pm胃癌の臨床―当院における統計と病理

Clinical and Statistic Observations on the Intramuscular Cancer of the Stomach and its Pathology

　進行癌ばかりで早期胃癌ともなればはなはだ少ない経験しかなかった筆者は，早期胃癌の手術例が増加するとともに漸くその実態を知るようになったのは，愛知県がんセンターが開設されて1，2年後の頃である．同時にまた病理組織学的検索の結果，癌浸潤がわずかながら既に粘膜下層を貫いて固有筋層にみられたため，早期胃癌の範疇を逸脱して失格するいわば準早期胃癌の症例にもしばしば遭遇するようになった．1968年に入ってこれら失格例を含めてpm癌を検討すると，pm癌はたとえそれが小さい胃癌であっても，長径が2cmをこえるとリンパ節転移はもとより病理組織学的に配列違型度・浸潤度など，癌進展の様相は早期胃癌と比べ大いに趣きが異ることに注目した．また症例を重ねるに従い，術後経過の様相も漸次明らかになって，早期胃癌・pm癌などまだ癌浸潤が漿膜に及ばない症例では，その予後を支配する重要な因子は血行性転移殊に肝転移であることを知って，筆者はpm癌に対する一層の関心をもった．胃癌診断の技術が進歩し普及するに従って，早期胃癌・pm癌など予後の良い手術症例が漸次増加するであろう折柄，これらの問題は今後われわれ臨床外科医にとってはなはだ大切であると考えた．1973年紀藤は当院臨床検査部の協力を得てpm癌症例を改めて連続切片で検索し検討した．その結果は数回に亘って学会または誌上に報告したが，このたび編者から標題にみるような課題が与えられたので，愛知県がんセンター病院外科第3部で経験した10年間のpm癌症例の大要を報告しようと思う．

　During the past 10 years we have come across 199 cases of pm gastric cancer out of 1,854 gastric resections for cancer. Clinical as well as histologic examinations of these pm cancers showed that this variety had several features of its own irrespective of its relatively small size with no connection to P factor.

　1. About half the number of pm cancer were less than 5 cm in diameter. Lesions even under 2 cm were seen in 28 cases.

　2. Lymph node metastasis in pm cancer was of high percentage (43.7%). Even small cancers less than 2 cm showed a metastasis rate of 28.6 per cent. Vascular invasion was observed in 31.5 per cent.

　3. The results of surgery were favorable. The 5-year-survival rate was 76.2 per cent, but it leaves little room for optimism as it differs significantly from that of early cancer, which is at present as high as 94 per cent. The size of cancer lesion seemed to alter more or less the 5-year-survival rate.

　4. Lymph node metastasis greatly affects the prognosis. In the group n₀ were the end results as good as 87.4 per cent, approaching to those of early cancer. In the n_{1 (+)} group the rate was onlyd 62.1 per cent, and in n_{2 (+)} 53.7 per cent.

　5. The most important factor that sways the prognosis of pm cancer was the absence or presence of liver metastasis. There were 30 fatal cases of recurred cancer. Liver metastasis was recognized in 11 out of 22 cases that had shown definite patterns of metastasis. Lung involvement was also seen in one case. Attention should also be paid to death due to carcinomatous peritonitis arising from peritoneal dissemination of cancer.

　As for early gastric cancer, the number of surgical correction for pm gastric cancer is ever increasing. Pm cancer furnishes us not only with useful materials for the analysis of prognosis for gastric cancer but also with some helpful hints for making the surgical results even better.