An Oral Cavity Carcinoma Nomogram to Predict Benefit of Adjuvant Radiotherapy<alt-title>Oral Cavity Adjuvant Radiotherapy Prediction Model</alt-title>

Abstract

After surgical resection for oral cavity squamous cell carcinoma, adjuvant radiotherapy may be recommended for patients at higher risk for locoregional recurrence, but it can be difficult to predict whether a particular patient will benefit. To construct a model to predict which patients with oral cavity squamous cell carcinoma would benefit from adjuvant radiotherapy. We constructed several types of survival models using a set of 979 patients with oral cavity squamous cell carcinoma. Covariates were age, sex, tobacco use, stage, grade, margins, and subsite. The best performing model was externally validated on a set of 431 patients. The model was based on a set of 979 patients with oral cavity squamous cell carcinoma, including 563 from Memorial Sloan Kettering Cancer Center, New York, New York, and 416 from the Hospital AC Camargo, São Paulo, Brazil. The validation set consisted of 431 patients from Princess Margaret Hospital, Toronto, Ontario, Canada. The primary outcome measure of interest was locoregional recurrence-free survival. The lognormal model showed the best performance per the Akaike information criterion. An online nomogram was built from this model that estimates locoregional failure-free survival with and without postoperative radiotherapy. A web-based nomogram can be used as a decision aid for adjuvant treatment decisions for patients with oral cavity squamous cell carcinoma.