噴門癌の定義に関するわれわれの見解

Definition of Cardiac Cancer

　従来，噴門癌と称されていた癌は，胃癌研究会による胃癌取扱い規約で“胃上部癌（C領域の癌）”の中に総括されるようになり¹⁾²⁾，食道胃接合部を跨る癌を下部食道噴門癌としてC＜E，C＝E，C＞Eの3群に分けて³⁾論じられるようになった．しかし，やはりこれら胃上部癌の中でも噴門腺領域に発生したと考えられる癌と他の部位（胃底腺領域）の癌とは種々の点で異なるものと思われる^4)～6)．このような観点から最近，西ら⁷⁾によって噴門癌に関する定義の提唱がなされ，第30回胃癌研究会では癌の中心が食道胃接合部の上下2cm以内に存在するものとして，その特性についての検討が行われた．

　しかし，いずれもその定義付けに明らかな根拠を挙げているものはなく，癌の中心点の決め方についても具体的な方法を明示しているものは見当たらない．数年来，噴門癌に関するこれらの問題点について，X線学的，内視鏡学的および病理組織学的検索など，種々の面から検討を加えてきたので，今回は主として噴門癌の定義に関するわれわれの見解を述べてみたい．

　The term “cardiac cancer” has been used by many reporters to define the cancer whose center is located within 2 cm from the functional border between esophageal and gastric mucosa. However, there has been no report describing the evidence for the difinition. On the other hand, determination of the cancerous center generally is not based on concrete criteria.

　(1) Clips were fixed on the esophageal gastric mucosal junction (EGJ) under endoscopy in order to check the locations of the EGJ and the cardia. Fixed clips were observed at 0.5 cm above the cardia on x-ray film.

　(2) In the 61 cases experienced from January to December 1979 EGJ was observed from both esophageal and gastric views. From the esophageal view, the EGJ was always seen above the gastric orifice. From the gastric view, it was seen in only 3.3% of the cases.

　(3) Resected specimens contraining EGJ (23 esophageal cancers and 10 gastric cancers) were investigated histologically. The cardiac gland area was located in the range of 0.5 cm above and 1.5 cm below the EGJ.

　(4) A cancer of gravity for a paper model of the cancerous lesion was determined as the cancerous center. The relationship between the distance of the center from the EGJ and the degree of cancer invasion into the esophageal and gastric walls was reviewed. The cancer whose center was within 1.5 cm from the EGJ always invaded the cardia.

　The results indicate that cardiac cancer is defined as the cancer whose center is located between 1 cm above and 2 cm below the EGJ.