Factors Associated With Receipt of Biomarker Testing Among Patients With Metastatic Colorectal Cancer

Significant variations exist in somatic biomarker testing across subgroups of patients with metastatic colorectal cancer (mCRC) and identification of genomic alterations can aid in ascertaining targeted treatment and in enhancing clinical outcomes; therefore, equitable usage of these testing strategies, particularly next-generation sequencing (NGS), is essential, according to findings from a recently published study (Cancer Med. 2022; 10.1002/cam4.4995. doi:10.1002/cam4.4995).

Sarah C Markt, Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine and Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, Ohio and colleagues conducted a retrospective review of de-identified patient data derived from electronic health records (EHRs) of 25,469 patients diagnosed with mCRC between the time frame of 2013 and 2020.

Dr Markt and colleagues aimed to explore possible variances in testing for mCRC by demographic and clinical factors. The outcome was a receipt of the following tests: (a) biomarker testing (BRAF, KRAS, NRAS, MMR/MSI) and (b) next-generation sequencing (NGS). They interrogated data using the machine-learning algorithm Classification and Regression Tree (CART), a unique approach to detecting combinations of, rather than individual demographic and clinical characteristics associated with receipt of testing.

Of the 25,469 patients identified with mCRC, 21,133 (83%) received either biomarker testing only (n = 12,485) or any testing (biomarker + NGS) (n = 8648). The percentage of patients who received any testing increased over calendar time for all age, race, and gender categories. Receipt of any testing was greatest (90%) among younger patients and patients with better performance status, and there was no difference in receipt of any testing by race. The greatest percentage of NGS testing was among those with better performance status, <70 years old, commercial or other governmental program payers, and low comorbidity burden; however, those who were African American or Hispanic had a lower prevalence of NGS testing than those who were Caucasian.

“There has been great progress in biomarker testing across demographic subgroups of patients with mCRC over the last several years,” wrote the authors, adding, “Future studies should be conducted utilizing real-world data sets to ensure greater utilization across each of these technologies for equitable access and delivery of cancer care.”

“More effort is needed to improve the uptake of NGS, especially among racially diverse patients, to improve the use of targeted therapy, representation in clinical trials, and to ensure equity in achieving the potential of precision oncology,” concluded Dr Markt and colleagues.