Prognostic value of the percentage of positive fragments in biopsies from patients with localized prostate cancer

Abstract

Objective: To assess the prognostic value of the percentage of positive fragments (PPF) in biopsies from patients with localized prostate cancer (PCa) undergoing radical prostatectomy. Materials and methods: During the period from March 1991 to November 2000, 440 patients were selected. Cases receiving neoadjuvant or adjuvant hormone therapy, or adjuvant radiotherapy, were excluded, as were cases presenting Gleason scores higher than 6 at biopsy. PPF was defined as the total number of fragments divided by the total number of biopsy fragments times 100. This variable was initially divided into categories from 0 to 25%, 25.1% to 50%, 50.1 to 75% and 75% to 100%. During the postoperative period, patients were assessed every 2 months for 1 year, then every 6 months for 5 years, and then yearly. Biochemical recurrence was defined as serum PSA higher than or equal to 0.4 ng/mL. Median follow-up was 60 months. Results: One hundred and nine (24.8%) of the 440 patients under study had biochemical recurrence. In the univariate analysis, PPF significantly influenced disease-free survival (log-rank, p < 0.001), and patients with PPF between 75 and 100% presented a risk of a biochemical recurrence of the disease 3 times higher than patients with PPF between 0 and 25% (p < 0.001). After the Cox regression analysis, both serum PSA (p = 0.001) and PPF (p < 0.001) showed to be independent predictive factors for disease-free survival following surgery. Conclusion: PPF measurement in biopsy is a simple and practical method, which should be routinely used as a predictive factor for biochemical recurrence in patients with PCa presenting Gleason scores between 2 and 6.