Risk Stratification of Prostatic Adenocarcinoma Metastatic to the Lymph Nodes

The pathologic nodal staging of prostatic adenocarcinoma is binary for regional lymph nodes. Stages pN0 and pN1 indicate the absence or presence of regional nodal metastasis, respectively, whereas patients with metastasis to nonregional lymph nodes are staged as pM1a. To determine the risk of recurrence of pN1 prostatic adenocarcinoma patients based on the extent of nodal tumor burden. We retrospectively reviewed pN1 patients with prostatic adenocarcinoma managed with radical prostatectomy seen between 2011 and 2019. Kaplan-Meier and Cox regression analyses were performed to compare disease-free survival. Ninety-six patients were included (median [interquartile range] age, 62 years [57-67 years]; 70 of 96 [73%] white). On univariate analysis, age >65 years (P = .008), ≥2 positive regional lymph nodes (P < .001), and a maximum size of the tumor deposit ≥2 mm (P = .004) were significantly associated with an unfavorable outcome. Controlling for age, stage, metastatic deposit size, margin status, and the presence of extranodal extension, patients with ≥2 positive regional lymph nodes were 3.03 times more likely (95% confidence interval, 1.39-6.60; P = .005) to have an unfavorable outcome. Patients with pN1M1a stage showed a disease-free survival similar to that of pN1M0 patients, after controlling for the number of positive regional lymph nodes (P = .36). Overall, pN1 patients with ≥2 positive regional lymph nodes are 3 times more likely to have an unfavorable outcome. The results suggest a benefit in further stratifying patients with metastatic prostatic adenocarcinoma to the lymph nodes into prognostically significant risk categories that could help the treating clinicians tailor subsequent patient follow-up and therapy.