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Alexander Drilon, MD

Gregory J. Riely, MD, PhD


How Often Are Oncologists Testing for NTRK Gene Fusion and Using Results to Modify Treatment?

By: Vanessa A. Carter, BS
Posted: Thursday, June 30, 2022

Andrew J. Klink, PhD, MPH, of Cardinal Health, Dublin, Ohio, and colleagues evaluated whether the timing of NTRK gene fusion testing correlates with treatment modifications among patients harboring TRK fusions. Published in Targeted Oncology, the results of this study, which are based on a one-time physician questionnaire, suggest that additional work be performed to understand why 46% of oncologists would not use TRK inhibitors following NTRK-positive status confirmation, despite approximately 90% of surveyed oncologists reporting they reviewed relevant clinical guidelines.

“Among TRK fusion cancers, medical oncologists most frequently reported testing for NTRK gene fusions at diagnosis or prior to first-line therapy,” mentioned the investigators. “Since less than one-third of oncologists report that Eastern Cooperative Oncology Group performance status, tumor type, or patient age constitute factors that determine whether to test for NTRK gene fusions, further research is needed to identify physicians’ rationale for NTRK gene fusion testing.”

A one-time physician questionnaire was completed by 28 community-based medical oncologists from the Oncology Provider Extended Network who treated a total of 148 patients with NTRK-positive, advanced, or metastatic solid tumors. The survey was a retrospective, multisite patient chart abstraction of oncology practices in the United States that focused on clinical, demographic, and NTRK gene fusion testing characteristics.

The most commonly reported tumor types were lung (27%), thyroid (18%), salivary gland (14%), and colorectal (12%). Most clinicians reported testing NTRK status prior to first-line therapy (68%); testing after disease progression on first-line, second-line, and third-line treatments was performed in 36%, 25%, and 21% of individuals, respectively. Of note, there appeared to be no difficulty reported in interpreting reports on this testing among most oncologists (96%).

Next-generation sequencing was the most common method of testing to determine NTRK status (96%); fluorescent in situ hybridization was the second most common method (29%). In addition, just over half of surveyed oncologists (57%) determined that tumor type, age, and performance status did not influence their NTRK testing decisions.

Disclosure: For full disclosures of the study authors, visit

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