Association of Time between Surgery and Adjuvant Therapy with Survival in Oral Cavity Cancer

Abstract

Objective The National Cancer Center Network recommends starting radiation therapy within 6 weeks after surgery for oral cavity squamous cell carcinoma (OCSCC), but there is limited evidence of the importance of the total time from surgery to completion of radiation therapy (package time). We set out to determine if there was an association between package time and survival in OCSCC and to evaluate the impact of treatment location on outcomes. Study Design Retrospective cohort study. Setting Tertiary academic medical center. Subjects and Methods We reviewed the records of patients with OCSCC who completed postoperative radiation therapy at an academic medical center from 2008 to 2016. The primary endpoints were overall survival and recurrence-free survival. Statistical analysis included χ2 tests and Cox proportional hazards regressions. Results We identified 132 patients with an average package time of 12.6 weeks. On multivariate analysis, package time >11 weeks was independently associated with decreased overall survival (hazard ratio, 6.68; 95% CI, 1.42-31.44) and recurrence-free survival (hazard ratio, 2.94; 95% CI, 1.20-7.18). Patients who received radiation therapy at outside facilities were more likely to have treatment delays (90.2% vs 62.9%, P = .001). Conclusions Prolonged package times are associated with decreased overall and recurrence-free survival among patients with OCSCC. Patients who received radiation therapy at outside facilities are more likely to have prolonged package times.