A Prospective Study of Chemoradiotherapy as Primary Treatment in Patients With Locoregionally Advanced Penile Carcinoma

Abstract

Neoadjuvant chemotherapy followed by surgery for locoregionally advanced penile carcinoma (LAPSCC) is associated with severe toxicity and a 1-year survival probability of ∼50%. We aimed to evaluate the safety and efficacy of chemoradiotherapy (CRT) as the primary treatment for LAPSCC and the association of high-risk human papillomavirus (hrHPV) with the outcome. This was a prospective, single-center, single-arm study of CRT in LAPSCC, defined as a large/inoperable primary tumor, large palpable nodes, suspicion of extranodal extension or pelvic nodal involvement, and no distant metastases. CRT consisted of 49.5 Gy (33×1.5 Gy) on affected inguinal and pelvic areas combined with intravenous mitomycin C on day 1 and capecitabine on radiation days. Primary tumors and positron emission tomography/computed tomography-positive deposits received a boost of 59.4 Gy (33×1.8 Gy). The response was evaluated by 18F-fluorodeoxyglucose positron emission tomography/computed tomography. If feasible, patients with residual/recurrent disease underwent salvage surgery. The primary endpoint was 1-year progression-free survival (PFS), reached when 1-year PFS was ≥50%. Other endpoints were 2-year PFS, overall survival, and toxicity rates. Kaplan-Meier survival curves were compared using the log-rank test. Thirty-three patients were included: 29 (88%) with stage IV disease (T4 any-N M0 and/or any-T N3 M0) and 8 (24%) with hrHPV-positive disease. Median follow-up was 41 months. Thirty-two completed CRT. Eleven (33%) experienced ≥1 grade 3 treatment-related adverse event. There were no grade 4 or 5 treatment-related events. Twenty-four patients (73%) responded, including 13 (39%) complete responses. Nine patients (27%) underwent salvage surgery, and an additional 8 patients underwent later surgery (together 52%). One- and 2-year PFS were 34% and 31%, respectively. One- and 2-year overall survival were 73% and 46%, respectively. No significant difference between patients with hrHPV-positive and -negative tumors was observed. CRT is a viable treatment option for LAPSCC with acceptable toxicity. CRT can result in an enduring response. If patients have residual tumor, salvage surgery is feasible. HrHPV status was not associated with outcomes.