Tumour features in the control and screening arm of a randomized trial of prostate cancer.

OBJECTIVE

To compare tumour characteristics at the time of diagnosis of cancers detected in the screening and control arm at the Rotterdam section of the European Randomized study of Screening for Prostate Cancer.

METHODS

Data were retrieved from the Rotterdam section of the ERSPC. Men were randomized to the screening arm (n=21,210) or the control arm (n=21,166). Men randomized to screening were offered PSA testing every 4 years. Through linkage with the cancer registry, men randomized to the control arm were detected. The biopsy Gleason score was determined in 1,591 and 373 patients in the screening and control arm, respectively. TURP, radical prostatectomy (RP) and cystoprostatectomy were evaluated for Gleason score, pathological (p)T stage and tumour volume.

RESULTS

More prostate cancers were detected in the screening arm (15.9 vs. 4.2 per 1000 man years, p<0.0001). Clinical stage distribution as well as biopsy and RP Gleason score distribution were significantly less favourable in the control arm. The incidence in man years of advanced disease (i.e. T4/N1/M1) was higher in the screening arm (6.0 per 100,000) as compared to the control arm (4.6 per 100,000). The 5-year PSA progression free survival after RP was 68% in the control arm and 89% in the screening arm (p<0.0001). The proportion of Incidental prostate cancers was 9.3% of all cancers detected in the control arm.

CONCLUSIONS

Although the number of men with advanced prostate cancer is slightly higher in the screening arm, the proportion of prostate cancers with favourable features is increased in the screening arm as compared to that in the control arm.