Tumor-Infiltrating Lymphocytes in Resected Esophageal and Gastric Adenocarcinomas Do Not Correlate with Tumor Regression Score After Neoadjuvant Chemotherapy: Results of a Case-Series Study

Abstract

Background/Objectives: Adenocarcinomas of the esophagogastric junction and stomach present clinical entities with significant cancer-related morbidity and mortality, often requiring multimodal treatments. Preoperative chemotherapy, mainly the FLOT regimen, is increasingly being utilized in the neoadjuvant setting for the treatment of these malignancies, with varying degrees of tumor response. Methods: We conducted a retrospective, single-institution review on 75 patients operated on for adenocarcinoma of the esophagogastric junction and stomach after neoadjuvant FLOT. We investigated whether tumor response correlates with disease response in lymph nodes examined on surgical specimens. We also investigated the role of tumor-infiltrating lymphocytes (TILs) in correlation with primary tumor response and disease response in lymph nodes on pathological specimens. Results: Our results suggest that TILs correlate in a differential manner with regards to primary tumors versus lymph nodes, thus suggesting that there are different biologic processes in place. Conclusions: Our results provide unique evidence on tumor-infiltrating lymphocytes in the adenocarcinoma histology of the esophagogastric junction and stomach and might be important for further studies.