The role of sentinel lymph node analysis in patients with colorectal cancer undergoing surgery

Aim: our aim was to identify and analyse sentinel lymph nodes in patients undergoing curative surgery for colorectal cancer, using two distinct methods, in vivo and ex vivo. Material and methods: we conducted a prospective study consisting of a total of 22 patients diagnosed with stage I-III colorectal cancer, hospitalized and undergoing radical surgery. Two different techniques were employed to identify sentinel lymph nodes, in vivo and ex vivo, using 1% methylene blue vital stain. Sentinel lymph nodes and resections were examined morphopathologically using the standard method. N0 was the case of patients with negative sentinel lymph nodes or other types of lymph nodes, performed together with immunohistochemistry in order to identify micrometastasis for both sentinel lymph nodes and other lymph node biopsies. Resuts: Mean age in the study group was 70 years, patients aged between 59 and 84 years. Of these, 12 (54.5%) were men and 10 (45.5%) were women. In terms of topography, the tumor was localized in the cecum in 3 (13.6%) cases, in the ascending colon in 3 patients (13.6%), in the transverse colon in 3 (13.6%) cases, in the left colic flexure in one case, in the descending colon in one case, in the sigmoid colon in 8 (36.6%) patients and in the rectum in 3 (13.6%) patients. The ex vivo technique was characterized by 88.8% accuracy, 83.3% sensitivity and a false negative rate of 16.7%. The in vivo technique was characterized by 75% accuracy, 75% sensitivity and a false negative rate of 25%. Conclusion: The two techniques, ex vivo and in vivo, cand be used with comparables results.