January 13, 2020
Less than half of patients with metastatic tumors have the recommended genomic profiling that forms the basis of precision oncology
Investigators at John Theurer Cancer Center (JTCC) at Hackensack University Medical Center in New Jersey are the first to report poor adherence to genomic profiling guidelines for four biomarkers of metastatic colorectal cancer used to predict response to therapy, choose the most effective treatment, and improve outcomes — showing that only 40% of patients had their tumors tested. The study was published online in the December 6, 2019 issue of JCO Precision Oncology, a publication of the American Society of Clinical Oncology (ASCO).
“Despite guidelines that recommend testing for four common biomarkers in patients with metastatic colorectal cancer, overall testing rates were suboptimal,” noted hematologist-oncologist Stuart L. Goldberg, M.D., Chief, Division of Outcomes and Value-Based Care at JTCC, Associate Professor of Medicine at Seton Hall School of Medicine, and senior author of the study. “We expected there to be better awareness of the guidelines with time and increased testing rates over the years, but that did not turn out to be the case.”
Genomic testing is recognized in national guidelines as essential to guide appropriate therapy selection in metastatic colorectal cancer. The presence or absence of mutations in genes such as RAS (KRAS and NRAS) and BRAF and genetic changes called microsatellite instability (MSI) can predict how well a patient will respond to metastatic colorectal cancer therapies such as cetuximab, panitumumab, and immunotherapy with pembrolizumab. Starting in 2009 and over the ensuing decade, ASCO and the National Comprehensive Cancer Network (NCCN) began publishing guidelines recommending routine genomic testing for KRAS, NRAS, BRAF, and MSI status in patients with metastatic colorectal cancer.
Studies published earlier have reported that adherence to testing guidelines was suboptimal, but current testing rates have not been assessed. Investigators at John Theurer Cancer Center retrospectively reviewed the COTA Real World Data database to identify patients with metastatic colorectal cancer diagnosed between 2013 and 2017. Among the 1,497 patients identified, testing for biomarkers according to the guidelines for RAS, BRAF, and MSI were 41%, 43%, and 51%, respectively. RAS and BRAF testing were more likely to be done in academic medical centers compared with community hospitals. Of 177 patients who received cetuximab or panitumumab — drugs indicated for the treatment of people with normal RAS genes — only 28% had undergone tumor testing for RAS status.
“When biomarker testing is underutilized, it places patients at risk of receiving ineffective therapies and may delay or prevent them from receiving appropriate therapeutic options,” explained lead author Martin E. Gutierrez, M.D., Chief of Thoracic Oncology and Director of Drug Discovery and the Phase I Unit at JTCC. “Adherence to guideline-recommended biomarker testing would potentially reduce exposure to expensive and ineffective therapies, resulting in more rationale care and improved patient outcomes.”
The investigators noted that possible barriers to biomarker testing may include availability of tumor tissue, turnaround time, physician knowledge, cost and insurance issues, patient preferences, and patient eligibility for therapy based on overall health.