Adjuvant chemotherapy is associated with improved overall survival in pelvic node-positive penile cancer after lymph node dissection: a multi-institutional study.
OBJECTIVES
We determined whether adjuvant chemotherapy (AC) would be associated with improved survival after lymph node dissection (LND) for patients with penile cancer (PeCa) who have positive pelvic lymph nodes (PPLNs).


METHODS
We retrospectively identified patients across 4 centers with penile squamous cell carcinoma who underwent LND from 1978 to 2013 and were found to have PPLNs. Patients who received chemotherapy before surgery or in the presence of recurrent disease were excluded. Cox regression was used to evaluate the association of AC with overall survival (OS), which was estimated using the Kaplan-Meier method. Differences in OS were determined with the log-rank test.


RESULTS
During the study period, 141 patients who underwent LND for PeCa had PPLNs, and 84 of them met inclusion criteria. Median number of PPLNs was 2 (interquartile range [IQR]: 4-7), with 10% of cases occurring bilaterally and 55% having pelvic extranodal extension. AC was used in 36 (43%) patients. Patients who received AC were younger (P = 0.014), had less-aggressive penile tumor pathology (P<0.01), were less likely to receive adjuvant radiation (P<0.01), had less bilateral inguinal disease (P = 0.019), and had more inguinal extranodal extension (P = 0.042). Median follow-up was 12.1 months. Estimated median OS was 21.7 months (IQR: 11.8-104) in patients who received AC vs. 10.1 (IQR: 5.6-48.1) in those who did not (P = 0.048). AC was independently associated with improved OS on multivariate analysis (hazard ratio: 0.40; 95% CI: 0.19-0.87; P = 0.021).


CONCLUSIONS
AC is associated with improved OS in patients with PeCa who have PPLNs after LND. Prospective studies are needed to demonstrate causality.