BACKGROUND.
Much of the recent increase in prostate carcinoma incidence has been attributed to screening with prostate specific antigen (PSA). Controversy exists as to whether this screening will ultimately impact prostate carcinoma mortality. Until adequate time elapses since PSA screening became widespread, or a randomized trial of PSA screening is completed, the effect of PSA screening on prostate carcinoma mortality cannot be determined. In the interim, stage specific prostate carcinoma incidence rates may provide an indication of the effect of PSA screening.
METHODS.
Annual stage specific age-adjusted prostate carcinoma incidence rates for the years 1973 through 1994 were obtained from the Metropolitan Detroit Cancer Surveillance System (MDCSS), a member of the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program. These incidence rates were analyzed for trends using Poisson regression analysis.
RESULTS.
There were 10,801 cases of prostate carcinoma in black men and 31,501 in white men during the 22-year period. Incidence rates for stages of local and regional prostate carcinoma reached a maximum in 1992 and 1993. Distant stage prostate carcinoma incidence has steadily declined since 1989 ( P < 0.001), the year in which the increasing trend in the incidence rates for local and regional stage prostate carcinoma were first noted.
CONCLUSIONS.
These findings suggest that a substantial proportion of early stage prostate carcinoma detected by PSA is in fact clinically important and that early detection of these carcinomas has resulted in a continuous decline in the stage of metastatic prostate carcinoma since 1989.