Prostate cancer adverse pathology reclassification in patients undergoing active surveillance in a long-term follow-up series

Background: Active surveillance (AS) has become a valid option for patients with a very low risk of prostate cancer (PC) with a widespread application. There are still a few series, with a medium follow-up longer than 5 years, reporting data on pathological upgrading. The objective is to evaluate the changes in surveillance biopsies of patients with low-risk PC in a long-term follow-up and determine if a longer stay in AS could involve worse pathological findings.

Materials and methods: A retrospective analysis of our institutional database of patients with PC undergoing AS during 2004 to 2018 was performed. The inclusion criteria were prostate-specific antigen (PSA) ≤ 10 ng/mL, Gleason grade 1 and T1c/T2a. Patients were assessed by serum PSA level and digital rectal examination at 6-month intervals. Transrectal ultrasound-guided prostate biopsies were performed during the first year of follow-up, and every 2 or 3 years thereafter. The pathology details of biopsies were analyzed and compared with the current series on AS.

Results: Three-hundred nineteen patients undergoing AS were evaluated with a median follow-up of 5.3 years and a mean age of 67.4 years. Sixty-three patients did not meet all the criteria to be considered low-risk PC but were included in the analysis. Overall, 128 patients (40.1%) underwent active treatment (84.7% of them due to pathological progression in surveillance biopsies). The proportion of patients with a reported upgrading ranged between 19.4% and 35.3%, although only the fourth biopsy showed an upgrading proportion of over 30%. Limitations include the retrospective design of the study and the existence of different protocols between other cohorts that make it difficult to compare their results.

Conclusions: For patients who remained in surveillance the percentage of upgrading increased slightly with the time, being more frequent after the third-surveillance biopsy. These findings support the importance of extending surveillance biopsies for patients who remain candidates for curative treatment.