Chemotherapy can be given either as an individual drug (monotherapy) or as combination therapy where several chemo drugs and/or biologic agents are given together.
Drugs and biologic agents that may be given as monotherapy for colorectal cancer
- 5-FU (fluorouracil) may be given alone as a continuous infusion. When it is given as a short or bolus injection it is almost always combined with leucovorin (folinic acid) which improves its effectiveness.
- Xeloda® (capecitabine) is an oral drug that may be prescribed as the only drug used for chemotherapy.
- Camptosar® (irinotecan) or its generic version may be used either as monotherapy or in combinations.
- Erbitux® (cetuximab) may be given alone or in combinations.
- Vectibix® (panitumumab) is FDA approved as a single agent but is in clinical trials for combination use.
- Fluorouracil (5-FU), either as a continuous infusion or bolus injection, is given in combination with leucovorin (also called folinic acid) FULV. 5-FU/leucovorin also form the backbone of several other combinations.
- Eloxatin (oxaliplatin) is combined with continuous infusion 5-FU and leucovorin in the FOLFOX regimen. (FOLinic Acid, Fluorouracil and OXaliplatin).
- Xeloda (capecitabine) is an oral form of 5-FU that can be combined with oxaliplatin in the XELOX regimen (also known as CAPOX).
- Camptosar (irinotecan) can be combined with continuous infusion 5FU and leucovorin in the FOLFIRI regimen. (FOLinic acid, Fluorouracil, IRInotecan.
- Xeloda can be combined with irinotecan as XELIRI or CAPIRI.
- Reports of all drugs — continuous infusion 5-FU, leucovorin, irinotecan, and oxaliplatin — in the FOLFOXIRI combination showed better progression-free and overall survival in initial treatment of metastatic colorectal cancer in 2007.
Chemotherapy drugs combined with biologic agents
Avastin® (bevacizumab) can be combined with any of the 5-FU based combinations (FULV, FOLFOX, or FOLFIRI) for treating metatastic colorectal cancer. It is not normally prescribed to be used alone. Clinical trials are underway to evaluate its use in combination with FOLFOX as adjuvant treatment after surgery for earlier stages of colon cancer.
Erbitux® (cetuximab) can be combined with FOLFIRI or prescribed alone. Clinical trials are underway to evaluate its effectiveness to treat stage III colon cancer.
There are many clinical trials underway to evaluate safety, effectiveness, and side effects of various combinations, doses, and schedules of chemotherapy drugs and biologic agents.
Once a drug or biologic agent has been approved by the FDA, physicians can recommend its use “off-label” for indications that have not yet been included on the FDA-approved label. Sometimes there is good evidence from peer-reviewed and published randomized clinical trials for an off-label use. Sometimes evidence is lacking or even negative.
If your doctor recommends an off-label use for a drug or combination ask:
- What evidence are you basing your recommendation on?
- What is the evidence for safety for people like me?
- What other choices do I have?
Where Can You Go for More Information
The National Cancer Institute provides more specific details on combination treatment regimens in its health professional version of Colon Cancer Treatment PDQ®. This material is technical, but it provides additional information. Remember to talk over the details of your treatment with your own doctors.