy in the form of Adriamycin and cyclophosphamide (AC), alone or prior to other chemotherapy agents. AC was given as adjuvant in all of the protocols. There were 9,646 Caucasian patients and 1,040 African-American (AA) patients. Among these patients were 3,504 Caucasian patients and 377 AA patients who received radiation therapy according to protocol.After adjusting for various potential confounders no evidence was found of a difference by race in total radiation therapy.Public health importance: Randomized clinical trials provide important evidence for the choices of breast cancer treatment. The success of such trials in providing an environment where patients received a standardized treatment would be called into question if there were treatment differences by race in those trials. This study did not find evidence of racial disparity in radiation therapy in the NSABP breast cancer trials examined