274P - Index tumor location influencing early biochemical recurrence after radical prostatectomy in patients with negative surgical margins

Background

Index tumors are recognized as the most aggressive prostate tumors; however, their clinical implications remain unclear. This study aimed to investigate the occurrence of index tumor localization based on zonal origin and explore the impact of these locations on the prognosis after radical prostatectomy among patients with negative surgical margins.

Methods

In this retrospective, single-center study, a cohort of 1,109 consecutive patients who underwent radical prostatectomy was analyzed. The index tumor was defined as the largest tumor within the prostate gland. Localization was determined using McNeal's zonal origin classification on whole-mount sections. Kaplan-Meier survival curves were employed to assess biochemical recurrence (BCR)-free survival. Univariate and multivariate Cox proportional hazards analyses were conducted to identify predictive factors for early BCR (within 1 year).

Results

Among the 621 patients with negative surgical margins and no adjuvant therapy, index tumors were localized in the transitional zone in 191 patients (30.8%), the peripheral zone in 399 patients (64.3%), and the central zone in 31 patients (5.0%). A total of 22 patients (3.5%) experienced early BCR, and 70 patients (11.2%) experienced overall BCR during a median follow-up period of 61.7 months. Based on index tumor location, the early BCR-free rates were 99.5%, 95.7%, and 83.3% for the transitional, peripheral, and central zones, respectively. Multivariate analysis identified the index tumor in the central zone as an independent predictor of early BCR with negative surgical margins following radical prostatectomy, followed by the pathological grade of the prostatectomy specimen, index tumor in the peripheral zone, and a high prostate-specific antigen level.

Conclusions

This study examined the significance of index tumor location among patients with negative surgical margins after radical prostatectomy. Notably, index tumors situated in the central zone, although infrequent, emerged as the most robust predictors of early BCR. These findings may prompt urologists and patients to reconsider their therapeutic strategies for prostate cancer management.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.