Potential Utility of the Mallampati Score for Prediction of Treatment Compliance and Safety Profiles of Patients With Head and Neck Cancer Undergoing Definitive Concurrent Chemoradiotherapy

Background/Aim: Restriction of mouth opening (RMO) is a common manifestation of head and neck cancer (HNC) and a poor prognostic factor following concurrent chemoradiotherapy (CCRT) of patients. This study aimed to explore whether the Mallampati score, a visual assessment of the distance from the tongue base to the roof of the mouth, can be used as a surrogate for RMO in predicting treatment outcomes in patients with HNC undergoing CCRT. Patients and Methods: A total of 461 consecutive patients who received definitive CCRT for the treatment of locally advanced HNC between August 2016 and December 2017 at Chang Gung Memorial Hospital in Taiwan (Linkou, Keelung, and Kaohsiung branches) were enrolled in this prospective study. Patients were allocated by the pre-treatment Mallampati score of 1 or 2 (n=24) vs. 3 or 4 (n=207) to compare treatment compliance and treatment-related complications. Results: Patients in the Mallampati score of 3 or 4 group had a higher prevalence of betel quid chewing, oral cavity and oropharynx cancers, advanced tumor stage, poorer performance status, and were more likely to receive platinum monotherapy during CCRT. Patients in the Mallampati score of 3 or 4 group had a 2.08-fold (p=0.002) hazard ratio (HR) for overall survival compared to those in the score of 1 or 2 group in the univariate analysis, the difference remained significant in multivariate analysis (adjusted HR=1.61; 95% CI=1.02-2.61; p=0.047). Patients in the Mallampati score 3 or 4 group had a 2.36-fold (95% CI=1.07-5.19; p=0.033) increased likelihood of incomplete chemotherapy, 2.44-fold (95% CI=1.17-5.06; p=0.017) increased likelihood of incomplete radiotherapy, and 1.84-fold (95% CI=1.18-2.87; p=0.007) risk of unexpected hospitalization compared to those with a Mallampati score of 1 or 2 in multivariate analysis. Conclusion: Patients with HNC with higher pre-treatment Mallampati scores had poorer survival outcomes and were at a higher risk of treatment incompletion and treatment-related toxicities when undergoing CCRT. Our results support the utility of Mallampati score as a surrogate for measuring RMO to predict survival outcomes, treatment compliance, and safety profiles in patients with HNC undergoing CCRT.