POPULATION-BASED STUDY OF LONG-TERM SURVIVAL IN PATIENTS WITH CLINICALLY LOCALIZED PROSTATE-CANCER

Background Choice of treatment in localised prostate cancer has been h ampered by a lack of unbiased, representative data on outcome. Most ex isting data have come from small cohorts at specialised academic centr es; precise overall and cancer-grade-specifc data are not available, a nd the data are subject to differential staging bias. Randomised clini cal trials have been undertaken, but the results will not be available for another decade. We have carried out a large population-based stud y to ascertain overall and prostate-cancer-specific survival in men tr eated by prostatectomy, radiotherapy, or conservative management. Meth ods Data for 59 876 cancer-registry patients aged 50-79 were analysed. We examined the effect of differential staging of prostate cancer by analysing the data both by intention to treat and by treatment receive d. Estimated survival was calculated by the Kaplan-Meier method. Findi ngs By the intention-to-treat approach, 10-year prostate-cancer-specif ic survival for grade 1 cancer was 94% (95% CI 91-95) after prostatect omy, 90% (87-92) after radiotherapy, and 93% (91-94) after conservativ e management. The corresponding survival figures in grade 2 cancers we re 87% (85-89), 76% (72-79), and 77% (74-80); those in grade 3 cancer were 67% (62-71), 53% (47-58), and 45% (40-51). Although the intention -to-treat and treatment-received analyses yielded similar results for radiotherapy and conservative management, the 10-year disease-specific survival after prostatectomy differed substantially (83% [81-84] by i ntention to treat vs 89% [87-91] by treatment received). Interpretatio n The overall and cancer-grade-specific survival found in this study d iffer substantially from those in previous studies. Previous studies t hat used a treatment-received approach have generally overestimated th e benefits of radical prostatectomy. We found that grade 3 tumours are highly aggressive irrespective of stage.