大腸sm癌の細分類に基づいた局所的治療法の選択

Management of Patients with Colon and Rectal Polyps Containing Adenocarcinoma Invasive as far as the Submucosa

要旨　自験の大腸sm癌238症例とそのうちのリンパ節転移・再発18例を分析し，大腸sm癌の局所的治療の適応を検討した．脈管侵襲は転移・再発と有意の関連を示し，sm浸潤度，先進部組織型も関連が示唆された．これら3因子による転移・再発率の解析では，脈管侵襲のないsm₁症例，先進部高分化症例には転移・再発例は認めなかった．また，脈管侵襲のないsm₂，sm₃症例の2.5％にのみ転移．再発を認めた．一方，脈管侵襲を伴うsm₂，sm₃症例の転移・再発率は20.6％，脈管侵襲を伴う先進部中分化症例の転移・再発率は21.1％の高率に達した．今回の検討から，sm癌の追加腸切除の基準として癌先進部の病理所見の重要性が強調された．

　Between 1975 and 1993, 238 patients with colon and rectal polyps containing adenocarcinoma invasive as far as the submucosa were treated. Fifteen of 161 patients treated by colonic resection were found to have metastatic lymph nodes and six patients including three of those with metastatic lymph nodes were found to have local recurrence or distant metastasis. Histologically, all specimens were examined to evaluate the risk for metastasis at the time of polypectomy. The findings revealed that depth of invasion, lymphovascular invasion and histologic type of the invasive front correlated well with the risk of metastasis. Consideration of these risk factors indicated that, if there is no lymphovascular invasion, carcinoma invasive as far as sm₁level or with well differentiated adenocarcinoma at the invasive front should be treated by endoscopic polypectomy or local excision. But, it was also shown that, if there was lymphovascular invasion, carcinoma invasive as far as sm₂, sm₃ level or with only moderately differentiated adenocarcinoma at the invasive front had about 20percent risk of metastasis.