[Background] Laparoscopic colorectal cancer surgery came to be performed widely, but the oncological validity of this surgery has not been well analyzed. Especially for pathological T1 (pT1) colorectal cancer, the level of lymph nodes (LN) dissection is not clear. [Patients and Method] The study group consists of 321 patients who underwent laparoscopic colorectal resection since April 2000 to September 2006 in our institution. In this series, there were 128 patients (39.9%) of which depth were pT1. In these patients, we collected the data such as patientsf characteristics, tumor location, pathological staging, short-term operative result and recurrence rate retrospectively from hospital medical records to evaluate the appropriate level of LN dissection for pT1 colorectal cancer. Histological findings are based on UICC classification. [Result] All patients who underwent laparoscopic colorectal cancer surgery received D2 or D3 LN dissection. Among these 128 patients with pT1 colorectal cancer, no postoperative mortality was observed and a postoperative morbidity was 3.9%. The mean age is 64.0 year-old, and male: female ratio is 74F54. Forty-one tumors were existed in right side colon, while 87 in left side colon or in rectum. Thirty-four patients (26.6%) were undergone Endoscopic Mucosal Resection (EMR) prior to surgery. Lymph node metastasis was observed in 17 patients (13.3%). In these 17 patients, 13 cases (76.4%) represented well or moderate differentiated adenocarcinoma, and three cases (17.6%) had EMR before surgery. 14 patients represented pN1, and three patients were pN2. However, these metastatic lymph nodes were all detected in a peripheral region, but not in the intermediate region. Cancer recurred in 2 patients (1.6%) of all, and one patient (0.8%) died of multiple lung metastases. [Conclusion] Although further evaluation will be required, D2 dissection of the regional lymph nodes is considered to be reasonable for the treatment of pT1 colorectal cancer.
Program Number: P113