More favorable tumor features and progression-free survival rates in a longitudinal prostate cancer screening study: PSA era and threshold-specific effects

Objectives. To describe the changes in pathologic outcomes and progression-free survival (PFS) rates after radical retropubic prostatectomy for clinically localized prostate cancer in men whose cancers were detected in a 12-year longitudinal prostate cancer screening study. Methods. Between 1989 and 2001, more than 36,000 men participated in a digital rectal examination-based and prostate-specific antigen (PSA)-based screening program. In 1995, the PSA cutoff for biopsy recommendation was lowered from 4.0 ng/mL to 2.6 ng/mL, and the biopsy protocol was changed from four to at least six-sector biopsies. From the screening study, 2952 men were diagnosed with cancer and 2241 of these men underwent radical retropubic prostatectomy. We analyzed the differences in clinical and pathologic stage and PFS after surgery, according to the greater PSA cutoff era (1989 to 1995) and lower PSA cutoff era (1996 to 2001). Results. A significant downward clinical and pathological stage migration was found toward T1c and organ-confined disease, respectively, in men whose cancer was detected in the lower PSA cutoff era. Furthermore, men with cancer diagnosed in the lower PSA cutoff era had improved PFS rates 5 and 8 years after radical retropubic prostatectomy (P = 0.007). These changes occurred without a significant increase in the proportion of unimportant tumors (organ confined, smaller than 0.5 cm³ without a Gleason pattern of 4 or 5). Conclusions. These findings support the enhanced detection of favorable cancer and improved PFS rates with lower PSA cutoffs and more intensive biopsy regimens, although the follow-up and lead-time and length-time biases, as well as improvements in surgical technique, might also have affected these results.