Adequacy of nodal harvest in colorectal cancer: a consecutive cohort study.

The presence of nodal metastasis is a critical component of staging in colorectal cancer. Accurate assessment of nodal status requires sufficient node sampling, although the number of such nodes is controversial, with recommendations ranging from 6 to 17 nodes. The purpose of this study was to describe the nodal harvest in colorectal cancer and to identify factors associated with adequate lymph node harvest. Pathology reports from consecutive patients with newly diagnosed colorectal cancer undergoing resection between January 1997 and December 2000 at a tertiary care academic institution were reviewed. Identification of 12 or more lymph nodes was considered to be an adequate nodal harvest based on the current American Joint Committee on Cancer recommendations. Among the 579 consecutive specimens, the number of nodes identified was not stated for 10 (1.7%). Of the remaining 569 specimens, 4700 nodes were identified with a mean of 8.3 nodes per patient (median 7, range 0 to 60). Nodal metastases were identified in 219 patients (38.5%). Patients with one or more positive nodes had greater nodal harvest than those with negative nodes (9.5 vs. 8.2, respectively; P = 0.03). Only 22.4% of patients were found to have an adequate nodal harvest (> or =12 nodes). Right-sided resections, high surgeon volume, and gross examination of specimens by a staff pathologist were associated with higher nodal harvests, compared to left-sided resections, low surgeon volume, and gross examination of specimens by a pathology resident/technologist, respectively. There was no association with pathologist volume. In this study, nodal harvest in patients undergoing resection for colorectal cancer was highly variable. This problem appears to be multifactorial, and is related to patient, pathologic, and surgical factors.