To the Editor.
—I read with great interest the article by Dr Eley and colleagues1 regarding racial differences in survival from breast cancer. This investigation is one of the most complete, well-designed, and well-conducted studies to determine the nature of racial differences in breast cancer survival. The data-collection methods, management of confounding factors, and statistical analyses were exceptional.I have a question for the authors regarding frequency matching of white subjects to black subjects by age. By matching (overmatching) on this important variable, possible comparisons of age as a factor in survival were eliminated. Several studies2-4 have indicated significantly younger age at diagnosis in African-American women compared with white women, along with poorer survival rates, which may indicate basic biological differences between tumors in these two groups. Age may be a major explanatory variable in survival differences between races, in addition to or instead of those found in
Joslyn SA. Racial Differences in Survival From Breast Cancer. JAMA. 1995;273(13):1000. doi:10.1001/jama.1995.03520370040031