Abstract 4644: Pretreatment diet, serum carotenoids and tocopherols influence tumor immune response in head and neck squamous cell carcinoma

Background: Tumor infiltrating lymphocytes (TILs) have recently emerged as an important factor in informing treatment decisions for head and neck squamous cell carcinoma (HNSCC). Nevertheless, little is known about the role of modifiable risk factors, such as diet, on TILs. Methods: Immunohistologic expression of CD4, CD8, CD68, CD103, CD104 and FOXP3 were assessed in tissue microarrays from 233 previously untreated HNSCC patients. Associations between these markers and pre-treatment dietary patterns were then evaluated using linear regression models. Logistic regression models assessing the associations between baseline serum carotenoids, tocopherols and TILs were conducted on a smaller subset of 70 patients. Cox proportional hazard models were used to evaluate the joint association between diet and TILs on overall and recurrence free survival. Results: High intake of a Western dietary pattern decreased CD8+ and FOXP3+ infiltrates after adjustment for age, sex and batch (p-value: 0.03 and 0.02, respectively). Multivariate logistic regression models demonstrated significant increases in CD8+ (OR: 2.21; p-value: 0.001) and FOXP3+ (OR: 4.26; p-value: