Purpose: How wide excision of the regional mesenteric lymphatic drainage influences survival and recurrence rates following curative resection of colorectal cancers needs to be more clearly defined.
Methods: A series of 2,409 consecutive patients undergoing curative resections with detailed descriptions of the operative procedure and the lymphatic drainage in the surgical specimens provided a unique database to provide meaningful comparisons between high and intermediate level ligation.
Results: High ligation made a statistically significant difference in the death rate from recurrent cancer in patients with Dukes B, AC, and C1 cancers. Based on cancer-related deaths, the probability of five-year survival rate increased with high ligation from 73.9 to 84 percent in patients with Dukes B colon cancers and from 49.0 to 58.6 percent in patients with Dukes C1 colon cancers. In patients with Dukes AC cancers, high ligation increased the five-year survival rate from 64.9 to 80.4 percent. In patients with Dukes C cancers with involved middle level lymph nodes, the five-year survival rate increased from 20.5 to 33 percent and the death rate from recurrent cancer fell from 77 to 59 percent with high ligation. In patients with Dukes AC cancers with four or less involved nodes, the five-year survival rate was increased by high ligation from 50 to 78.6 percent in the colon and from 40 to 71.4 percent in the rectum. When more than four lymph nodes were involved, the survival rate was unaffected by the level of ligation. Although high ligation reduced distant recurrences, its greatest effect was observed in the incidence of local and suture line recurrence. The five-year local recurrence rate in patients with Dukes B who were managed by high ligation was 11.4 percent compared with 18.7 percent with intermediate ligation. In patients with Dukes C cancer, the local recurrence rate was 20.8 percent five years following high ligation compared with 30.7 percent for intermediate ligation. In patients with Dukes B cancer who were undergoing curative resections, the incidence of suture line recurrence was 3.9 percent following high ligation compared with 5.5 percent following intermediate ligation. In patients with Dukes C cancer, the incidence of suture line recurrence was 6.9 percent with high ligation and 11.4 percent with intermediate ligation.
Conclusion: In certain stages of colorectal cancer, the more extensive resection of mesenteric lymphatic drainage associated with high ligation appears to increase the survival rate and reduce the recurrence rate following curative resections.