The survival benefit of different lymph node yields in radical prostatectomy for pN1M0 prostate cancer patients: Implications from a population-based study

BACKGROUND AND OBJECTIVES: The extent and survival benefits of lymph node dissection (LND) in radical prostatectomy (RP) for pN1M0 prostate cancer (PCa) patients remained unclear and were controversial. This study aimed to determine the survival benefit of different lymph node yields in RP for pN1M0 PCa patients. METHODS: pN1M0 PCa patients who received RP and LND were identified in Surveillance Epidemiology and End Results (SEER) (2010–2015). Patients were divided into two groups in SEER based on the removal of one to three regional lymph nodes (LND1 group) or four or more regional lymph nodes (LND4 group). Kaplan–Meier methods were used to calculate cancer-specific survival (CSS) and overall survival (OS). RESULTS: In total, 2,200 patients were identified; 264 patients received LND1 and 1,936 patients received LND4. CSS had no significant difference between the LND4 and LND1 groups (101mon vs. 98mon, p = 0.064), and OS was higher in LND4 patients compared with LND1 patients (97mon vs. 93mon, p = 0.024); for patients with Gleason score = 9 or 10 and T3b or T4, 5-year OS was higher in patients undergoing LND4 (80.9%; 95% CI, 79.0–82.8) compared with those undergoing LND1 (67.5%; 95% CI, 60.8–74.2) (p = 0.009). CONCLUSION: More lymph node yield provided better survival for patients with Gleason score = 9 or 10 and T3b or T4, but not for other pN1M0 PCa patients. The extent of LND would be determined after a comprehensive evaluation including Gleason score, tumor stage, and the general condition of the patient.