Claudin 18.2 Expression in Colorectal Mucinous Adenocarcinoma: A Clinicopathological Analysis

Abstract

Background: Colorectal mucinous adenocarcinoma (MAC) is a distinct subtype of colorectal adenocarcinoma characterised by high recurrence rate and limited treatment options. The tight-junction-associated protein claudin 18.2 (CLDN18.2) has emerged as a novel therapeutic target in various solid tumours. This study aimed to assess CLDN18.2 expression in MAC and its clinicopathological association.

Methods: CLDN18.2 expression was immunohistochemically evaluated in a cohort of 91 patients with MAC who underwent surgical procedures between January 2022 and April 2024. Positive CLDN18.2 staining was defined as ≥10% of tumour cells exhibiting ≥1+ membrane staining or any instance of ≥2+ membrane staining.

Results: CLDN18.2 expression was detected in 19.8% (18/91) of the patients with MAC. Positive expression of CLDN18.2 significantly correlated with perineural invasion (P = 0.0235) and lymphovascular invasion (P = 0.0375). CLDN18.2 demonstrated frequent heterogeneous expression in MAC.

Conclusions: In summary, the present study found that CLDN18.2 was positively expressed in MAC, and its overexpression was associated with increased invasive capacity. Therefore, CLDN18.2 is a promising therapeutic target that warrants further investigation in patients with MAC.