Point-of-Care Testing Has Potential to Expand the Reach of NGS for CRC

Because more data are needed on the extent of benefits of comprehensive genomic profiling for patients with advanced colorectal cancer (CRC), via next-generation sequencing (NGS), investigators from William Osler Health System and the University of Toronto Department of Medicine investigated the biomarker testing method at the point of care.

“NGS is the laboratory cornerstone of precision oncology treatment,” the investigators noted. “However, in many jurisdictions, cancer patients are treated in publicly funded community hospitals, where NGS is not typically utilized and access to testing via send-out services is associated with lengthy turnaround times.”

Their findings were presented at the 2022 ASCO Gastrointestinal Cancers Symposium.

Using the Oncomine Precision Assay, NGS analyzed for biomarkers in 51 cases of CRC beyond the current standard-of-care recommendation, which encompasses testing for RAS, BRAF, and mismatch repair. All testing took place in a community immunohistochemistry lab between November 2020 and August 2021, and the findings were interpreted by anatomic pathologists. The authors also utilized retrospective chart reviews to gather data on patients’ sequencing studies, turnaround time for NGS results, and NGS findings.

Overall, 4 business days was the median turnaround time to receive NGS results, with 90% of cases having oncogenic driver events identified. Most cases (n = 28) received their results in 4 business days or less, with the remainder receiving their results in 5 or more business days.

The most common oncogenic driver events identified were KRAS (29.55%), TP53, (29.55%), and PIK3CA (10.23%). This included canonical mutations in KRAS, NRAS, and BRAF.

In addition, 25% of the 51 cases analyzed were shown to have these actionable mutations:

• KRAS amplification: 9.8%
• Atypical KRAS mutation (A146T, A146V, or K117N): 9.8%
• ERBB2: 5.9%
• ERBB3: 5.9%
• ERBB2 amplification: 2.0%
• ERBB3 amplification: 2.0%

For these actionable mutations, the investigators noted they would have gone undetected if not for the NGS. Single-gene testing would not have identified them, they emphasized.

“Traditional NGS operations are complicated, requiring specialized equipment and personnel,” they wrote. “To our knowledge, this is the fastest turnaround time reported for NGS in CRC, and it added valuable information compared to guideline-recommended testing standards.”

They concluded that it is possible to perform comprehensive NGS in a community setting by utilizing local testing and that this can help to shorten the turnaround time for results as well as reveal occult resistance mechanisms to standard treatment.

Still they recommend that follow-up studies continue to research optimal ways to expand NGS in community settings.

Reference

Raskin W, Cheema P, Perdrizet K, Iafolla M, Dudani S, Sheffiled B. Rapid point of care NGS in colorectal cancer. Presented at: ASCO Gastrointestinal Cancers Symposium; January 20-22, 2022; San Francisco, CA, and virtual; poster 172. Accessed January 24, 2022.