More lymph node dissection improves survival in patients with newly diagnosed lymph node-positive penile cancer

Purpose For patients with lymph node-positive (LN+) penile cancer, the optimal extent of lymph node dissection (LND) is currently not established. We aimed to reveal the potential association between survival and the number of LND in patients with newly diagnosed LN + penile cancer. Methods Patients with LN + penile cancer diagnosed between 2004 and 2015 were identified using the SEER database. The relationships between the number of removed lymph nodes and overall survival (OS), all-cause mortality (ACM), cancer-specific mortality (CSM), and 5-year mortality were tested. Kaplan–Meier curves as well as univariate and multivariable cox regression were used to further analyze disparities in mortality and survival. Results Among 599 eligible patients with LN + penile cancer, 527 (88.0%) received surgery and 72 (12.0%) did not. Compared with those who had not received surgery, patients receiving surgery had longer overall survival (28.31 ± 30.84 versus 16.69 ± 21.68 months) and longer median survival (15.00 versus 8.00 months) times. Univariate analyses demonstrated the number of LND to be an independent factor. Multivariable Cox regression analyses suggested that the ≥ 8 removed lymph nodes predicted a lower ACM rate (hazard ratio (HR) = 0.48, 95% CI 0.38–0.61, p