Xerostomia-related quality of life for patients with oropharyngeal carcinoma treated with proton therapy.

Abstract

PURPOSE\nWe report longitudinal patient-reported quality-of-life (QoL) outcomes related to xerostomia in patients with oropharyngeal cancer treated with intensity-modulated proton therapy (IMPT).\n\n\nMATERIALS AND METHODS\nPatients treated from May 2012 through December 2016 at a single institution for AJCC7 stage III-IV, M0 oropharyngeal cancer were given the 15-item Xerostomia-Related QoL Scale (XeQoLS) before, during, and for up to 2\u202fyears after treatment. We evaluated the evolution of xerostomia-related QoL over that time, and examined potential associations between those measures with clinical characteristics.\n\n\nRESULTS\nSixty-nine patients had XeQoLS scores at baseline and at least once either during or after treatment. The mean (±SD) XeQoLS score (0-4) was 0.24\u202f±\u202f0.57 at baseline. Subsequent scores were 2.00\u202f±\u202f1.01 at 6\u202fweeks on treatment, and 1.03\u202f±\u202f0.76, 0.97\u202f±\u202f0.78, 0.82\u202f±\u202f0.69, and 0.70\u202f±\u202f0.75 at 10\u202fweeks, 6\u202fmonths, 1\u202fyear, and 2\u202fyears after treatment, respectively. All were statistically different from baseline (p\u202f<\u202f0.001). Univariate analyses demonstrated associations between XeQoLS score and time (p\u202f<\u202f0.0001 for each interval), baseline XeQoLS score (p\u202f<\u202f0.0001), stage (p\u202f=\u202f0.008), N status (p\u202f=\u202f0.006), and mean oral cavity dose (p\u202f=\u202f0.038), but not for age, sex, T status, receipt of chemotherapy, smoking history, disease site, laterality of neck irradiation, mean parotid dose, or mean submandibular dose. Multivariate analysis suggested that baseline XeQoLS scores, phase of treatment, and N status were associated with XeQoLS scores measured during treatment and recovery.\n\n\nCONCLUSIONS\nPatients receiving IMPT reported the greatest xerostomia-related QoL impairment at 6\u202fweeks on treatment, with a 49% improvement by 10\u202fweeks after treatment; however, XeQoLS scores remained above baseline after 2\u202fyears. As we aim to establish the value of IMPT in oropharyngeal tumors to de-intensify treatment over conventional therapy, these data help inform discussions about xerostomia-related quality of life for patients with oropharyngeal cancer treated with IMPT.