IN VIVO SENTINEL NODE PROCEDURE IN RESECTABLE COLON CANCER

ABSTRACT (English) Introduction Colorectal cancer is a significant cause of morbidity and mortality. Lymph node involvement is the most important predictor of prognosis, decreasing the five-year survival rate to only 45-50%. Recurrence after curative resection is substantial, possibly due to incomplete harvest or inaccurate pathological assessement. The sentinel node can facilitate time consuming and expensive pathological examination by identifying single lymph nodes that harbor the greatest potential of metastases. This may lead to a better selection of high-risk patients who could benefit from additional neoadjuvant treatment. Aim The primary objective is to determine the feasibility and safety of the in vivo sentinel node procedure in colon carcinoma, during open and minimal invasive surgery. Secondary, increasing the lymph node yield by using blue dye and a X-ray of the specimen. Methods A prospective single centre pilot consisting of 30 patients with colon carcinoma undergoing a hemicolectomy with sentinel lymph node-procedure during open surgery or minimal invasive surgery and a retrospective control group treated in the conventional way. In the SN-group 1 cc of patent blue is injected subserosally near the tumor and the SNs are identified and marked. All lymph nodes undergo standard H&E-staining. The SNs are ultrastaged with IHC and RT-PCR. The X-ray is used as an aid for finding the non-sentinel lymph nodes. Results The first uncomplicated procedure was performed during a rightsided open hemicolectomy. Multiple blue nodes were identified and the first four marked as SNs. Total n of analyzed lymph nodes= 15, vs. control group = 12.7. Conclusion Preliminary results are encouraging. No essential technical problems or safety issues became evident. Protocollising the sentinel lymph node (SLN) procedure in colon carcinoma and additional studies on the implications of micrometastases, discovered with different IHC-markers, and the benefits of neo-adjuvant chemotherapy in these cases are essential.