Gene fusions are genetic alterations thought to drive tumor growth. The Caris test can differentiate between fusion types and distinguish fusions from other rearrangements.

Next-generation sequencing is helping oncologists understand the genetic changes driving cancer progression. Clinical labs have rapidly adopted the cancer testing method for its potential to accelerate the development of personalized treatments to improve patient outcomes. It is being used in molecular oncology applications ranging from sequencing entire tumor genomes for clinical research to targeted clinical diagnostic gene panels, according to an overview of practice guidelines for the tests published in the Journal of Molecular Diagnostics.

The Caris assay is a next-generation sequencing-based test that uses RNA isolated from formalin-fixed paraffin embedded tissue specimens to detect all classes of structural rearrangements, including fusions, deletions, inversions and duplications, the company said.

RNA sequencing is becoming more common as a technique for cancer gene expression profiling as it becomes cheaper. Caris said its test is able to measure gene expression, the process by which a gene gets turned on in a cell to make RNA and proteins, to classify tumors. The test also can quantify splice variants that contribute to the development of cancer.

Last month, FDA cleared the first FGFR inhibitor for any cancer type with the approval of Johnson & Johnson’s Balversa to treat patients with metastatic or locally advanced bladder cancer whose tumors have alterations in the FGFR gene.

CMS reimbursement policy for NGS testing is in flux. The agency last month reopened its national coverage determination following pressure from healthcare organizations arguing the initial decision would deny access to the tests for Medicare beneficiaries with early-stage cancer. Gene sequencing platform leaders Illumina and Thermo Fisher Scientific and test provider Myriad Genetics are among those pushing for broader coverage.