Prostate cancer incidence trends in Spain before and during the prostate-specific antigen era: impact on mortality

Although prostate cancer has recently registered increasing incidence and decreasing mortality in Spain, no analysis has yet been made of these two indicators to ascertain the magnitude of and reasons for these trends.

The time trend in invasive prostate cancer incidence from 1975 to 2004 was studied by combining data from 13 Spanish population-based cancer registries. Change-point Poisson regression models were fitted for all men and for two age groups (45-64 and 65+ years). Age-period-cohort models were used to study cohort and period effects. In addition, we studied the time trend in prostate cancer mortality in Spain for the period 1980-2007.

Incidence increased annually by 1.3% from 1975 to 1990 and by 7.3% thereafter. Until 1990, the percentage increase was low and indeed similar for both age groups. While the subsequent increase in the two age groups was greater, this was particularly marked among the youngest men, with a decrease being observed in age groups >85 years in the last quinquennium. Mortality increased by an annual figure of 0.7% until 1998, after which it decreased by 3.6% per annum until 2007.

Despite the dramatic rise in incidence from 1990 onwards, mainly due to opportunistic screening, prostate cancer mortality was only observed to decline slowly from 1998. If prostate-specific antigen screening remains at a similar level in Spain, overdiagnosis may well become an important chronic side-effect and health problem.