[Sentinel lymph node detection in colorectal cancer: importance, techniques and results]

Considering that lymph node status is a key factor in colorectal cancer staging, and the main determinant for adjuvant therapy of colorectal cancer being this therapy, responsible for a significant increase in colorectal cancer patients survival, the staging methods should be the most accurate possible in order to offer this individuals the opportunity to be adequate treated in order to achieve the best survival possible. Sentinel lymph node study is progressively being popularized as a method that increases sensibility in detect positive nodes to reveal a more accurate stage and prognosis in colorectal cancer patients.

Thirty one colorectal cancer patients were prospectively studied and sentinel lymph node was identified in 100% of the cases utilizing either patent blue alone, or in association with radiotracer based on technetium 99m colloid solution in a randomized fashion.

The mean number of sentinel nodes per patient was 1.96 ranging from 1 to 3 nodes. With the addition of transoperative lympho-scintigraphy five extra sentinel nodes, not identified by the blue dye alone, were identified and considered for histopathology study. In four cases (12.9%) the sentinel lymph node was the only site of metastasis, all of them being detected by association of hematoxylin and eosin and immunohistochemical examination.

Sentinel lymph node detection and analysis is feasible, technique is relatively simple and is able to produce upstage in colorectal cancer. Blue staining and radio guided techniques are both safe and their superposition has shown good results in terms of increase accuracy in our experience. There was no aberrant lymph drainage that would alter resection margins in patients studied. Upstaging rate, identifying potential candidates for adjuvant therapy was 12.9% (4/31). To this individuals chemotherapy could be a chance to increase their global survival.