Predictive factors for lymph node yield and metastases in colorectal carcinoma

Abstract

Aims To assess predictive factors for lymph node yield and metastases in resections for colorectal carcinoma at a single, tertiary level hospital. To determine the lymph node size most predictive of nodal metastases. Methods Consecutive cases between 2008 and 2010 were identified from our database. Clinical and pathological data were obtained from medical records and pathology reports. The size of nodes recovered and any metastases were measured from paraffin sections. Age, sex, surgery type, tumour site, size, grade, neoadjuvant treatment and lymphovascular invasion were entered into a multivariate regression model to determine independent predictors of nodal yield and metastases. Nodal size most predictive of metastases was determined using receiver operating characteristic curves. Results 94 cases were analysed including 1398 lymph nodes. Median number of nodes recovered was 14 (range 2-35). Mean number of positive nodes was 1 (±2.8). Tumour size independently predicted for increased nodal yield (p = 0.04). Neoadjuvant treatment reduced the nodal yield (p = 0.03). The most predictive factors for metastases were tumour grade (p Conclusion A reduced lymph node yield should reasonably be expected in patients treated with neoadjuvant therapy. A nodal size of 5.4 mm in the long axis represents the best compromise between sensitivity and specificity for detection of metastases.