Introduction

Active surveillance (AS) represents a safe management strategy to reduce the risk of overtreatment in men with low risk prostate cancer (PCa). However, patients on AS must undergo PSA testing and repeated biopsies over time in all proposed protocols and patients are subjected to discomfort and anxiety as well as to the complications of repeated biopsies. We tried to identify the predictors of progression-free survival (PFS) at a single institution AS program in order to identify patients in whom repeated biopsies could be avoided or reduced in frequency.

Methods

Between 2009 and 2016, 235 consecutive patients affected by low-risk PCa according to PRIAS criteria (cT1/T2a; PSA<10 ng/ml; PSA density <0.2; Gleason score <7; <3 positive cores) were enrolled in our AS program. Tumor progression was defined as pathological upgrading (Gleason >6 or >2 positive cores) at repeated yearly biopsies. First, Kaplan-Meier analyses were used to quantify progression-free survival at 1, 3 and 5 years, respectively. Second, we identified patients who were progression-free at 3 years of follow-up. Finally, univariable and multivariable logistic regression analyses were used to predict 3-year PFS. Covariates consisted of age, total PSA, clinical stage (cT) and number of positive cores at the time of enrolment as well as negative (no cancer) 1-year biopsy.

Results

Progression-free survival rate was 85%, 55%, and 40% at 1, 3 and 5 years, respectively. Median follow-up was 19 months. Overall, 56 (23.8%) patients were progression-free at 3 years of follow-up. Median number of cores at enrolment in AS program was 16 (IQR: 14-20), while median number of cores at first-year biopsy was 18 (IQR: 14-20). At univariable analyses, total PSA and negative 1-year biopsy were significant predictors of 3-year PFS (all p<0.05). Patients with negative biopsy at 1 year had a 3-year PFS of 75.8 vs. 29.0% in those with positive biopsy at 1-year. These results were confirmed at multivariable analyses, where a negative 1-year biopsy represented the only independent predictor of 3-year PFS (OR: 2.47; p=0.04).

Conclusions

The first biopsy after enrolment in AS program is an important predictor of PCa progression in the first 3 years in men on AS. Negative findings at 1-year biopsy suggest a high chance of 3-year PFS. Patients with negative 1-year biopsy could be followed-up with less stringent biopsy protocol, in order to reduce possible biopsy-related side effects and discomfort.

Funding

none