Chemotherapy Plus Either Bevacizumab or Cetuximab Are Equally Effective for Metastatic Colorectal Cancer

ASCO Annual Meeting
June 1, 2014

In a large, ongoing study, results indicate that two common treatment regimens approved by the U.S. Food and Drug Administration are equally effective for metastatic colorectal cancer. Metastatic colorectal cancer is cancer that has spread to other parts of the body.

Both of the treatments researched in this study include chemotherapy, but one adds the targeted therapy bevacizumab (Avastin) and the other adds the targeted therapy cetuximab (Erbitux). Targeted therapy is a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. Bevacizumab and cetuximab target cancer growth differently.

Additionally, for either the bevacizumab or the cetuximab regimen, two different but equally effective combinations of drugs may be used for chemotherapy. This includes the combination called FOLFOX, which is oxaliplatin (Eloxatin), 5-fluorouracil (5-FU, Adrucil), and leucovorin (Wellcovorin), or FOLFIRI, which is irinotecan (Camptosar), 5-FU, and leucovorin.

For this study, 1,137 patients with metastatic colorectal cancer who had not previously received treatment were given either bevacizumab plus chemotherapy or cetuximab plus chemotherapy. The drugs used for chemotherapy, either FOLFOX or FOLFIRI, were determined by the doctor providing care.

Researchers found that patients who received either treatment lived a similar amount of time and had a similar chance of the disease worsening. For those who received bevacizumab plus chemotherapy, it took about 11 months for the disease to worsen, and those patients lived almost two and a half years after diagnosis. For those who received the cetuximab regimen, it took about 10 months for the disease to worsen, and those patients also lived for about two and a half years after diagnosis. 

What this means for patients

“About 75% of patients with metastatic colorectal cancer in the United States initially receive bevacizumab-based therapy, although we know that cetuximab-based therapy is also a good option,” said lead author Alan P. Venook, MD, the Madden Family Distinguished Professor of Medical Oncology and Translational Research at the University of California in San Francisco. “Our findings clearly show that the two options -- with either FOLFOX or FOLFIRI -- are both acceptable and similarly effective.”

Costs of bevacizumab and cetuximab are similar but the side effects are slightly different. The side effects of FOLFOX and FOLFIRI are also different. When making treatment decisions, talk with your doctor about the side effects of your treatments and how they will affect your quality of life.

Questions to ask your doctor

  • What stage of colorectal cancer do I have? What does this mean?
  • Has it spread to other parts of the body?
  • What are my treatment options?
  • What are the risks and benefits of these options?
  • What are the side effects of each option, and how can they be managed?

For More Information

Guide to Colorectal Cancer

Making Decisions About Cancer Treatment

Targeted Treatments

Side Effects of Chemotherapy

Skin Reactions to Targeted Therapies