Sentinel Lymph Node in Colorectal Carcinoma

Abstract

Background: Metastasis to the regional lymph nodes is an important prognostic factor in colorectal cancer and nodal evaluation is essential for accurate staging. Sentinel lymph node (SLN) mapping is an additional method for improving colorectal cancer nodal staging. Objective: To evaluate the identification of SLN sensitivity and accuracy of nodal staging, its upstaging benefits and pattern of nodal metastases in colorectal carcinoma. Patients and Methods: Lymphatic mapping was performed using patent blue in sixty patients with histopathologic diagnosis of colorectal carcinoma. Enhanced pathologic examination was carried out on (SLNs) using Haematoxylin & Eosin and immunohistochemistry. Results: The patients studied had an average tumor size 6.6 cm and rectal tumors represented 43.3% of the group. Colon tumors had SLN identification rate of 94.1%, while rectal tumors had 80.8%. Overall, SLN mapping accuracy was 75.4%, sensitivity 66.7% and 33.3% false negative rate. Upstaging rate was 10.5%. No aberrant lymphatic drainage could be detected in our patients. Conclusion: Intraoperative SLN mapping technique is feasible, safe, accurate, and has no apparent side effects. Implications for long-term survival and prognosis need to be further evaluated in additional studies.