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 < 0.001), penile CSM rate (HR = 0.42, 95% CI 0.30-0.57, p < 0.001), and lower 5-year mortality (HR = 0.58, 95% CI 0.47-0.71, p < 0.001).
Conclusions: In patients with newly diagnosed LN + penile cancer, more LND during lymphadenectomy was associated with an improvement in ACM, CSM rate, and 5-year mortality. Therefore, patients with preoperatively LN + penile cancer should undergo LND to have more lymph nodes removed.
Keywords: Lymph node dissection; Lymph node-positive; Penile cancer; SEER; Survival benefits.