Prediction of the Adequacy of Lymph Node Retrieval in Colon Cancer by Hospital Type

Background: Examination of 12 or more regional lymph nodes (LNs) is the accepted minimum for nodal staging in colon cancer and serves as a surrogate for adequate resection. Objective: To determine the contributing role of the hospital in the number of LNs retrieved. Design/Setting: We retrospectively reviewed colon resections in 83 patients by 2 surgical oncologists at a National Comprehensive Cancer Network (NCCN) hospital or at community-based hospitals from January 1, 2002, through December 31, 2007. Patients: We included all patients undergoing colectomy for primary colon cancer and excluded patients with recurrence, rectal cancer, or preoperative chemotherapy. Main Outcome Measures: Total number of LNs retrieved. We also analyzed clinical factors accounting for differences. Results: The median number of LNs examined at the NCCN hospital (42 patients) vs the community hospitals (41 patients) were 17.8 vs 7.0 (P<.001), and the frequency of an inadequate number of LNs examined (<12) was 11 of 42 cases (26%) vs 35 of 41 cases (85%) (P<.001). Potential predictive factors for LNs retrieved were grouped into modifiable (hospital type, surgeon, and surgical approach [laparoscopic vs open]) and nonmodifiable (age, sex, and tumor location). On multivariate analysis of the factors, hospital type was the only modifiable factor predictive of LNs reported (P<.001). Conclusions: Our study is the first, to our knowledge, to demonstrate that the number of LNs removed in colectomies performed by the same 2 surgeons depends on the hospital type (NCCN vs community) in which the resection occurred. We postulate that the number of LNs retrieved may be related to the institution's pathological review in addition to the extent of surgical resection.