ASCO: Patients with mCRC eligible for cetuximab should be tested for KRAS mutations

Routine KRAS testing could save estimated $604 million annually.

2009 Gastrointestinal Cancers Symposium

The American Society of Clinical Oncology has issued a Provisional Clinical Opinion recommending KRAS testing for all patients diagnosed with metastatic colon cancer who are eligible for treatment with cetuximab. The opinion was issued in response to a study presented prior to the 2009 Gastrointestinal Cancers Symposium.

Veena Shankaran, MD, a postdoctoral fellow at the Veterans Administration Center for the Management of Complex Chronic Care and Northwestern University’s Robert H. Lurie Comprehensive Cancer Center, presented study results that showed that the routine screening of patients with metastatic colorectal cancer for KRAS mutations prior to treatment with cetuximab (Erbitux, ImClone) could save as much as $604 million a year in the United States.

“Recent studies have shown that the benefits seen with cetuximab are limited to patients with the wild-type, or normal, KRAS and are not seen in patients with the mutated KRAS gene,” Shankaran said. “In addition to preventing significant toxicities and ineffective therapies, routine use of KRAS testing will result in significant costs savings for the health care system by tailoring the use of cetuximab to patients who will actually benefit from the drug.”

Shankaran and her colleagues created an economic model to estimate the costs savings associated with routine KRAS testing. They estimated that testing the 28,724 patients diagnosed with metastatic colorectal cancer each year would cost $13 million, assuming a cost of $452 per patient. The average treatment cost of cetuximab is about $61,279 per patient. By not treating the estimated 35% to 46% of patients with colorectal cancer who have KRAS mutations and will not benefit from cetuximab there could be a net savings of $604 million.

This estimate did not include the possible cost savings associating with avoiding treatment and hospitalization for the adverse events associated with cetuximab.

Provisional Clinical Opinion

Jennifer C. Obel, MD, a gastrointestinal cancers specialist at NorthShore University HealthSystem, said ASCO has issued a Provisional Clinical Opinion in response to the growing body of evidence showing that EGFR inhibitors are only effective in patients with wild-type KRAS.

“Dr. Shankaran’s findings indicate that hundreds of millions of dollars could be saved by testing colorectal cancer patients’ tumors for KRAS mutations and then deciding on therapy based on these results,” Obel said. “This type of study is quite timely when you consider that cancer care costs are growing at an average rate of 15% per year. This is nearly three times the rate that overall health care costs increased in 2007.”

The opinion reads, “Based on systematic reviews of the relevant literature, all patients with metastatic colorectal carcinoma who are candidates for anti-EGFR antibody therapy should have their tumor tested for KRAS mutations in a CLIA-accredited laboratory. If KRAS mutation in codon 12 or 13 is detected, then patients with metastatic colorectal carcinoma should not receive anti-EGFR antibody therapy as part of their treatment.”

“Costs place a significant burden on our patients, especially those with limited finances,” Obel said. “We can base cancer treatment on unique genetic characteristics of the tumor and avoid unnecessary costs. As importantly, it improves patient outcomes and avoids side effects in those who will not benefit.” – by Jason Harris

For more information:

Shankaran V. Economic implications of KRAS testing in metastatic colorectal cancer (mCRC). Presented at: 2009 Gastrointestinal Cancers Symposium; Jan. 15-17, 2009; San Francisco.