Colon and Rectal Cancers - Medications

Chemotherapy for Stage III Patients with Colon Cancer. Since the early 1990s, adjuvant chemotherapy with 5-FU and leucovorin has been the standard of care for stage III colon cancer. Numerous trials have shown that adjuvant chemotherapy in this setting reduces the absolute risk of death from colon cancer by approximately one-third and improves survival by 10%. Current clinical trials are investigating whether the addition of new chemotherapy drugs, suchas irinotecan, oxaliplatin, capecitabine, and antibody therapies, will improve cure rates over 5-FU and leucovorin alone. However, most of these new agents should currently not be used for adjuvant treatment of colon cancer unless as part of a clinical trial.

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Chemotherapy for Advanced Colorectal Cancer. Chemotherapy and radiation are generally used to reduce symptoms and prolong life in advanced colorectal cancer. Some experts suggest that chemotherapy should be considered for the following patients:

Able to carry out all normal activity without restriction.
Restricted in physically strenuous activity, but able to walk about and carry out light work.
Able to walk about and capable of all self care, but unable to carry out any work. Out of bed or chair for more than 50% of waking hours.

Chemotherapy in most studies offers a modest improvement in survival and often relieves symptoms. One 2003 study suggested that for these patients chemotherapy given intermittently has fewer toxic or serious adverse effects and may be as beneficial as continuous administration.

The following patients are unlikely to benefit from chemotherapy:

Those capable only of limited self care. Confined to bed or chair for more than 50% of waking hours.
Severely disabled. Cannot carry out any self care. Totally confined to bed or chair.

Specific Chemotherapy Agents

5-Fluorouracil (5-FU) with Leucovorin. Adjuvant therapy using 5-fluorouracil along with leucovorin (5-FU/LV) is currently the standard treatment for patients with high-risk colon cancer (Stage III or selected patients with Stage II tumors). Leucovorin, also called folinic acid, is a form of the B vitamin folic acid. Patients are given a series of cycles that usually continue for at least six months. 5-FU is given intravenously at present, but oral preparations are currently being tested in clinical trials.

There are many different ways of giving 5-FU, including intravenously over several hours once a week, intravenously daily for five consecutive days every month, or as continuous infusion with a portable pump.