進行胃癌の内視鏡診断体系update

Updates in Endoscopic Diagnosis of Advanced Gastric Cancer

要旨●胃癌の診療は時代の変遷とともに大きく変化したが，日常診療で進行胃癌に遭遇する機会は多い．進行胃癌の鑑別診断や深達度診断は，病変の肉眼形態に応じて異なってくる．また，範囲診断は術式決定に直結するため，正確な先進部の評価が求められるが，進行癌の側方進展パターンを理解することによって系統的な内視鏡診断が可能になる．一方，生検検体の大半は粘膜部分しか採取されておらず，生検に依存した範囲診断には限界があることを理解すべきである．実際には，内視鏡診断や生検診断では正確な評価が困難な場合もあり，胃X線造影検査などの他のモダリティや術中迅速断端評価を用いるなど柔軟な姿勢が求められる．

　Gastric cancer treatment has considerably evolved. However, advanced gastric cancer is frequently encountered in clinical practice. Therefore, accurate preoperative diagnosis is necessary to select optimal therapeutic interventions. Differential diagnosis and depth estimation are closely associated with the morphology of the lesion. Additionally, accurate determination of the extent of advanced cancer profoundly affects the selection of surgical approach, warranting careful evaluation of lateral tumor extension. A comprehensive understanding of the progression patterns of advanced gastric cancer is crucial for methodical endoscopic diagnosis. Recognizing that the majority of biopsy specimens contain only mucosal tissue is important. Therefore, relying solely on biopsy for a comprehensive diagnosis of cancer extent has significant limitations. Practical scenarios frequently present difficulties in achieving accurate evaluations even with endoscopic and biopsy methods, requiring a flexible approach that incorporates alternative modalities, including gastric fluoroscopy or intraoperative rapid margin assessment.