The sentinel node procedure in colon carcinoma: A multi-centre study in The Netherlands

Background: Lymph node status is the most important predictive factor in colorectal carcinoma. Recurrences occur in 20% of the patients without lymph node metastases. The sentinel lymph node (SLN) biopsy is a tool to facilitate identification of micrometastatic disease and aberrant lymphatic drainage. We studied the feasibility of in vivo SLN detection in a multi-centre setting and evaluated nodal micro-staging using immunohistochemistry (IHC). Materials and methods: Sub-serosal injection with Patent Blue dye was used in the SLN procedure in 69 patients operated for localized colon cancer in six Dutch hospitals. Each SLN was examined with routine haematoxylin-eosin staining. In tumour-negative SLNs, we performed CK7/8 or 18 IHC. Results: The procedure was successful in 67 of 69 patients (97%). The SLN was negative in 43 patients. In three cases, it was false negative, resulting in a negative predictive value of 93% and an accuracy of 96%. In 24 of 27 patients with lymph node metastases in a successful SLN procedure, the SLN was positive (sensitivity 89%). In 15 patients, the SLN was the only positive node (21%). In nine patients, we only found micrometastases or isolated tumour cells, resulting in 18% upstaging. Aberrant lymphatic drainage was seen in three patients (4%). Conclusion: The SLN procedure in localized colon carcinoma is reliable in a multi-centre setting. It is helpful to identify patients who would be classified as stage II with conventional staging (18%) and who might benefit from adjuvant treatment.