Outcomes of oral cavity cancer patients treated with surgery followed by postoperative intensity modulated radiation therapy

•We report the outcomes for oral cancer patients treated with postoperative IMRT.•5-year locoregional control and overall survival rates were 76% and 57%, respectively.•Tumors with >1.5 cm depth of invasion had significantly higher risk of local failure.•Positive neck nodes and lymphovascular invasion were predictors of poorer survival.•Disease outcomes did not appear compromised by the use of IMRT.

ObjectivesAlthough treatment paradigms have not changed significantly, radiotherapy, surgery, and imaging techniques have improved, leading us to investigate oncologic and survival outcomes for oral cavity squamous cell cancer (OCSCC) patients treated with surgery followed by postoperative IMRT.Material and methodsRecords of patients with pathological diagnosis of OCSCC treated between 2000 and 2012 were retrospectively reviewed. Patients' demographic, disease, and treatment criteria were extracted. Kaplan-Meier method was used to calculate survival curves.ResultsTwo hundred eighty-nine patients were analyzed. Median follow-up was 35 months. Two hundred sixty-eight had neck dissections (93%), of which 66% had nodal involvement, and 51% of those positive dissections had extracapsular extension. Forty patients received induction chemotherapy and 107 received concurrent chemotherapy. Median dose to high risk clinical target volume was 60 Gy/30 fractions. The 5-year locoregional control and overall survival rates were 76% and 57%, respectively. Tumors with >1.5 cm depth of invasion had significantly higher risk of local failure compared with ≤1.5 cm (p < 0.001). In multivariate analysis, positive and no neck dissection (p = 0.01), positive lymphovascular invasion (p = 0.006) and >1.5 cm depth of invasion (p = 0.003) were independent predictors of poorer survival.ConclusionsDisease outcomes were consistent with historical data and did not appear compromised by the use of IMRT.