Objective: To investigate the prognostic value of the Gleason score in prostate cancer.
Patients and methods: A consecutive series of 305 men with prostate cancer diagnosed at transurethral resection (1975-1990) and with no curative treatment was analysed. There was no assessment of prostate-specific antigen level during this period. The mean (range) age at diagnosis was 73.7 (52-95) years and the mean follow-up was 6.4 (0-22) years. The influence of Gleason score and the percentage of the specimen area with tumour (% cancer) on disease-specific survival were assessed using Kaplan-Meier analyses.
Results: Of 305 cancers, 22% had a Gleason score of 4-5, 29% of 6, 18% of 7 and 32% of 8-10. At the follow-up, 89% of the men had died, of whom 42% had died from prostate cancer. The disease-specific 10-year survival was 56%. The disease-specific mean survival (DSMS) for Gleason score 4-5, 6, 7 and 8-10 was 20, 16, 10 and 5 years, respectively (P < 0.001). The DSMS did not differ significantly between Gleason 4 and 5 or between 8-10. There was a trend towards shorter survival for Gleason 4 + 3=7 (DSMS 9 years) than GS 3 + 4=7 (DSMS 13 years; P = 0.16). Gleason score and % cancer were independent predictors of DSMS (P < 0.001).
Conclusion: The long-term prognosis of prostate cancer on deferred treatment is predicted well by the Gleason score. Four prognostic categories of prostate cancer are suggested, i.e. Gleason score 4-5, 6, 7 and 8-10.