Elevated PGE2 and COX-2 expression in villous adenoma: Implications for electrolyte depletion syndrome

The present study aimed to clarify the role of prostaglandin E2 (PGE2) signaling in the pathogenesis of electrolyte depletion syndrome (EDS) in colorectal villous adenomas (VAs), which are characterized by excessive mucus secretion and higher malignant potential compared with tubular adenomas (TAs). A retrospective analysis was conducted on 40 colorectal adenoma cases (20 VAs and 20 TAs) resected between January 2011 and September 2021. Clinicopathological factors such as age, sex, tumor location and size were compared. In addition, immunohistochemical staining for PGE2, COX-1 and COX-2 was performed, and the percentage of positive glands was quantified. Associations between PGE2 and COX isoform expression were then analyzed. The results revealed that VAs were more prevalent in female patients (P=0.022) and exhibited a significantly larger tumor size than TAs (21.3±22.5 mm vs. 9.6±7.8 mm, P=0.018). Furthermore, PGE2 and COX-2 expression were significantly elevated in VAs compared with in TAs (P<0.001 and P=0.022, respectively), whereas COX-1 levels were similar. In VAs, PGE2 expression was weakly-to-moderately associated with COX-1 and associated with COX-2 (trend), whereas no associations were observed in TAs. In conclusion, PGE2 upregulation may contribute to EDS in VAs, underscoring the need for early recognition and targeted therapeutic approaches.