Abstract

Objective: To evaluate long-term outcomes of active surveillance (AS) applied in low-risk prostate cancer patients, and the impact of re-biopsy results on the prediction of progression.

Material and methods: In our clinic, patients who had undergone AS for low-risk localized prostate cancer between the years 2005-2013 were included in the study. Our AS criteria are Gleason score ≤6, prostate- specific antigen (PSA) level <10 ng/mL, number of positive cores <3, maximum cancer involvement ratio <50% each core. Immediate re-biopsy (within 3 months) was performed to 65 patients who accepted AS. Finally, 43 patients who met re-biopsy criteria were included in the study. Prostate biopsy specimens were harvested from 12 cores under the guidance of transrectal ultrasound (TRUS). Re-biopsy was performed within 3 months (1-12 weeks). In re-biopsy, a total of 20 core biopsies were performed including the far lateral (6 cores) and transition zone (2 cores) in addition to standard 12 core biopsy. Our follow-up protocol is PSA measurement and digital rectal examination (DRE) every 3 months within the first 2 years, than every 6 months. Control biopsies was performed one year later and once upon every 3 years to patients whose PSA levels and DREs were normal at follow-up visits. More than 2 tumor invaded cores or 50% tumor in one core, and Gleason score exceeding 6 points were accepted as indications for definitive treatment. Patients were divided into two groups by re-biopsy results and compared according to the time to progression. We have done multivariate regression analysis to predict prognosis by using data on age, PSA level, and detection of tumor in re-biopsy specimens.

Results: Patients’ median age was 61 years and PSA level was 5 (2.7-9) ng/mL. Tumor was detected in 22 (34%) patients at re-biopsy and they underwent definitive treatment. Additionally tumor was detected in 9 patients, but active surveillance was maintained because their pathologic results met active surveillance criteria. Median follow time was 42 (24-117) months. Definitive treatment was performed in 9 (21%) patients. PSA recurrence was not detected in none of 9 patients during 38 months of follow up. Only the presence of tumor in re-biopsy specimens was found predictor of disease progression in multivariate analysis.

Conclusion: We think that AS is safe method for low- risk localized prostate cancer patients, if it is performed in compliance with certain criteria and regular follow up, and early re-biopsy can be useful either during early period or long term follow-up.