The American Society for Clinical Oncology (ASCO) has published a provisional clinical opinion (PCO) advising doctors to test patients with colorectal cancer for KRAS mutations before treating them with medicines that include Erbitux® (cetuximab) or Vectibix™ (panitumumab).
The consensus of experts who reviewed recent research was that patients with metastatic colorectal cancer whose tumors have mutations in the KRAS gene do not benefit from treatment that targets the epidermal growth factor receptor (anti-EGFR therapy). Patients should be tested for KRAS mutations and, if those mutations are found, not receive anti-EGFR antibodies as part of their treatment..
A PCO, based on expert consensus, is designed to help decision-making for oncologists faced with major research results that can potentially change the way they treat patients.
The expert panel wrote in the Journal of Clinical Oncology
Provisional Clinical Opinion: 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.
The opinion is based on five randomized clinical trials that evaluated patient outcomes in relation to KRAS status — either mutated or normal (wild-type). In addition, another five single-arm studies reviewed tumor changes depending on whether or not the tumor had mutated KRAS.
C3:Colorectal Cancer Coalition patient advocate Dr. Pamela K. McAllister was a member of the expert panel.
In an accompanying editorial Daniel G. Haller, M.D. and John V. Cox discuss reasons for developing the Provisional Clinical Opinion, the first issued by ASCO.
The purpose of PCOs is to provide ASCO members with direction on issues that have been informed by recent data that should affect clinical practice, such as KRAS testing. The need for timely opinion from ASCO is apparent as science becomes ever more complex and the pace of change increases. Additionally, the demands of clinical practice make it difficult for oncologists to stay abreast of many of these changes. ASCO President Richard L. Schilsky, MD, recently commented that the goal of the PCO is to answer a member’s query after hearing new data, “Does this change my practice?”
SOURCE: Allegra et al., Journal of Clinical Oncology, Volume 27, Number 12, April 20, 2009.