Adequacy of Nodal Harvest in Colorectal Cancer: A Population Based Study
Abstracts
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BACKGROUND: The presence of nodal metastasis is a critical component of staging in colorectal cancer and often determines the use of adjuvent therapy. Accurate assessment of nodal status requires sufficient node sampling, although the number of such nodes is controversial, with recommendations ranging from 8 to 17. Using a population-based approach, the purpose of this study was to describe nodal harvest in colorectal cancer, and to identify factors associated with suboptimal nodal retrieval. METHODS: The pathology reports of 409 consecutive patients with newly diagnosed colorectal cancer undergoing resection from 01/97-12/99 at a tertiary care academic institution were reviewed. Demographic, tumor, surgery and pathology-related factors were analyzed. The identification of at least 8 lymph nodes was considered to be an adequate nodal harvest based on the minimum acceptable standard from published evidence. RESULTS: Among the 409 consecutive patients, the number of nodes identified was not stated for 19 patients (4%). Of the remaining 390, patients 3052 nodes were identified with a mean of 7.83 nodes/ patient (range 0-31, median 7). No nodes were identified in 5 (1%) patients and only 1-3 nodes were identified in 75 (18%) patients. One or more positive lymph nodes were identified in 147 patients (38%). Patients with positive nodes had greater nodal harvest than those with negative nodes (8.5 vs. 7.4, p=.03). Only 177 (43%) patients were found to have adequate nodal harvest (8 or more nodes). On multivariate analysis, surgeon volume (p=0.03), pathologist volume (p=0.03) and type of resection (p=.004) were significantly associated with adequate nodal harvest. CONCLUSIONS: In a population-based study, nodal harvest in colorectal cancer was highly variable. Despite published guidelines, the majority of patients did not undergo adequate nodal harvest using the most conservative recommendations. This problem appears to be multifactorial, related to both surgical and pathologic factors. |