BMI and PNI as Predictors of Treatment Completion and Survival in Locally Advanced HNSCC Receiving Sequential Chemoradiotherapy

Objective: This study aimed to evaluate the clinical and laboratory factors affecting treatment response and treatment tolerance in patients diagnosed with head and neck squamous cell carcinoma (HNSCC) and treated with chemoradiotherapy (CRT) after three cycles of induction chemotherapy. Method: Patients who were followed up in the oncology clinic between January 2014 and December 2024 and who could not undergo an organ-sparing approach or surgery were analyzed retrospectively. Demographic, clinical, biochemical and inflammatory parameters of the patients were examined. Binary-logistic regression analysis was used for patients who could not complete the treatment due to toxicity, Cox-regression analysis was used to investigate the factors affecting overall survival (OS), and Roc-Curve analysis was used to determine the ideal-cut-off values ​​for blood markers. Results: A total of 93 patients with HNSCC were included in the study. In univariate logistic regression analysis, age ≥60 (p=0.006), presence of comorbidity (p=0.029), body mass index (BMI) <23.25 (p=0.005), poor ECOG performance score (2-3) (p<0.001) and low prognostic nutritional index (PNI) (p=0.011) were found to be significant risk factors for not completing treatment. Multivariate logistic regression of age, BMI, ECOG, and PNI together formed a predictive model for treatment incompletion. In Cox regression analysis, BMI <23.25 (p=0.016), poor ECOG performance score (2-3) (p=0.002), advanced disease stage (p=0.002), and low PNI (<51.1) (p=0.006) were the main risk factors for unfavorable overall survival. Gender, smoking, tumor location, treatment regimen, and hematological parameters had no significant effect on survival and treatment completion. Conclusion: In HNSCC patients who underwent post-induction CRT, nutritional parameters such as BMI and PNI and performance status play a determining role on treatment tolerance and survival. Detailed assessment of nutritional status before treatment may have an impact on treatment success and survival.