RESUMEN
Introduction: the correct evaluation of lymph node disease influences the therapeutical decisions of colon and rectal cancer(CRC) patients. The number of dissected lymph nodes is a variable that have prognostic value and serves as an indicator of thequality of oncology treatment. For a correct evaluation of N stage to be accepted, the minimum number of dissected lymphnodes considered must be 12. In rectal cancer patients submitted to neoadjuvant radiochemotherapy, the interpretation of thenumber of dissected lymph nodes remains inconclusive. Objective: is to evaluate the number of dissected lymph nodes in CRCpatients submitted to curative surgery and determine this latter impact in oncologic treatment results. In cases of rectalcancer, to study the effect of neoadjuvant radiochemotherapy in dissected lymph nodes count. Method: in the period 1991-2004, 852 CRC patients were treated in Hospital A. C. Camargo . Patients with metastases at the time of diagnosis,synchronous and metachronic tumors, total colectomy or total proctocolectomy and hereditary colorectal cancer were excluded.The sample was constituted by 423 patients with sporadic colorectal adenocarcinoma who undergone curative radical surgery(168 colon primary tumors and 255 rectal tumors). Colon cancer patients, treated primarily by surgery, had also receivedadjuvant chemotherapy (5-FU) according to risk criteria. Rectal cancer patients with fixed or half-fixed injuries or clinicallycompromised lymph nodes (T3, T4 or N+) had received neoadjuvant radiochemotherapy, followed by surgery and chemotherapy(5-FU). Results: the median of the number of dissected lymph nodes in colon cancer patients was 17. In the case of rectalcancer patients, the median of dissected lymph nodes in the groups with and without neoadjuvant radiochemotherapy had beenrespectively 9 and 15 (p<0.001). 5-year specific survival rates for colon and rectal cancer patients were respectively...