Cáncer de colon y recto: Conceptos actuales en la patonegia, diagnóstico precoz, estudio de extención, prnóstico y tratamiento

Colorectal cancer is, after lung cancer, the second cause of death due to cancer in the western world. A better understanding of molecular mechanisms of pathogenesis may induce a series of changes in early diagnosis, prognostic assessment and therapy. Screening programs for early diagnosis, prognostic assessment and therapy. Screening programs for early diagnosis may help in reducing mortality by detecting adenomas or non-invasive tumors amenable to curative surgery. Prognostic is largely based upon anatomic criteria defined by Dukes classification and better expressed by the TNM staging system. For stage III patients, adjuvant chemotherapy is well known to improve survival. Such a benefit may also extend to some stage II patients with poor prognostic variables. Total mesorectal excision has become the standard surgical technique for rectal cancer patients, reducing the risk of local relapses. Moreover, rectal ultrasonography and resonance magnetic imaging make possible preouperative staging of rectal cancer patients. In those with locally advanced tumors, preoperative chemoradiation may improve results. In patients with advanced disease treatment is basically palliative. However, new combinations of drugs based on 5FU plus irinotecan or oxaliplatin are able to extend median survival. Surgical resection of limited liver or lung metastases is also of critical importance.