Colorectal cancer will be diagnosed in approximately 150,000 patients in the USA this year.
Chemotherapy has recently been shown to improve survival when given as adjuvant
therapy to surgery in patients with stage III
colorectal cancer. Demonstration of this benefit required large, randomized controlled trials. Either
5-fluorouracil (5-FU) and
leucovorin for 6 months or
5-FU and
levamisole for 12 months are currently considered standard adjuvant treatment for stage III
colorectal cancer. However, current adjuvant trials are comparing continuous infusion and intravenous bolus
5-FU regimens and oral
uracil/
Ftorafur with intravenous
5-FU and
leucovorin, as well as studying the timing of
chemotherapy in the adjuvant setting. Subsequent adjuvant trials will examine newer regimens with activity in advanced
colorectal cancer, as well as the efficacy of
monoclonal antibodies. Other trials will study which type of surgery is optimal and whether adjuvant
therapy is helpful in stage II
colon cancer. Trials in metastatic disease will focus on combinations of newer agents which may improve survival in this patient group. Studies in
rectal cancer will focus on determining which agents are optimal in combination with
radiation therapy in the adjuvant setting. Molecular characteristics of
tumor cells are being defined, which may guide
therapy in the future. Careful, logically designed clinical trials will hopefully provide more efficacious
therapy for this common
cancer.