Chemotherapy For metastatic colon cancer, 5-fluorouracil (5-FU) can be used as a single agent
(given by rapid injection or continuous infusion) or as part of combination chemotherapy .
For over 25 years, adjuvant chemotherapy trials have tried to improve the surgical cure rate of colon cancer. 5-FU has been combined with other agents such as leucovorin and/or levamisole . Combination therapy is better than 5-FU alone, and recent reports show an increase in survival and a decrease in recurrence .
Trials for Stage II patients (Dukes' B2 and B3) are comparing 5-FU + leucovorin and 5-FU + leucovorin + levamisole, a drug that may work as a "biochemical immune modulator" to make 5-FU more effective at killing cancer cells .
For people with Stage III (Dukes' C) colon cancer with positive lymph nodes who are unable to enter a clinical adjuvant trial, the combination of levamisole or leucovorin and 5-FU has shown a clear benefit, with reduced rates of both recurrence and death.
Reports on using 5-FU and interferon-alpha (chemoimmunotherapy) for metastatic colon cancer (Stage IV) have shown an increased response rate, and new studies are trying to confirm these preliminary reports. This combination program has increased toxicity, however, with such side effects as fatigue, fever, diarrhea and sore mouth.
