Role of Paraaortic Lymph Node Dissection for Cancer of the Rectum and Sigmoid
To clarify whether paraaortic lymph node dissection (distant dissected group, DDG) for cancer of the rectum and sigmoid actually confers any significant 5-year survival advantage on patients over non DDG, the outcome of 761 patients (Dukes A: 215, B: 205, C : 204, D:137) was reviewed. We studied 217 cases with sigmoid (S) cancer (Dukes A : 66, B : 64, C : 41, D : 46), 86 cases with rectosigmoid (Rs) cancer (Dukes A: 17, B: 30, C: 19, D: 20), 228 cases with middle rectal (Ra) cancer (Dukes A : 51, B : 58, C : 80, D : 39), and 230 cases with lower rectal (Rb) cancer (Dukes A : 81, B : 53, C : 64, D : 32). The one-, three-, and five-year survival rates of all these patients were as follows, respectively; Dukes A: 96.2%, 93.9%, and 89.3%, B: 96.0%, 84.6%, and 78.2%, C : 90.1%, 63.0%, and 51.4%, and D : 51.7%, 15.0%, and 7.6%. There were significant differences (p<0.01) in their survival rates between each stage. Between DDG and non DDG, statistical differences were found in S, Rs, and Ra of Dukes B, and also in the rectum (Ra+Rb) of Dukes D. These results revealed that prophylactic distant node dissection for advanced cancer of the rectum and sigmoid and aggressive DDG for Dukes D stage contributed to improvement of the survival rates.
