Prognostic significance of perineural invasion and lymphovascular invasion following robot-assisted radical prostatectomy with negative surgical margins: a retrospective study from a high-volume center.

PURPOSE

Perineural invasion (PNI) and lymphovascular invasion (LVI) represent tumor escape mechanisms at radical prostatectomy (RP). We assessed their prognostic significance for biochemical recurrence (BCR) following complete resection.

METHODS

We analyzed 10,471 men with negative surgical margins after RP, stratified into three groups based on pathological PNI and LVI status: Group 1 (PNI-/LVI-, n = 1,925), Group 2 (PNI+/LVI-, n = 7,849), and Group 3 (LVI+, n = 697; 14 with PNI-/LVI + and 683 with PNI+/LVI+). The cumulative probability of BCR (PSA > 0.2 ng/mL after initial undetectable level), cancer-specific mortality, and all-cause mortality were compared using Kaplan-Meier curves and log-rank tests. Multivariable Cox regression adjusted for age, race, comorbidity, PSA at biopsy, final grade group, pathological T and N stage, and tumor diameter.

RESULTS

The median follow-up was 60 months (IQR: 18-108). Pathological N1 disease was more frequent in Group 3 (5.7%) than in Group 1 (0.1%) and Group 2 (0.3%). Compared with Group 1, the unadjusted hazard ratios (HRs) for BCR were 6.07 (95% CI: 4.30-8.56) in Group 2 and 23.4 (95% CI: 16.3-33.6) in Group 3; adjusted HRs were 2.51 (95% CI: 1.76-3.58) and 3.79 (95% CI: 2.55-5.53), respectively. Mortality outcomes were comparable across groups, both before and after the adjustment.

CONCLUSION

Our study demonstrated that the combination of PNI and LVI independently predicted BCR following complete resection. Their integration into postoperative risk assessment may improve BCR prediction and guide individualized follow-up planning. Longer follow-up is required to draw definitive conclusions regarding their impact on mortality outcomes.