Claudin 18.2 overexpression in gastric neuroendocrine tumours

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Introduction: Claudin 18.2, is a tissue biomarker physiologically expressed in both healthy gastric mucosa and gastric adenocarcinoma which represents a novel therapeutic target advanced gastric cancer. Various other cancers showed some overexpression of claudin 18.2 opening potential opportunities to agnostic targeted therapy. However, data about claudin 18.2 expression in NENs are poor with only an Eastern study showing higher rate of claudin 18.2 positivity in GEP-NENs, mainly from gastric primary site (27.8%).

Aim(s): The aim of our study is to assess rates of expression of claudin 18.2 in a specific cohort of gastric NET and correlate it with clinicopathological features.

Materials and methods: We conducted a retrospective study (from 2018 to 2023) collecting data of patients with a histologically confirmed diagnosis of NET from gastric primary managed at IEO. Claudin 18.2 analysis was performed on specimens of primary tumours by Ventana CLDN18 (43-14A) assay. Cases with at least ≥75% of cells showing moderate to strong membranous staining (2+ or 3+) were considered CLDN18.2-positive.

Conference:

Presenting Author: Gervaso L

Authors: Gervaso L, Lobrano R, Pisa E, Benini L, Spada F,

Keywords: claudin, gastric NET, biomarker, Neuroendocrine tumour,