RESUMO
This study aimed to evaluate tumor progression as assessed by PSA level of curative treatment for localised prostate cancer by either radiotherapy or prostatectomy. From 1987 to 1993, 180 patients were treated for clinically localised prostate cancer either by radiotherapy or prostatectomy. One hundred and five patients with clinical T1T2N0M0 were eligible for this study. Forty five underwent external beam radiotherapy and 60 had a radical prostatectomy. After radiotherapy PSA slowly decreased to reach a nadir 18 months after treatment. Any subsequent increase from this lowest post treatment level is associated with tumor progression. After radical prostatectomy PSA becomes undetectable and any increase will be regarded as evidence of tumor progression. The median PSA level before treatment and the median length of follow-up were comparable for the two groups. There was no statistically significant difference in overall survival and biological evidence of disease progression at 5 y. Analysis of the evolution of median PSA level shows a progressive decline during the 4 y after radiotherapy. After radical prostatectomy PSA become undetectable, 4 y after treatment PSA levels become comparable in the two groups. The biochemical free survival was 60% for the prostatectomy group and 62% for the radiotherapy group. PSA is an effective marker of tumour progression after surgery or radiotherapy for localised prostate cancer. In our retrospective study recurrence rates at 5 y were not significant but direct comparisons are limited due to the Gleason score of the two groups. PSA levels can take up to 4 y to reach a nadir after radiotherapy.
