Trends in incidence and mortality rates for prostate cancer before and after prostate-specific antigen introduction. A registry-based study in southeastern Netherlands, 1971-1995.

The incidence of prostate cancer has increased considerably over the past two decades, partly due to the increased detection of subclinical cases. In southeastern Netherlands, a region of almost 1 million inhabitants with good access to specialised medical care, prostate-specific antigen (PSA) assays were not introduced until 1990, allowing us to investigate the nature of the increases in incidence. Age-adjusted (European Standardised Rate) and age-specific rates were calculated using incidence data from the population-based Eindhoven Cancer Registry and mortality data from Statistics Netherlands. The age-adjusted incidence, which increased from 36 per 100,000 in 1971 to 55 per 100,000 in 1989, included all grades as well as metastasised prostate cancer. The age-adjusted mortality mainly fluctuated in this period, but increased among men aged 55-64 years from 12 per 100,000 in 1980 to 25 per 100,000 in 1989. After 1990, the age-adjusted incidence further increased to 80 per 100,000 in 1995, the increase representing mainly low-grade localised prostate cancer, presumably due to increasing opportunistic PSA testing, especially after 1993. A real increase in incidence may have occurred before 1993. However, pending results of randomised trials, judicious application of PSA testing seems justifiable to avoid unnecessary intervention without reducing mortality.