Comparative effectiveness of induction chemotherapy for oropharyngeal squamous cell carcinoma: A population-based analysis

• We used the National Cancer Database to compare the effectiveness of definitive chemoradiotherapy versus induction chemotherapy for patients with oropharyngeal squamous cell carcinoma.
• There was no difference in survival between these two strategies.
• Induction chemotherapy was associated with a nearly significant survival detriment in patients with human papillomavirus (HPV)-positive disease, but it led to significantly improved survival in individuals with high-risk (i.e. T4/N3) HPV-negative cancer.
• This analysis supports definitive chemoradiotherapy as the standard-of-care, but further research should be performed on induction chemotherapy in poor-prognosis cohorts.

SummaryObjectivesDespite several randomized trials, the optimal chemotherapy paradigm for locally advanced oropharyngeal carcinoma (OPSCC) is controversial. This population-based analysis assessed the overall survival (OS) benefit of induction chemotherapy (IC) for patients with stage III–IVB OPSCC.Materials and MethodsPatients in the National Cancer Database with stage III–IVA-B OPSCC treated with curative-dose radiotherapy and IC or concurrent chemotherapy (CRT) between 2003 and 2011 were eligible. The primary outcome was OS, and secondary endpoints included OS for high-risk (T4 and/or N3 disease) and human papillomavirus (HPV) subsets.ResultsOf the 14,856 analyzed patients, 78% and 22% received CRT and IC, respectively. With a median follow-up for surviving patients of 44 months, the 5-year OS probability for the entire cohort was 66% (66% CRT vs. 64% IC, p = 0.022). Multivariable survival analysis showed no significant difference between CRT and IC (hazard ratio, HR, 0.95 for IC, p = 0.255), and sensitivity analyses to adjust for immortal time bias brought the HR to 1.0 (p = 0.859). There was also no OS difference for high-risk patients. There was a trend in favor of CRT for HPV-positive OPSCC (HR 1.63 with IC, p = 0.064), with a significant OS benefit for HPV-negative, high-risk OPSCC (HR 0.63, p = 0.048).ConclusionFor the vast majority of patients, including HPV-positive individuals, there was no difference in OS with IC, arguing for CRT to remain as the standard therapy. Subset analysis revealed a small cohort of aggressive cancer (T4/N3 HPV-negative) which may benefit from from IC, although selection bias could not be ruled out.