The National Cancer Institute reports that prior to the year 2000, 5-fluorouracil was the only drug available for use in adjuvant chemotherapy for patients with colon cancer that had spread to the lymph nodes, called stage III colon cancer. (See References 1) Since 2000 the number of chemotherapy drugs for stage III and stage IV or metastatic colon cancer has greatly increased. Guided by the results of colon cancer clinical trials, doctors have formulated a series of multidrug adjuvant chemotherapy regimens that improve response rates and overall survival of patients with advanced colon cancer.
FOLFOX Regimen
Patients with stage III and stage IV colon cancer frequently receive the FOLFOX regimen as adjuvant chemotherapy. This consists of 5-fluorouracil, leucovorin, and oxaliplatin, according to the American Cancer Society. (See References 2) Leucovorin, also called folinic acid, is a vitamin that increases the effectiveness of 5-fluorouracil. At the start of therapy, patients get intravenous anti-nausea drugs. Then leucovorin and oxaliplatin are given together as an intravenous infusion over about two hours, explains Macmillan Cancer Support. (See References 3) After this, the patient gets 5-fluorouracil in different ways depending on the particular FOLFOX schedule the doctor has chosen for the patient. In one schedule, FOLFOX6, the patient gets 5-fluorouracil first as an injection and then as an infusion over 46 hours. The patient then has a rest period for 11 days during which there is no administration of chemotherapy drugs. This completes the first cycle of treatment, and patients may get up to 12 cycles depending on their condition.
Capecitabine
According to the National Guideline Clearinghouse, an initiative of the U.S. Department of Health and Human Services, stage III colon cancer patients who have neurologic conditions, those who are at increased risk of neuropathy or those who may be unable to tolerate chemotherapy-related infections should not be considered for oxaliplatin-containing combination therapies such as FOLFOX. (See References 4) Instead, these patients should receive a six-month regimen of capecitabine, an oral chemotherapy medication that is a prodrug of 5-fluorouracil.
FOLFIRI Regimen
The National Cancer Institute explains that the FOLFIRI chemotherapy regimen consists of the drugs 5-fluorouracil, leucovorin, and irinotecan. (See References 5) This is a first-line multiagent treatment for patients who have metastatic or stage IV colon cancer that provides improved response rates relative to the treatment that uses only 5-fluorouracil and leucovorin. On the first day of the FOLFIRI regimen, patients get irinotecan and leucovorin as intravenous infusions over two hours. Following these infusions, 5-fluorouracil is given first as an intravenous injection and then as an infusion from an ambulatory pump over 46 hours. The treatment is repeated every two weeks.
References
- National Cancer Institute: Colon Cancer Treatment
- American Cancer Society: Treatment by Stage of Colon Cancer
- Macmillan Cancer Support: Oxaliplatin and 5-FU Chemotherapy
- National Guideline Clearinghouse: Adjuvant Systemic Chemotherapy for Stage II and Stage III Colon Cancer
- National Cancer Institute: Colon Cancer Treatment: Stage IV and Recurrent Colon Cancer
