Critical Role of Preoperative Hyperglycemia in Association with GFAT-1 Expression in Resected Pancreatic Cancer.

Abstract

Hyperglycemia is involved in malignant transformation of pancreatic cancer via the hexosamine biosynthetic pathway (HBP). However, few studies have verified this mechanism based on clinical data. This study investigated the complementary effects of hyperglycemia and HBP on pancreatic cancer prognosis using detailed clinical data. The study analyzed data of 477 patients with pancreatic cancer who underwent pancreatectomy between 2006 and 2020. The patients were divided into normoglycemia and hyperglycemia groups based on their HbA1c levels. Immunostaining for glutamine fructose-6-phosphate transaminase-1 (GFAT-1), the rate-limiting enzyme in HBP, CD4, CD8, and Foxp3, was performed to evaluate the association between survival outcomes, HBP, and local tumor immunity. Overall survival (OS) was significantly poorer in the hyperglycemia group than in the normoglycemia group (mean survival time [MST]: 35.0 vs. 47.9months; p = 0.007). The patients in the hyperglycemia group with high GFAT-1 expression had significantly poorer OS than those with low GFAT-1 expression (MST, 49.0 vs. 27.6months; p < 0.001). However, the prognosis did not differ significantly between the patients with high and low GFAT-1 expression in the normoglycemia group. In addition, the patients with hyperglycemia and high GFAT-1 expression had fewer CD4+ (p = 0.015) and CD8+ (p = 0.017) T cells and a lower CD8+/Foxp3+ ratio (p = 0.032) than those with hyperglycemia and low GFAT-1 expression. The patients with hyperglycemia and high GFAT-1 expression levels had an extremely poor prognosis. Furthermore, the tumors in these patients were characterized as immunologically cold tumors.