The Impact of Prostate Cancer Zonal Origin on Pathological Parameters at Radical Prostatectomy and Subsequent Biochemical Failure.

PURPOSE: We assessed the impact of prostatic zone tumor origin on pathological prognostic features and subsequent biochemical outcomes after radical prostatectomy. MATERIALS AND METHODS: A total of 7,051 patients who underwent radical prostatectomy between September 1998 and December 2016 in Western Australia were divided into a high grade group, defined as Gleason sum 4 + 3, 8 and 9 or greater and ISUP (International Society of Urological Pathology) groups 3, 4 and 5, and a low grade group, defined as Gleason sum 6 or less and 3 + 4, and ISUP groups 1 and 2. The t-test and the Pearson chi-square test were used to evaluate differences between transition zone and peripheral/central zone cancer. The Kaplan-Meier method with the log rank test was used to determine differences in biochemical recurrence-free survival at 5 years in patients with high grade disease. Univariate and multivariable Cox proportional hazard regression analyses were performed. Model calibration was determined by the internal validation method. RESULTS: High grade transition zone cancer was associated with significantly increased prostate specific antigen, tumor volume and incidence of positive surgical margins but a lower incidence of intraductal carcinoma, extraprostatic spread, seminal vesicle invasion, lymph node involvement and biochemical failure after radical prostatectomy. Patients with low grade prostate cancer had excellent biochemical recurrence-free survival regardless of tumor origin. The high grade multivariable model had a c-index of 0.78 and improved predictive accuracy, particularly for high grade transition zone disease. CONCLUSIONS: Transition zone tumor origin independently and positively impacts biochemical outcomes of high grade prostate cancer. A high grade postoperative prognostic model including transition zone tumor origin as an independent predictor was developed and predictive accuracy was significantly improved in patients with high grade, transition zone disease.

Reliable identification of transition zone prostatic adenocarcinoma in preoperative needle core biopsy.

Prostatic adenocarcinomas arising within the transition zone (Tz) are distinct from peripheral zone (Pz) tumors as regards biological aggression and mechanism of extraprostatic extension. Reliable biopsy identification of Tz tumors would allow targeted surgical approaches more likely to preserve erectile function without compromising surgical margins. Previous studies have demonstrated the presence of eosinophilic cytoplasmic granules (prostate secretory granules, or PSGs) after glutaraldehye fixation, with apparent depletion in neoplasia. We investigated PSG content, columnar cells, pale cytoplasm, and luminal secretions of both Pz and Tz tumors in 44 radical prostatectomies (RPs) and 135 biopsies fixed with gluteraldehyde-based fixative. Retention of PSG is characteristic of Tz carcinoma and infrequently seen in Pz tumors, and a combination of PSG greater than 30% with either columnar cells, pale cells, or secretions in biopsies is a reliable marker for Tz origin. When these criteria were prospectively applied to 3929 cases with follow-up RP, 510 Tz tumors were correctly identified on biopsy (sensitivity, 21.4%; specificity, 97.4%). Biopsy-identified Tz tumors had higher volumes (mean, 3.48 versus 1.81 cm(3); P < .001) and higher rates of margin positivity (22.5% versus 17.5%; P = .008) than did Tz tumors not identified preoperatively. Mean Tz tumor length in biopsies was 2.0 mm, with no correlation between tumor volume at RP and tumor length on biopsy. Tz tumors are reliably identified on biopsy, based on a combination of PSG retention with either columnar cells, pale cells, or secretion. Biopsy-identified Tz tumors may not be suitable for active surveillance because of an associated high probability of large tumor volume and increased risk of positive margins at RP.