Therapy for early-stage colorectal cancer.
Surgery is the only curative option for patients with colorectal cancer. The goal of other modalities, such as chemotherapy, immunotherapy, and radiotherapy, is to prolong survival and reduce the risk of recurrence. Adjuvant treatment is mandatory for patients with stage III colon cancer. At present, 6 months of fluorouracil (5-FU) plus leucovorin (folinic acid) can be considered standard therapy. The data on stage II colon cancer are less convincing, and perhaps only subgroups benefit from adjuvant therapy. Patients with stage II disease should be encouraged to participate in randomized trials. Outside of such trials, one can consider prognostic factors in the decision to offer adjuvant therapy. Patients with T3 or N1-3 M0 rectal cancer should receive combined-modality therapy, i.e., 5-FU-based chemotherapy and irradiation. Until ongoing trials answer the question of whether a patient should be irradiated preoperatively or postoperatively, the type of surgery determines the timing of irradiation. If the tumor is amenable to a sphincter-preserving operation, surgery can be followed by radiation therapy. In patients with fixed tumors and those in whom resectability is an issue, prolonged preoperative radiotherapy is more appropriate. Ongoing trials should optimize existing adjuvant therapy (by achieving an ideal balance between toxicity and effectiveness) and integrate the advantages of recently approved drugs.