Abstract
PURPOSE: To determine the utility of the novel CARWL score, which integrates C-reactive protein-to-albumin ratio (CAR) and significant weight loss (SWL), in stratifying the locally advanced nasopharyngeal carcinoma (LA-NPC) patients into significantly different radiation-induced trismus (RIT) risk groups following definitive C-CRT. PATIENTS AND METHODS: This retrospective study analyzed the medical records of 286 LA-NPC patients who received C-CRT between January 2010 and December 2022. The maximum mouth opening (MMO) was measured before the C-CRT, at 1, 3, 6, 9, and 12 months, and every 6 months after that during the follow-up. Additionally, the CAR value just before the commencement of C-CRT and SWL defined as a weight loss > 5% in the preceding six months were documented for each patient. RIT was defined as a MMO ≤ 35 mm. RESULTS: The optimal CAR cut-off was 3.03 (area under the curve: 87.3%; sensitivity: 82.6%; specificity: 80.9%, J-index: 0.635), using receiver operating characteristic (ROC) curve analysis, with RIT incidence being the event. We stratified the patients into three CARWL score groups. CARWL-0: CAR < 3.0 and WL ≤ 5.0% (N = 92), CARWL-1: CAR < 3.0 and WL > 5.0% or CAR ≥ 3.0 (N = 99), and WL ≤ 5.0% and CARWL-2: CAR > 3.0 and WL > 5.0% (N = 95). The incidence of RIT increased significantly across CARWL score groups (8.7% for CARWL-0, 23.2% for CARWL-1, and 44.2% for CARWL-2; P < 0.001). CONCLUSION: The current study indicated that the novel CARWL scoring system is efficient in precisely stratifying LA-NPC patients into distinct RIT risk groups after C-CRT.