Adjuvant Radiotherapy Is Not Supported in Patients With Verrucous Carcinoma of the Oral Cavity

Objective: To analyze the impact of adjuvant radiation therapy (RT) on overall survival (OS) and disease-specific survival (DSS) in patients with verrucous carcinoma (VC) as compared to squamous cell carcinoma (SCC) of the oral cavity. Study Design: Cross-sectional population analysis. Methods: Cases of nonmetastatic VC/SCC of the oral cavity were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (1988-2013). Kaplan-Meier survivals, stratified according to T stage, were compared between VC and SCC for treatment with or without adjuvant RT. Results: A total of 18,819 VC/SCC cases were identified. There were 581 (3.1%) VC (mean age 69.6 years, 48.9% female) versus 18,238 (97.0%) SCC (mean age, 65.3, 37.1% female) patients. Verrucous carcinoma patients receiving surgery alone (N = 539) demonstrated a trend toward improved OS versus VC patients receiving surgery and RT (N = 40) (117.0 vs. 71.4 months, respectively, P = 0.119). There was a statistically significant improvement in DSS in VC patients receiving surgery alone (217.2 vs. 110.9 months, P = 0.05). Verrucous carcinoma patients treated with adjuvant RT demonstrated a trend toward a worse OS (71.4 vs. 93.0 months, P = 0.992) and DSS (110.9 vs. 162.3 months, P = 0.275) compared to SCC treated with adjuvant RT, suggesting a different biology and radiosensitivity between VC and SCC. Conclusion: Verrucous carcinoma treated with adjuvant RT had a worse OS and DSS compared to both VC treated with surgery alone and SCC treated with surgery and adjuvant RT. Consideration should be given to surgical re-section rather than adjuvant RT in patients with positive margins or local recurrence.