Does tumor location affect prostate cancer prognosis?

Abstract

45 Background: Does tumor location affect prostate cancer prognosis? To clarify this question we conducted a retrospective study to characterize the incidence and prognostic significance of tumor location of prostate cancer. Methods: From 2000 to 2017, radical prostatectomy with no neoadjuvant therapy was performed in 916 cases in our hospital. Serial whole mount sections were reviewed to determine the incidence, clinicopathological features and prognostic significance of tumor location in the prostate gland. For the tumor location, we defined the subzones, which were made from subdivision of the McNeal’s zonal anatomy, are shown in Table 1 in detail. The peripheral zone (PZ) is composed of 8 subzones including A1, A2, A3 , M1, M2, M3, M4, M5. The transition zone (TZ) is composed of 5 subzones including T1, T2, T3, T4 and B1. The central zone (CZ) is composed of 3 subzones including M6, B2 and B3. Results: The median age was 67 and PSA was 8.6 ng/ml. The subzonal tumor incidence divided by all cases was the highest in A2, followed by M4, A1, M3, T2 in that order, while the lowest in B3, followed by M6, T4, T3, B1 in that order. The median follow-up time was 67 months. A 5-year PSA failure rate (5Y-PSAFR) was 23%. Among the subzones, the highest 5Y-PSAFR was seen in B3, followed by M6, B2, T4, A3, and the lowest was seen in M4, A2, T2, A1 in that order. A multivariate analysis for PSAF risk among subzones showed that B3 (HR 8.6, p <0.0001) and M6 (HR 3.3, p = 0.03) were the independent high risk subzones. Conclusions: We demonstrated that the cancer incidence and prognosis varies according to the location within the prostate gland. The B3 and M6 around the ejaculatory duct showed the lowest incidence, while these locations also had the highest recurrence risk. [Table: see text]