Risk factors for aspiration pneumonia related to postoperative chemoradiotherapy for high-risk head and neck cancer: A supplementary analysis of a phase II/III JCOG1008 trial

6059 Background: A randomized phase II/III trial (JCOG1008) suggested that postoperative chemoradiotherapy (POCRT) with weekly cisplatin is a treatment option for patients with postoperative high-risk locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). Aspiration pneumonia (AP) is one of the most important toxicities associated with CRT. This study investigated the clinical risk factors for AP during and after POCRT. Methods: Patients enrolled in JCOG1008 were analyzed to evaluate the incidence of AP, to identify the clinical risk factors for AP during and after POCRT, and to assess the influence of AP on treatment outcomes. AP was defined as a clinical condition meeting all of the following criteria: (i) patients had both subjective and objective symptoms suggesting pneumonia, (ii) the presence of aspiration was suspected clinically or by endoscopic or video-fluorographic examinations, (iii) no evidence of micro-organisms that cause atypical pneumonia. Analyses were performed by logistic regression model. Results: Of 251 patients who underwent POCRT, 100 patients who underwent laryngectomy was excluded. Among the 151 patients who received POCRT, 93 (61.6%), 85 (56.3%), and 113 (74.8%) developed AP during, after, and overall period of POCRT, respectively. The multivariable analyses identified two independent risk factors for AP occurring during or after POCRT: PS 1 [vs. PS 0; odds ratio (OR) 3.416, 95% CI (1.192-9.789), p = 0.0222] and dysphagia ≥grade 3 (vs. grade 1-2; OR 46.333, 95% CI (2.901-740.080), p = 0.0067). The multivariable analyses also identified two independent risk factors for AP occurring after POCRT: dysphagia ≥grade 3 (OR 3.995, 95% CI (1.538-10.375), p = 0.0045) and reconstruction surgery (OR 3.452, 95% CI (1.616-7.374), p = 0.0014). Charlson comorbidity score ≥4 and the use of sleeping pills at the end of POCRT were marginally associated with the onset of AP after POCRT (OR 2.699, 95% CI (0.919-7.926), p = 0.0708, OR 2.107, 95% CI (0.918-4.837), p = 0.0788, respectively). The occurrence of AP was not significantly associated with overall survival, relapse-free survival, and local relapse-free survival. Conclusions: PS 1, dysphagia ≥grade 3, and prior reconstruction surgery were associated with the onset of POCRT-related AP. Careful attention should be paid to these risk factors for AP in patients with LA-SCCHN undergoing POCRT. Clinical trial information: jRCTs031180135 .