OUTCOME OF LOCAL EXCISION FOR LOCALLY INVASIVE RECTAL CARCINOMAS WITHSPECIAL REFERENCE TO HISTOLOGICAL FEATURES AT THE INVASIVE MARGIN

Background: Several researchers reported promising results that local excision with or without postoperative chemo-radiation therapy is an a lternative approach for sphincter preservation in patients with locall y invasive rectal carcinomas. However, indications and long-term resul ts have not yet been determined.Methods: Demographic and pathological characteristics of eight patients with locally invasive tumors undergo ing initially local excision were reviewed with reference to histologi cal features at the invasive margin. Results: All the tumors were well differentiated adenocarcinomas. In all but two tumors, the invasion w as limited within the proper muscle layer. Radiation therapy was given preoperatively in one patient and postoperatively in two patients. Ad ditional bowel resection was not attempted in these three cases. Among the remaining five patients, two received additional bowel resection with lymph node dissection. No lymph node metastasis was observed in t hese two patients. During the average follow-up period of 55 months, t hree patients had regional lymph node metastases at 7, 36 and 72 month s, respectively. Another patient had regional lymph node and distant m etastases at 5 months. Three out of five patients with moderate to sev ere grade of dedifferentiated histology at the invasive margin (H-inv) had regional lymph node metastases. On the other hand, one out of thr ee patients with mild H-inv had lymph node metastases. Conclusions: H- inv may be useful as a clinical predictor of lymph node metastasis. Ho wever, more experience is needed to confirm the usefulness of H-inv in selecting invasive rectal cancer patients in whom local excision is s afe and appropriate.