[Lymphadenectomy in the treatment of colon cancer]

Lymph node metastasis carries enormous prognostic weight in the evaluation of colon cancer and raises the question of how extensive a lymph node dissection should be. Lymph node dissection has several goals: 1) staging of the cancer at the time of intervention; 2) improving the chances for complete resection and cure; 3) evaluating the thoroughness and quality of a particular surgical procedure. The prognostic value of lymphadenectomy is evident from the direct practical decisions it entails: evidence-based recommendations (Level A) have proposed adjuvant chemotherapy for all patients with Stage III colon cancer since 1990. Studies have shown a statistically significant correlation between the number of nodes examined in an operative specimen and long-term survival in patients with Stage II disease. The more closely lymph nodes are examined, the more metastasis is found; one can then see the aberrations of stage migration described as the "Will Rogers Phenomenon." Without randomized studies, it is impossible to say whether resection of a larger number of lymph nodes actually improves the prognosis or whether that number is simply a marker of better surgical management including the quality of the surgical gesture, the careful pathologic examination of the specimen, and subsequent choices for adjuvant chemotherapy. The recovery of 12 lymph nodes correlates with a better global prognosis. At the very least, it is an effective marker for the quality of the surgical resection and can be used in the evaluation of professional practice.