The prognostic value of inducible nitric oxide synthase in local prostate cancer

Objective To compare the clinical and histological data from patients with prostate cancer with the results of the immunohistochemical analysis of ind ucible nitric oxide synthase (iNOS), and thus determine the prognostic valu e of iNOS. Patients and methods The study included 82 patients (mean age 64.6 years, S D 6.1) with local prostate cancer treated by radical prostatectomy in two F innish hospitals. Their mean (SD) follow-up was 3.3 (2.2) gears. An immunoh istochemical method was used to detect the expression of iNOS in these spec imens. and the expression graded according to staining intensity as none, w eak or strong. Results There was weak or strong expression of iNOS in 25 (31%) and 56 (68% ) of the patients, respectively, and one specimen was negative for iNOS. St rong expression of iNOS was related to high a preoperative prostate specifi c antigen (PSA) level (P=0.006) and high pT classification (P<0.001), but n ot to nodal status, grade, seminal vesicle or capsular invasion, surgical m argin status, perineural infiltration, tumour infiltrating lymphocytes or p roliferation rate of cancer cells. A PSA failure was detected in 29 patient s but was not predicted by iNOS expression. A Cox multivariate analysis sho wed that surgical margin positivity, seminal vesicle involvement and number of tumour infiltrating lymphocytes predicted the PSA failure. Conclusion A high expression of iNOS was related to a high pT classificatio n and the preoperative PSA level but not to other established prognostic fa ctors: iNOS expression was not a predictor of PSA failure in patients with local prostate cancer.