X線像，内視鏡像の改善の立場からみた胃癌化学療法

Cytotoxic Chemotherapy for Advanced Gastric Cancer: From the viewpoint of macroscopic improvement on x-ray and gastroscopic views

　従来，胃癌の化学療法の際，原発ないし転移腫瘍が縮小しても一過性で，延命効果につながることは極めて稀であった¹⁾²⁾．そしてまた原発巣がある場合，化学療法によってX線や内視鏡所見の改善をみることは滅多にみられることではなかった．ところが，近年，Futrafulの経口剤，坐剤，5-FUドライシロップによる胃癌の治療が普及するにつれて，形態学的所見の明らかな改善がみられた症例の報告が増えつつある^1)～10)．われわれはこの10年6カ月間，X線，内視鏡，生検所見の変化に注目しながら胃癌の化学療法を実施してきた^1)2)5)10)．その結果，進行癌で3例の癌消失，3例の「早期癌と見まちがえる」ほどの改善，早期癌で1例の消失（本誌1663頁）を経験した．進行胃癌では，この6例ほどではないにしろ客観的に改善したといえる症例では延命効果が認められるようである．一方，固型癌の化学療法の効果判定には，腫瘍の縮小率をもってしようという動きが世界的な傾向である¹¹⁾¹²⁾．しかし，胃癌のように多彩な病像を示す疾患は，触診を中心とした腫瘍の縮小率で効果を論ずるには幾多の問題がある．したがって，ここではわれわれの経験した胃癌治療の実態を明らかにするとともに，実例に即して胃癌の治療効果の判定に当っては，X線や内視鏡所見が不可欠であることを述べる．

　315 patients with advanced gastric cancer have been treated with cytotoxic agents in the past ten years. Gastrectomy was not done in about 70% of them, but in the remaining patients, cytotoxic chemotherapy was carried out for postoperative recurrence or as postoperative adjuvant therapy.

　The age of non-operated patients ranges from 20 to 80, and 32.5% of them were older than 70 years of age. In this group, Borrmann type 2 cancer was seen in 16%, Borrmann type 3 in 38% and Borrmann type 4 in 45%. Performance status in this group was 1 in 12.4%, 2 in 35.6%, 3 in 40.7% and 4 in 11.3%.

　Recently, new criteria at evaluation of chemotherapy for solid tumor were proposed in Japan by the reference to WHO and ECOG's criteria. 151, 112 nonoperated and 39 operated cases, of the 315 cases were evaluable on the criteria. Complete response was achieved in 2 cases and partial response in 11 with the response rate of 11.6% in the 112 non-operated cases. While, in the 39 cases with postoperative recurrence, complete response was encountered in 1 case and partial response in 2 with the response rate of 7.7%. The response rate in both groups was 10.6%.

　Tumor regression rate in these patients was calculated by the X-ray measurement of either palpable tumor or tumor on the views. Tumor regression rate could be calculated on the X-ray views in 109 cases. 62% of whom had palpable tumor. The response rate in the 109 cases was 6.4% with complete response of 3 cases and partial response of 3.

　From the viewpoint of improvement in X-ray and gastroscopic findings, cytotoxic chemotherapy was thought to be effective in 13 cases on our own criteria with the effective rate of 11.9%, and the tumor on the X-ray view disappeared in 3 of them. X-ray and gastroscopic findings altered from those of advanced cancer to those of early cancer in 3 cases, and furthermore, minor improvement on the x-ray and gastroscopic views, judged by several doctors, was also encountered in 7 cases. Improvement on the X-ray and gastroscopic views was not seen in relation to tumor regression, and flattening of the elevative part of cancer focus and shrinkage of the ulcerative part were the sign of improvement.

　In Borrmann type 4 cancer, improvement in pliability or deformity of the stomach seems to be the sign of response to chemotherapy, and therefore, Borrmann type 4 cancer is not evaluable on the new criteria.

　50% survival period in the 13 patients was 46 weeks, and that in the patients with complete or partial response on the new criteria was 32 Weeks.

　In view of the clinical effect of cytotoxic chemotherapy for gastric cancer, the criteria should be made on the basis of improvement in various x-ray and gastroscopic findings.