Prevention of local recurrence by extended lymphadenectomy for rectal cancer.

This study was undertaken to determine if the degree of lymphadenectomy correlates with the prevention of local recurrence. The authors retrospectively reviewed the clinical data of 269 patients who underwent curative surgery for rectal cancer. The study was divided into three periods based on the method of lymphadenectomy as follows: period I (1963-1979) when extended lymphadenectomy was not performed; period II (1980-1985) when this was partially done with no attempt to dissect the obturator and proximal middle rectal lymph nodes; and period III (1986-1990) when this was completely performed for patients with appropriate indications. The local recurrence rates were 21%, 10%, and 8% for Periods I, II, and III, respectively (P < 0.05). The incidence of local recurrence tended to be greater in period I versus periods II and III according to type of operation, location, and stage of the primary tumors. The local recurrence rates arising from lateral node metastases were 11%, 4%, and 2% for periods I, II, and III, respectively (P < 0.05), while the incidence related to an insufficient surgical margin was approximately 5% throughout the three periods. We thus conclude that the degree of lymphadenectomy is a major determinant of local recurrence following a curative operation for rectal cancer.