Effects of extended systematic lymphadenectomy for adenocarcinoma of the rectum--significant improvement of survival rate and decrease of local recurrence.

The effects of extended systematic lymphadenectomy were evaluated by the rate of survival of the patients and incidence of local failure in 643 patients with single primary adenocarcinoma of the rectum, who were operated on at the National Cancer Center Hospital from 1962 to 1981. Our extended systematic lymphadenectomy consists of high ligation of the inferior mesenteric vessels and meticulous dissection of the abdominopelvic lymphatic system. Potentially curative resection was performed on 495 patients (77%) with seven operative deaths (1.4%). Extended systematic lymphadenectomy was carried out on 74 of 168 patients with Dukes B cancer and 89 of 213 patients with Dukes C cancer. Five-year survival rates for patients with or without systematic extended lymphadenectomy were 83.2% vs 63.7% (P less than 0.05) in Dukes B and 52.5% vs 30.8% (P less than 0.05) in Dukes C classes. The cumulative incidence of local failure at 5 years was decreased from 26.1% to 8.4% (P less than 0.01) and from 44.3% to 24.5% (P less than 0.01) by extended lymphadenectomy in Dukes B and C classes, respectively. Prolongation of operation time (plus 60 min), slight increase in blood loss (plus 150 ml) and no increase in operative mortality (1/161, 0.6%), were observed in the case of extended lymphadenectomy.