Clinicopathological and Prognostic Relevance of Tumoral Suppression of Tumorigenicity 2 Expression in Patients With Surgically Resected Pancreatic Carcinoma.

BACKGROUND/AIM:The interleukin (IL)-33/suppression of tumorigenicity 2 (ST2) pathway promotes cancer development and remodels the tumor microenvironment. However, the role of tumoral ST2 expression remains controversial in some solid malignancies. In this study, we have investigated the clinicopathological and prognostic relevance of tumoral ST2 expression in patients with resected pancreatic carcinoma after neoadjuvant chemoradiotherapy. PATIENTS AND METHODS:We analyzed data from 76 patients with surgically resected pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy, between 2009 and 2018. Tissue microarrays were constructed and immunohistochemical analysis was performed for ST2. Associations between variables were analyzed using chi-square tests. Disease-specific survival (DSS) and disease-free survival (DFS) were analyzed using log-rank tests. RESULTS:High expression of ST2, which was observed in 43 patients (57%), was more frequent in patients with high T status (p=0.002), lymphatic invasion (p=0.049), and ≤50% of tumor cells destroyed by chemoradiotherapy (p=0.043; Evans grade I-IIA vs. IIB). In stage I patients, DFS was significantly lower in patients with high ST2 expression (median, 10.6 months) than in those with low ST2 expression (median, 43.4 months; p=0.046). CONCLUSION:High tumoral ST2 expression is associated with high T status, lymphatic invasion, and lower histopathological response grade in patients with pancreatic carcinoma after neoadjuvant chemoradiotherapy.