Chemotherapy Treatments for Colon Cancer: What are the Top 7 Chemotherapy Drugs?
Chemotherapy has been shown to be an effective treatment for many types of cancer, including colon cancer. According to information from the Medline Plus Encyclopedia, “The chemotherapy drug 5-fluorouracil has been shown to increase the chance of a cure in certain patients.” (1)
Rest assured that is your doctor has prescribed chemo, there is good cause. The National Cancer Institute defines chemotherapy as “Chemotherapy (also called chemo) is a type of cancer treatment that uses drugs to destroy cancer cells.” (2) The seven chemotherapy drugs used to fight colon cancer are:
These medications may be used alone or in various combinations with each other.
The chemotherapy drug 5-fluorouracil, or 5-FU, interferes with the cancer cells’ DNA replication. The normal administration route is by intravenous injection. Patients may experience some of these common side effects:
- Decreased red blood cell production (anemia)
- Decreased white blood cell production (neutropenia)
- Decreased platelet production (thrombocytopenia)
- Mouth sores
This drug is used as part of the Saltz regime, and the FOLFOX regime.
Irinotecan - Camptosar
Irinotecan, marketed under the name Camptosar, is injected into the veins slowly through an intravenous drip (IV). It inhibits the growth of the cancer cells by blocking the enzymes they need to divide and multiply. It can be given alone, or in combination with 5-fluorouracil (5-FU) and/ or leucovorin (LV). When it is used in combination with 5-FU and LV, it is referred to as the “Saltz regime.”
It may cause interactions with other medications or herbs such as:
- St. John’s Wort
Irinotecan may cause side effects, which include, but are not limited to, loss of appetite, constipation, hair loss, nausea, vomiting, or diarrhea. It also increases the risk of bleeding or infections in individuals because it may lower the body’s production of white and red blood cells, and platelets. The most common side effect is diarrhea; consult your physician for advice if this occurs.
Individuals that are pregnant or breastfeeding, or who have diabetes or liver disease may not be candidates for irinotecan treatments.
Capecitabine - Xeloda
Capecitabine is a prodrug of 5-FU and an antimetabolite. It is enzymatically converted to 5-FU in the tumor. It interrupts and interferes with cancer cell growth. It is typically administered orally but can be given intravenously. Currently, it is the only pill-type treatment approved for colon cancer. The benefits of this particular drug are patients do not have to submit to an IV, and the treatment can be taken anywhere, thus alleviating the need for a hospital visit.
Some side effects are vomiting, diarrhea, hand-foot syndrome, neutropenia, anemia, or anorexia, with the diarrhea and hand-foot syndrome being the most common and severe side effects. Hand-foot syndrome, also called Palmar-Plantar Erythrodysesthesia, causes redness, tenderness, or peeling of the skin.
Oxaliplatin - Eloxatin
Oxaliplatin is given with 5-FU and leucovorin (LV), in a two-day treatment that is called the FOLFOX regime. The chemotherapy is repeated every 14 days until individuals show a response to the medication. The purpose of the addition of the LV to the treatment is to limit the risk of individuals developing mucotoxicity from the chemotherapy treatment. According to the Moffit Cancer Center, mucotoxicity is “inflammation of the mucuous membrane of the gastrointestinal tract.” (3)
Some drugs that may cause interactions with Oxaliplatin are:
- Polymyxin B
Oxaliplatin may cause side effects such as:
- Nerve system damage resulting in numbness or tingling in the extremeties or jaw tightness
- Neutropenia, where the body produces fewer white blood cells
- Anemia, where the body produces fewer red blood cells
- Thrombocytopenia, where fewer platelets are produced
- Hyper-sensitivity to cold
Individuals with platinum allergies should not use Oxaliplatin. Those who are pregnant or nursing should consult with their physician prior to receiving Oxaliplatin treatments, as should those with asthma, Raynaud’s syndrome, or liver disease.
Monoclonal Antibody Drugs
Genetically engineered biological drugs, which are also called monoclonal antibody drugs, are used either singly or in conjunction with the other drugs previously mentioned. The three approved medications are:
Bevacizumab is administered with irinotecan, 5-fluorouracil, and leucovorin. It cuts off the blood flow to the cancer cells, and prevents new blood vessels from forming.
Cetuximab and panitumumab disable the epidermal growth factor receptor (EGFR) and stop the growth of the cancer cells. Cetuximab may be used singly or in combination with irinotecan, and is given intravenously. There is a serious side effect associated with its use, called, infusion reaction. It may also cause photosensitivity, chills, dizziness, and skin blistering. This is not meant to be a complete list of possible side effects, but rather an overview of some of the common ones.
Is Chemotherapy for Everybody?
While most patients respond well to chemotherapy, there is a population of individuals who do not respond to these treatments for genetic reasons. According to researcher Dr. George Kim, “If you have Stage II colon cancer, ask your doctor about a test for “deficient mismatch repair proteins.” If you have MMR, your cancer may not respond to some chemotherapy treatments, however, a study done at the Mayo Clinic shows patients may benefit from treatments with 5-FU and leucovorin. (4)
This brief overview of the chemotherapy treatments for colon cancer provides good general information, but those suffering from colorectal cancer should consult their physician for specific advice and treatment recommendations for their condition. Please read this disclaimer about the information you just read.
1. Medline Plus Encyclopedia, updated 11/05/2009
2. National Cancer Institute, “Chemotherapy and You: Support for People With Cancer,” 06/29/2007
3. Moffit Cancer Center, H. Lee Moffitt Cancer Center & Research Institute, Rod Quilitz, PharmD,
4. Lammers, Carol, Mayo Clinic, “Time-dependent patterns of treatment effect and failure help explain the predictive role of deficient mismatch repair (dMMR) in Stage II and III colon cancer,” 06/08/2010
The Ohio State University Medical Center, Drug Information Center, “Irinotecan,”
Drug Digest: Camptosar
Drug Digest: Eloxatin Solution for Injection
University of Kentucky Health Information Library
University of Maryland Medical Center, “Colon and Rectal Cancers - Medications”
West Virginia University, Health Science Center, “Capecitabine - Xeloda”
Chemocare, “Side Effects - Symptoms & Solutions”
Mayo Clinic, “Cetuximab (Intravenous Route)”
Wikimedia Commons/United Federal Government/States Public Domain