Purpose
During active surveillance (AS) for localized prostate cancer (PCa), first surveillance biopsy timing varies. We analyzed the Canary Prostate Cancer Active Surveillance Study (PASS), to determine biopsy timing influence on rates of PCa adverse reclassification at first AS biopsy.
Materials/Methods
Of 1,085 participants in PASS, 421 had <34% cores involved with cancer, Gleason sum ≤6, and thereafter underwent on-study AS biopsy. Reclassification was defined as increase in Gleason sum and/or ≥34% of cores with PCa. First AS biopsy reclassification rates were categorized as <8, 8–13 and >13 months post-diagnosis. Multivariable logistic regression determined association between reclassification and first biopsy timing.
Results
Of 421 men, 89 (21.1%) experienced reclassification at first AS biopsy. Median time from PCa diagnosis to first AS biopsy was 11 months (IQR 7.8–13.8). Reclassification rates at <8, 8–13 and >13 months were 24%, 19%, and 22%, (p=0.65). On multivariable analysis, compared to men biopsied at <8 months the odds ratios (OR) of reclassification at 8–13 and >13 months were 0.88 (95%CI 0.5,1.6) and 0.95 (95% CI 0.5,1.9), respectively. PSA density ≥0.15 (reference <0.15, OR 1.9 [95%CI 1.1, 4.1]) and body mass index (BMI) ≥35 (reference <25 kg/m2, OR 2.4 [95%CI 1.1,5.7]) were associated with increased odds of reclassification.
Conclusions
Timing of first AS biopsy was not associated with increased adverse reclassification but PSA density and BMI were. In low-risk patients on AS, it may be reasonable to perform first AS biopsy at a later time, reducing overall cost and morbidity of AS.