Affiliation: | 1. Academic Unit of Medical Oncology, IRCCS San Martino Polyclinic Hospital, Genoa, Italy;2. Pathology Unit, IRCCS San Martino Polyclinic Hospital, Genoa, Italy;3. Department of Internal Medicine and Medical Specialties (DIMI), School of Medicine, University of Genoa, Genoa, Italy;4. Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy |
Abstract: | BackgroundOverexpression of periostin (POSTN) is associated with prostate cancer (PCa) aggressiveness. We investigated the prognostic significance of POSTN expression in tumor biopsy samples of patients with PCa.MethodsWe scored POSTN expression by immunohistochemistry analysis on 215 PCa biopsy samples using an anti–POSTN-specific antibody. A total immunoreactive score (T-IRS) was calculated by adding the POSTN staining scores of stromal and epithelial tumor cells. Prostate-specific antigen (PSA) progression/recurrence-free survival (PFS), radiographic progression/recurrence-free survival (rPFS), and overall survival (OS) were the study end points.ResultsA total of 143 patients received therapy with radical attempt, whereas 72 had locally advanced or metastatic disease and received hormone therapy alone. Median T-IRS was 9 and 12 (range, 0-20), respectively (P = .001). Overall, we found a weak positive correlation of T-IRS with prebiopsy PSA levels (r = 0.166, P = .016) and Gleason score (r = 0.266, P < .000). T-IRS ≥ 8 independently predicted for shorter PSA-PFS and OS (hazard ratio [HR] [95% confidence interval (CI)] ≥ 8 versus < 8: 1.50 [1.06-2.14], P = .024 and 1.92 [1.20-3.07], P = .007, respectively). In the subgroup analysis, the association between T-IRS and patient outcome was retained in patients who received therapy with radical attempt (HR [95% CI] ≥ 8 vs. < 8: rPFS: 2.06 [1.18-3.58], P = .01; OS: 2.36 [1.24-4.50], P = .009) and in those with low to intermediate Gleason scores (HR [95% CI] ≥ 8 vs. < 8: PSA-PFS: 1.65 [1.06-2.59], P = .028; rPFS: 2.09 [1.14-3.87], P = .018; OS: 2.57 [1.31-5.04], P = .006).ConclusionPOSTN T-IRS on PCa biopsy samples independently predicted the risk of recurrence, progression, and death in patients with localized disease and in those with low to intermediate Gleason scores. |