SURGICAL TREATMENT OF EARLY RECTAL CANCER

Abstract

Forty-six cases of early carcinoma of the lower rectum were investigated clinico-pathologically in order to study the adequate surgical treatments for the disease.
There were 22 “m” cancers invaded the mucosal layer. Local excision was performed in 10 cases of them. No venous invasion and lymphatic vessel invasion were shown in these 10 cases. Bowel resection with lymph node dissection was performed in 12 cases of 22 “m” cancers. Neither venous and lymphatic vessel invasion nor lymph node metastasis were shown in these 12 cases with lymph node dissection. Moreover, there was no complication after the operation in local excision cases. Therefore, local excision would be enough procedure for “m” cancers.
In contrast, there were 24 “sm” cancers invaded submucosal layer. Local excision was performed in six cases of them and bowel resection with lymph node dissection was done in 18 cases. Lymphatic vessel invasion was shown in ten (41.7%) of 24 “sm” cancers, and lymph node metastasis in five (27.8%) of 18 cases with lymph node dissection. Local recurrence on the lower rectum was experienced in one (16.7%) of six cases of local excision. The levels of sm invasion of those cases were all sm2 or sm3 according to Kato's classification. Therefore, in “sm” cases, especially those invaded the deep submucosal layer, lymph node dissection should be performed.
The correct diagnosis of the depth of invasion is one of the most important factors in selecting the appropriate treatment. Endoscopic ultrasonography was useful to diagnose the depth of invasion of cancer preoperatively.