Impact of tumor location on nodal evaluation for colon cancer

PURPOSE: Adequate lymph node evaluation is important to stage colon cancers and make adjuvant treatment decisions. Studies have demonstrated improved survival when >= 12 nodes are examined. Our objective was to assess differences in the adequacy of nodal evaluation for right vs. left colon cancers. METHODS: From the National Cancer Data Base (1998-2004), 142,009 N0M0 colon cancer patients were identified. Logistic regression was used to evaluate the number of nodes examined for right vs. left colectomies. Multivariable modeling was used to determine the impact of examining >= 12 nodes on survival. RESULTS: Of 142,009 patients, 79,444 (56 percent) had right colectomies, and 62,565 (44 percent) patients had left colectomies. More nodes were examined during right colectomies than left (median 12 vs. 8, Pe < 0.0001). When adjusted for patient, tumor, and hospital factors, patients undergoing left colectomy were less likely to have >= 12 nodes identified (P < 0.0001). Patients were more likely to have >= 12 nodes identified for right and left colon cancers at high-volume hospitals. Survival was better with examination of >= 12 nodes for right and left colon cancers (P < 0.0001). CONCLUSIONS: Evaluating >= 12 nodes for right and left colon cancers is a feasible, clinically relevant, and modifiable factor that will likely improve patient outcomes.