Chemotherapy for metastatic colorectal cancer
Initial chemotherapy options
Choices for initial treatment of stage IV colorectal cancer or for earlier stage cancer that has spread (recurred or recurrent disease) have increased significantly in just the past few years. New treatments have dramatically increased the number of patients responding to treatment, survival time, and the possibility that tumors can be removed surgically and cured.
The right treatment depends on potential side effect profiles, an individual’s overall health, and the goals of treatment.
Studies have found that patients with the best survival time are exposed to all three active chemotherapy agents — 5-FU, Eloxatin (oxaliplatin), and Camptosar (irinotecan) during the total course of their treatment.
A randomized clinical trial has shown that the sequence of drug combinations — FOLFOX followed by FOLFIRI or vice versa — makes no difference in overall survival. Choice of the initial agent can be based on side effect profile or patient preference.
Some commonly used combination chemotherapy regimens for initial treatment for patients able to manage intensive treatment include:
- FOLFOX: Eloxatin® (oxaliplatin), continuous infusion 5-FU and leucovorin plus Avastin® (bevacizumab)
- FOLFIRI: Camptosar® (irinotecan), continuous infusion 5-FU and leucovorin plus Avastin.
- IFL: irinotecan and bolus 5-FU plus leucovorin. Because of its harsh side effects and poorer effectiveness, IFL has been largely replaced by FOLFIRI.
- XELOX (CAPOX) plus Avastin. Xeloda® (capecitabine) is an oral prodrug that works the same way as 5-FU inside the cancer cell.
Patients who are not able to tolerate intensive therapy have other options. Doctors may recommend:
- 5-FU plus leucovorin with or without Avastin. Continuous infusion 5-FU is more effective has fewer side effects than bolus 5-FU.
- Xeloda with or without Avastin. Treatment with Xeloda alone should only be considered a reasonable option for selected patients who are not candidates for more aggressive combination regimens with Eloxatin or Camptosar.
Randomized clinical trials that compare new drugs and new combinations or regimens of existing drugs to standard therapies are also an important choice for initial treatment of colorectal cancer.
If cancer progresses (begins to grow again) on initial therapy or the patient needs to stop treatment because of unacceptable side effects, a new regimen can be tried.
Treatment after first progression
- Switch to FOLFOX or CAPOX treatment, if not already given. Avastin can be added if not given with initial treatment.
- Switch to FOLFIRI treatment, if not already given.
- Camptosar® (irinotecan) can be used alone.
- Erbitux® can be used alone or in combination with irinotecan.
- Vectibix® (panitumumab) can be used alone or in combination with irinotecan.
- Clinical trials testing new therapies are a choice at this point in the treatment continuum.
Treatment after a second progression
- Erbitux plus Camptosar, even if Camptosar has already been used, combining it with Erbitux seems to restart its effectiveness.
- Erbitux alone (monotherapy).
- Vectibix (panitumumab) alone if there has not already been treatment with Erbitux, which acts in a very similar way.
- A clinical trial of a new agent or new treatment combination.
- Good supportive care to reduce cancer symptoms and increase overall quality of life.
Where Can You Go for More Information
NCCN/ACS Colon and Rectal Cancer: Treatment Guidelines for Patients have decisions trees that help patients and their doctors negotiate the choices available for chemotherapy treatment.
Last Update: June 29, 2008
Medical Review
This page is under review by C3's medical review network.
