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Race and the Will Rogers phenomenon in prostate cancer
S Vijayakumar1, F Vaida, R Weichselbaum
1University of Chicago Center for Radiation Therapy, Department of Radiation and Cellular Oncology, Illinois, USA.
Purpose:
With the introduction of prostate-specific antigen testing, the "Will Rogers phenomenon"--stage migration associated with more sensitive diagnostic and staging procedures--seemed likely to occur.
Materials And Methods:
Yearly values of prostate-specific antigen from 1988 to 1995 were determined for whites (n = 34) and African-Americans (n = 321). Pretreatment levels were used as objective surrogates of tumor cell burden. Changes in clinical stage and pathological grade by calendar year also were determined.
Results:
There was a statistically significant yearly decline in levels of prostate-specific antigen for African-Americans (12.2% per year). There was no significant decline among whites. Similar trends were seen on multivariate analysis that adjusted for stage and grade. There was clinical stage migration for whites and African-Americans. There was also a shift in tumor grade for both whites and African-Americans.
Discussion:
Over the past decade, African-Americans have shown a decline in tumor cell burden at the time of diagnosis as reflected by a decline in mean levels of prostate-specific antigen. For whites and African-Americans, there has been a shift to early clinical stages. The Will Rogers phenomenon, as demonstrated in African-Americans by decline in prostate-specific antigen and in whites and African-Americans by clinical stage migration, indicates lead-time and length biases, resulting in a more favorable disease profile at diagnosis for both groups. The decline in prostate-specific antigen among African-Americans indicates that the initial higher tumor cell burden seen in the past was caused by socioeconomic factors rather than inherited differences, and is likely to be ameliorated with widespread prostate-specific-antigen screening.