Association Between Human Papillomavirus Infection and Outcome of Perioperative Nodal Radiotherapy for Penile Carcinoma

Abstract

BackgroundData on the impact of human papillomavirus (HPV) infection status and outcomes for perioperative treatments for patients with lymph node–involved penile squamous-cell carcinoma (PSCC) are lacking. ObjectiveTo analyze the benefit from perioperative radiotherapy (RT) for PSCC according to HPV infection status. Design, setting, and participantsIn an international multicenter database of 1254 patients with PSCC who received inguinal lymph node dissection (ILND), 507 had suitable clinical information. InterventionILND, with or without chemotherapy or RT for involved lymph nodes. Outcome measurements and statistical analysisKaplan-Meier and restricted mean survival time (RMST) analyses for overall survival (OS) were performed for all patients and after propensity score-matching (PSM; n = 136), for which patient age, histology, type of penile surgical procedure, pathological tumor and nodal stage, ILND laterality, pelvic LND, and perioperative treatment were taken into account when assessing differences between HPV+ and HPV– patients. Finally, we looked at genomic alterations in PSCC using data from the Foundation Medicine database (n = 199) to characterize HPV+ PSCC. Results and limitationsPatients with HPV+ PSCC (n = 86; 17%) had lower clinical N stage (p < 0.001) and inguinal lymph node metastasis density (p < 0.001). Perioperative RT was delivered in 49 patients (9.7%), with the vast majority receiving adjuvant RT (n = 40). HPV+ patients had similar median OS (p = 0.1) but longer RMST than HPV– patients at different time points. Nevertheless, HPV+ patients treated with perioperative RT exhibited longer median OS (p = 0.015) and longer RMST compared to HPV– patients. In the PSM cohorts, HPV+ status remained significantly associated with longer OS after RT. The HPV– PSCC group had a higher frequency of TP53 mutations compared to HPV+ PSCC (75% vs 15%; p < 0.001). The results are limited by the retrospective nature of the data. ConclusionsPerioperative RT was more effective in the HPV+ PSCC subgroup. Reasons for the enhanced radiosensitivity may be related to the lack of TP53 mutations. Patient summaryWe analyzed data from a large multicenter database for patients with penile cancer who had received inguinal lymph node dissection, with or without chemotherapy or radiotherapy. We found that for tumors positive for human papillomavirus (HPV), use of radiotherapy resulted in prolonged survival compared to HPV-negative tumors. On the basis of these results we are inspired to design studies on the use of radiotherapy in HPV-selected patients.