Role of Lateral Lymph Node Dissection in Rectal Cancer Treatment
Since the flow of lymph vessels from the rectum moves in part into the lateral area of the pelvis, dissection of the lateral lymph nodes has been carried out in selected patients with rectal cancer. In this study, 478 patients (Dukes A: 157, B: 147, C: 174) who were treated during the last 22 years (January 1974 to December 1995) were reviewed. These cases were classified as to two sites of cancer, the upper and middle rectum (Rs + Ra) and the lower rectum (Rb), and as to whether the lateral lymph nodes were dissected (LDG) or not (non-LDG). The dissection rates of LDG for Rb showed a higher ratio in Dukes B (61.1%) and C (62.7%) than in A (33.7%) and those for Rs+Ra. The pathological findings of 170 cases of LDG revealed 12 cases (7.1%) with lymph node involvement. Although there were no significant differences, the one-, three-, and five-year survival rates for patients with LDG were better in Rs+Ra (100.0%, 86.1%, 86.1%) and Rb (96.9%, 90.3%, 82.3%) for Dukes B than those with non-LDG (Rs + Ra: 92.2%, 78.6%, 70.4% and Rb: 95.2%, 70.4%, 65.3%). Therefore, the lateral lymph nodes should be dissected prophylactically in selected cases such as Dukes B and C rectal cancer to prolong survival periods.