Department of Pathology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
Department of Oncology/Hematology, Kyungpook National University Chilgok Hospital, School of Medicine, Kyungpook National University, Kyungpook National University Cancer Research Institute, Daegu, Republic of Korea.
Pathol Res Pract. 2024 Nov;263:155628. doi: 10.1016/j.prp.2024.155628. Epub 2024 Sep 30.
Poorly cohesive carcinoma (PCC) is a distinct subtype of gastric cancer with limited therapeutic options. This study investigated claudin (CLDN) 18.2 expression status in PCCs using a 43-13 A clone.
We retrospectively collected 178 consecutive surgically resected stage Ⅱ-Ⅲ gastric cancer samples. Tissue microarray blocks were constructed for CLDN18.2 immunohistochemical staining. We studied CLDN18.2 expression and its association with clinicopathologic parameters.
CLDN18.2 positivity (defined by ≥ 75 % of tumor cells showing moderate to strong membranous positivity) was found in 34.8 % of the PCC cases (62/178). Approximately half of the CLDN18.2 positive PCCs demonstrated heterogeneous expression (51.6 %, 32/62). CLDN18.2 positivity was not associated with any clinicopathologic parameters examined. However, CLDN18.2 positivity tended to be more frequent in E-cadherin-positive PCCs (no loss of expression) than in E-cadherin-negative PCCs (loss of expression) (50 % vs. 27.7 %). The CLDN18.2 expression level, represented by the H-score, gradually decreased as the paraffin block storage time increased (P = 0.046). Overall survival and disease-free survival analyses showed no significant difference between CLDN18.2-positive and negative PCCs.
A significant portion of surgically resected PCC specimens showed CLDN18.2 positivity. Additionally, since the expression level of CLDN18.2 gradually decreases with increased paraffin block storage time, reflex testing can be considered at the time of the cancer diagnosis.
低黏附性癌（poorly cohesive carcinoma，PCC）是一种具有有限治疗选择的独特胃癌亚型。本研究使用 43-13A 克隆检测 PCC 中 Claudin（CLDN）18.2 的表达状态。
我们回顾性收集了 178 例连续接受手术切除的Ⅱ-Ⅲ期胃癌样本。构建组织微阵列块进行 CLDN18.2 免疫组织化学染色。我们研究了 CLDN18.2 的表达及其与临床病理参数的关系。
在 178 例 PCC 病例中，发现 CLDN18.2 阳性（定义为≥75%的肿瘤细胞显示中度至强膜阳性）占 34.8%（62/178）。大约一半的 CLDN18.2 阳性 PCC 表现为异质性表达（51.6%，32/62）。CLDN18.2 阳性与所检查的任何临床病理参数均无关。然而，CLDN18.2 阳性在 E-钙黏蛋白阳性 PCC（无表达缺失）中比在 E-钙黏蛋白阴性 PCC（表达缺失）中更为常见（50% vs. 27.7%）。CLDN18.2 的表达水平（以 H 评分表示）随着石蜡块储存时间的增加而逐渐降低（P=0.046）。总生存和无病生存分析显示 CLDN18.2 阳性和阴性 PCC 之间无显著差异。
相当一部分手术切除的 PCC 标本显示 CLDN18.2 阳性。此外，由于 CLDN18.2 的表达水平随着石蜡块储存时间的增加而逐渐降低，因此可以在癌症诊断时考虑进行反射性检测。
