Adjuvant therapy in colon cancer

Huge advances have been made in the treatment of colon cancer over the last decade. Success has been most noticeable in stage IV disease - where careful selection of patients with small-volume disease for treatment with surgical resection +/- perioperative chemotherapy has resulted in an improvement in survival of approximately 5-50%; and stage III - disease where the advent of 5-fluorouracil/oxaliplatin, as adjuvant treatment has also resulted in a significant prolongation in survival. Progression-free survival is now an established surrogate for overall survival, and has resulted in more timely reporting of adjuvant studies and therefore faster integration of promising agents into the clinic. Targeted agents, which have shown promise in the metastatic setting, are currently being examined in the adjuvant setting, although results so far are disappointing. Patients with high-risk stage II cancer remain a challenging group. They have a poorer prognosis than those with stage IIIA disease, and national and international guidance recommend offering chemotherapy after careful discussion of the pros and cons. Despite the fact that we have identified many of the biological features that make stage II disease higher risk, we still struggle to achieve the same improvement in survival for this subgroup compared with others. It may be that these patients required treatment with alternative regimens and predictive biomarkers would be particularly helpful.