Treatment of oropharyngeal squamous cell carcinoma with IMRT: Patterns of failure after concurrent chemoradiotherapy and sequential therapy

Background: The optimal management of oropharyngeal squamous cell carcinoma (OPSCC) is controversial. Modern radiotherapy typically employs intensity-modulated radiation therapy (IMRT), and herein, we report the Dana-Farber Cancer Institute (DFCI) experience with IMRT-based treatment of OPSCC. Design: Retrospective study of all patients treated at DFCI for OPSCC with definitive or adjuvant IMRT between 8/04 and 8/09. The primary end point was overall survival (OS); secondary end points were locoregional control (LRC) and freedom from distant metastases (FFDM). Propensity score matching was used to create concurrent chemoradiotherapy (CCRT) and sequential therapy (ST) cohorts equally balanced for patient and disease characteristics. Results: One hundred and sixty-three patients were included with 75% presenting with stage IV disease. Fifty-six patients (34%) were treated with ST. The three-year actuarial OS, LRC, and FFDM rates for the entire cohort/ST subset were 86%/89%, 86%/87%, and 88%/93%, respectively. There were no differences in OS, LRC, or FFDM between CCRT and ST in the propensity-matched cohort. Conclusions: IMRT was associated with excellent OS, LRC, and FFDM. Although the results following ST were superb, there was no obvious benefit to ST after adjustment for selection bias. We recommend that ST be reserved for medically fit patients with a high risk of distant metastases.