Postoperative Radiation Therapy Refusal in Major Salivary Gland Cancers.

Abstract

Major salivary gland cancers (MSGCs) are often treated with primary surgery followed by adjuvant therapy for high-risk pathology. Patients with these cancers may opt out of recommended postoperative radiation therapy (PORT) for many reasons and consequently may suffer worse outcomes. Retrospective cohort study. National Cancer Database. Patients diagnosed with MSGC from 2004 to 2016 were identified, and overall survival and risk factors for refusal of recommended PORT were analyzed based on demographic, socioeconomic, and clinical factors. Multivariable logistic regression and a Cox model were used to conduct the analysis. 211 out of 4704 qualifying patients (4.5%) refused recommended PORT. Multivariable analysis demonstrated increased PORT refusal for age >74 years (odds ratio OR 4.34, confidence interval [CI] [2.43-7.85]), Asian race (OR 2.25, CI [1.10-4.23]), and certain facility types (comprehensive cancer center, OR 2.39, CI [1.08-6.34]; academic research program, OR 3.29, CI [1.49-8.74]; and integrated network cancer program, OR 2.75, CI [1.14-7.7]). N2 stage was associated with decreased PORT refusal (OR 0.67, CI [0.45-0.98]). The 5-year overall survival for patients who received and refused PORT were significantly different at 65.8% and 53.8%, respectively (p < .001). When controlling for several factors, PORT refusal was independently associated with significantly lower overall survival (HR 1.54, CI [1.21-1.98]). Patient refusal of recommended PORT in MSGC is rare, associated with various disease and socioeconomic factors, and may decrease overall survival. Our findings can assist clinicians in counseling patients and identifying those who may be more likely to opt out of recommended PORT.