Extended follow-up for prostate cancer incidence and mortality among participants in the Prostate, Lung, Colorectal and Ovarian randomized cancer screening trial.

Abstract

To examine prostate cancer (PCa) incidence and mortality by arm in the randomized Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial. Patients aged 55-74 years at 10 screening centres were randomized between 1993 and 2001 to an intervention or usual care arm. Patients in the intervention arm received six annual prostate-specific antigen (PSA) tests and four annual digital rectal examinations. The patients were followed for PCa incidence and for mortality via active follow-up processes and by linkage to state cancer registries and the National Death Index. For cancers identified through active follow-up, trial abstractors recorded the mode of diagnosis (screen-detected, symptomatic, other). A total of 38 340 patients were randomized to the intervention arm and 38 343 to a usual care arm. The median follow-up for mortality was 16.9 (intervention) and 16.7 years (usual care). There were 333 (intervention) and 352 (usual care) PCa cancer deaths, giving rates (per 10 000 person-years) of 5.5 and 5.9, respectively, and a rate ratio (RR) of 0.93 (95% confidence interval [CI] 0.81-1.08; P = 0.38). The RR for overall PCa incidence was 1.05 (95% CI 1.01-1.09). The RRs by Gleason category were 1.17 (95% CI 1.11-1.23) for Gleason 2-6, 1.00 (95% CI 0.93-1.07) for Gleason 7 and 0.89 (95% CI 0.80-0.99) for Gleason 8-10 disease. By mode of detection, during the trial's screening phase, 13% of intervention arm vs 27% of usual care arm cases were symptomatic; post-screening, these percentages were 18% in each arm. After almost 17 years of median follow-up, there was no significant reduction in PCa mortality in the intervention compared with the usual care arm. There was a significant increase in Gleason 2-6 disease and a significant reduction in Gleason 8-10 disease in the intervention compared with the usual care arm.