Colon and Rectal Cancers - Medications

Side effects vary specifically with different drugs, but, in general, they include the following:

Nausea and vomiting. Drugs are available to significantly reduce these dreaded side effects. Serotonin antagonists, especially ondansetron (Zofran), can relieve these side effects in nearly all patients given moderate drugs and most patients who take more powerful drugs. In one study, a combination of dexamethasone (a corticosteroid) with ondansetron taken within 24 hours of chemotherapy achieved either a major or complete reduction in nausea and vomiting.
Diarrhea (very common with 5-FU).
Temporary hair loss (usually minimal with 5-FU).
Weight loss.
Mouth ulcers.
Pain and redness of the hands and feet.
Fatigue.
Anemia.
Depression.

These side effects are nearly always temporary, and medications are available to help manage them. Most patients are able to continue with normal activities for all but perhaps one or two days a month.

More serious complications can also occur and may vary depending on the specific agents used. They include the following:

Increased chance for infection (from suppression of the immune system).
Bleeding.

Targeted Therapies and Biologics

One of the most promising recent developments in cancer treatment research has been the emergence of so-called "targeted therapies". Traditional chemotherapeutic agents can be effective, but because they do not distinguish between healthy and cancerous cells their generalized toxicity can cause severe side effects. Targeted therapies work on a molecular level by blocking specific mechanisms associated with cancer cell growth and division. Because they selectively target cancerous cells, they may induce less severe side effects. In addition, these drugs hold the promise of creating options for more individualized cancer treatment based on a patient's genotype. In the future, diagnostic tests may help doctors identify which patients are more likely to respond successfully to specific drugs.

Biologic therapies use the body's immune system to attack the cancer (immunotherapy). These drugs are derived from biological sources and include vaccines, monoclonal antibodies (MAbs), and gene therapies. Many targeted therapies are classified as biologics.

Targeted therapies involve many different types of drugs and molecular pathways. These include:

Angiogenesis Inhibitors. Anti-angiogenesis drugs inhibit the formation of new blood vessels that supply tumors with the blood, oxygen, and nutrients vital to tumor growth. Angiogenesis inhibitors, such as the monoclonal antibody bevacizumab (Avastin), target vascular endothelial growth factor (VEGF).