dMMR型胃癌の切除および生検検体の臨床病理学的，および組織学的検討

Clinicopathological and Histological Analyses of Resected and Biopsy Specimens of Gastric Cancer with Deficient Mismatch Repair

要旨●dMMR型胃癌の組織学的特徴を明らかにするために，胃癌切除検体202例および生検検体70例を対象に臨床病理学的因子および組織学的因子を検討した．切除検体でdMMR型胃癌を反映する臨床病理学的因子は性別，年齢であり，組織型は髄様癌が多くみられた．組織学的因子は乳頭管状構造，TILおよびCD8陽性細胞数であった．生検検体においてはTILがdMMR型胃癌を反映した．また，切除検体および生検検体の多変量解析結果から，dMMR型胃癌の予測式を切除検体，生検検体ごとに算出した．本稿で検討した切除検体および生検検体の臨床病理学的・組織学的特徴，dMMR型胃癌の予測式はdMMR型胃癌の診断向上につながると思われた．

　This study aimed to evaluate the clinicopathological and histological factors of GC（gastric cancer）with dMMR（deficient mismatch repair）in 202 resected and 70 biopsy specimens. The significant clinicopathological factors identified in the resected dMMR-type GC specimens were gender and age. Histological examination showed that medullary carcinoma was frequently observed in the resected specimens. The significant histological factors identified in the resected specimens were papillary tubular structure, TILs（tumor-infiltrating lymphocytes）, and CD8-positive cells. In the biopsy specimens of dMMR-type GC, TILs were the significant histological factor. We performed multivariant analysis of the extracted clinicopathological findings and calculated the prediction formula for each resected and biopsy specimen of dMMR-type GC on the basis of the results. The findings of this study will contribute to the improvement of the diagnostic efficiency of dMMR-type GCs.