USC study indicates jump in reported prostate cancers linked to availability of routine testing, not to changes in causes of cancer
LOS ANGELES, May 2, 2001When cases of prostate cancer rose in the last two decades, more accessible testing and early detection most likely prompted the increase in incidence, conclude researchers at the Keck School of Medicine of the University of Southern California.
Soon after prostate-specific antigen (PSA) tests became available to detect prostate cancer in 1987, prostate cancer incidence increased steeply nationwide. Cases rose especially dramatically among men of high socioeconomic statusmeasured by income and education levelscompared to men of lower socioeconomic status, the researchers report in the May issue of the Journal of the National Cancer Institute. Before PSA testing became prevalent, doctors diagnosed fewer cases of prostate cancer, and cases were spread out almost equally among men of all socioeconomic groups (despite variations among ethnic groups). With their education and affluence, men of high socioeconomic status are more likely to benefit from improvements in disease detection, treatments and knowledge of risk factors. Easier access to health care increases the chances that these menregardless of race or ethnicitywill be tested for prostate cancer, which naturally may result in a cancer diagnosis, says Lihua Liu, USC preventive medicine researcher and lead author of the study.
Using data from the Los Angeles Cancer Surveillance Program, preventive medicine researchers examined about 83,000 invasive prostate cancer cases reported in Los Angeles County from 1972 to 1997. They estimated each patients socioeconomic status based on income and education statistics for the Census tract in which the patient lived at time of diagnosis.
From 1972 to 1987, before PSA testing, researchers found no relationship between patients socioeconomic status and the prostate cancer incidence rate, re
Contact: Jon Weiner
University of Southern California