Collin SM et al. (2008) Prostate-cancer mortality in the USA and UK in 1975–2004: an ecological study. Lancet Oncol 9: 445–452

The uptake of PSA screening since its introduction around 1990 has been markedly different in the USA and UK (57% vs 6%, respectively, by 2001); therefore, an effect of screening on prostate cancer mortality might be revealed by a comparison of these countries' prostate cancer mortality rates. Collin et al. assessed trends in prostate cancer mortality and incidence in the USA and UK between 1975 and 2004, and attempted to interpret these trends in relation to differences in PSA screening and treatment.

The researchers analyzed statistics from Cancer Research UK and the US National Cancer Institute Surveillance, Epidemiology and End Results (SEER) program. Trends in age-specific and age-adjusted prostate cancer mortality were similar in the USA and UK until the mid-1990s, when mortality peaked at very similar rates in both countries. Between 1994 and 2004, however, the rate of decline in age-adjusted prostate cancer mortality in the US was almost four times that in the UK; the difference was particularly apparent for men aged ≥75 years.

The differential decline in mortality between the two countries during 1994–2004 could be partly attributable to an early effect of increased initial screening in the US, but could also reflect treatment differences or other factors such as bias due to misattribution of cause of death. The authors await the findings of randomized, controlled trials to verify the effect of PSA screening on prostate cancer mortality.