PSCA, Cox-2, and Ki-67 are independent, predictive markers of biochemical recurrence in clinically localized prostate cancer: a retrospective study

Abstract

Prostate cancer is the second most common male cancer, with half of all patients going on to develop metastases. To better identify patients at high risk for prostate cancer progression and reduce prostate cancer-related mortality, improved prognostic factors are required. In this study, we used immunohistochemistry (IHC) to determine the prognostic values of multiple tissue biomarkers in hormone-naοve prostatectomy specimens of prostate cancer. Using 510 prostatectomy specimens collected between 2002 and 2012, IHC analysis was performed for Cerb-2, Cyclin D1, VEGF, EGFR, Rb, PSCA, p53, Bcl-2, Cox-2, PMS2, and Ki-67 on formalin-fixed paraffin-embedded sections. The Cox proportional hazard model was used to determine the predictive risk factors for biochemical recurrence (BCR) of prostate cancer. During a median 44-month follow-up, 128 (25.1%) patients developed BCR. A multivariate regression analysis revealed that Ki-67 (hazard ratio [HR]: 1.60, P = 0.033), PSCA (HR: 0.42, P < 0.001), and Cox-2 (HR: 2.05, P = 0.003) were the only significant prognostic tissue markers of BCR. Resection margin status (HR: 1.67, P = 0.010), pathologic pT0/1/2 stage (vs pT3/4; HR: 0.20, P = 0.002), preoperative PSA levels (HR: 1.03, P < 0.001), biopsied (HR: 1.30, P = 0.022) and pathologic (HR: 1.42, P = 0.005) Gleason scores, and prostate size (HR: 0.97, P = 0.003) were significant clinicopathologic factors. The expression of Ki-67, PSCA, and Cox-2 biomarkers along with other clinicopathologic factors were prognostic factors for BCR in patients with clinically localized prostate cancer following radical prostatectomy.

Figure 1

Immunohistochemical staining images (×100) of Cox-2, PSCA, and Ki-67 markers in prostatectomy specimens. (a) Cox-2. The apical portion of cytoplasm is positive to Cox-2 staining. (b) PSCA. The tumor cells are exhibited immunostaining primarily in the nucleus. (c) Ki-67. The immunoreactivity is noted in the nucleus.