(0710) Predictors of Weight Loss in Patients Undergoing Radiation for HPV-Related Oropharyngeal Squamous Cell Carcinoma

Introduction: Radiotherapy is commonly included in treatment of human papillomavirus-related oropharyngeal squamous cell carcinoma (HPV+OPSCC). Radiation contributes to xerostomia, dysgeusia and mucositis and inhibits oral alimentation considerably, thereby contributing to weight loss. Critical weight loss (CWL) has been suggested as a negative prognostic factor in head and neck cancer. We examine the prevalence of CWL among patients undergoing radiotherapy for HPV+OPSCC and to identify predictors of weight loss.

Methods: Retrospective series of adult patients who received radiotherapy as part of their treatment package for nonrecurrent, nonmetastatic HPV+OPSCC between 2018 and 2021 at a single center. Patients losing >5% total body weight (TBW) during radiation or >7.5% 6 months post-treatment were considered to have CWL. A multivariable regression model investigated potential predictors of percentage TBW lost. Propensity score matching estimated the average marginal effect of prophylactic gastrostomy on percentage TBW lost while accounting for covariates.

Results: This study included 145 patients. Of them,109 patients (75.2%) had T 0-2 classification tumors, and a plurality of tumors were in the base of tongue (n = 58, 40%). Multimodality treatment was used in 139 (95.9%) patients, including 52 (35.9%) with surgery and 103 (71%) with chemotherapy. The average patient lost 8.4 kilograms (8.8% TBW) during radiation, and 126 patients (86.8%) experienced CWL. 54 patients (37.2%) required a gastrostomy. Multivariable regression identified male sex and chemotherapy as predictors of increased TBW lost and being on a restricted diet prior to treatment reduced TBW lost. Propensity score matched analysis included 28 matched pairs and demonstrated an absolute reduction of TBW lost by 3.1% (CI 0.3-5.9%, p = 0.032) and a reduction in the rate of CWL by 7.1% (CI 4.7-9.5%, p < 0.001) in patients with prophylactic gastrostomy.

Conclusions: Patients undergoing radiation for HPV+OPSCC are at high risk of CWL. Prophylactic gastrostomy may have a protective effect on weight loss and may be considered in patients deemed high-risk for CWL.