Rates of ALK testing in patients with advanced non-small cell lung cancer (NSCLC) have increased over time, according to a real-world study published in Clinical Lung Cancer.
However, the study suggests that some patients are still not being tested, and others start treatment before receiving their results. In 2019, 27% of patients did not undergo ALK testing. Over the entire study period, about 25% of patients who tested ALK-positive started treatment before receiving their test results.
The study included data from 60,025 patients from the Flatiron Health electronic health record database who had 2 or more clinic visits during 2011-2019. All patients had stage IIIB-IV NSCLC. A majority (69.1%) had non-squamous NSCLC, and most (61.8%) had stage IV disease at diagnosis.
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Overall, 61.1% of patients (n=36,691) underwent ALK testing, and 2.8% of those tested (n=1042) were positive for ALK rearrangements.
The rate of ALK testing increased over the study period, from 33.1% in 2011 to 73.0% in 2019. The use of next-generation sequencing for ALK testing increased from 0.2% of tests in 2011 to 52.2% in 2019. The use of fluorescence in situ hybridization decreased, from 83.8% in 2012 to 32.1% in 2019.
For the entire study period, the majority of sample types were solid tissue (85.1%). However, the percentage of tests using blood samples increased from 0.1% in 2011 to 28.2% in 2019.
For the entire period, the turnaround time for ALK test results was a median of 23 days overall — 22 days for tissue samples and 30.5 days for blood samples.
Treatment Patterns
Of the 983 evaluable patients who had at least 1 ALK-positive test result, 243 (24.7%) started therapy before receiving their result. Of the 243 patients, 194 (79.8%) were treated with an ALK TKI, including 123 (85.4%) patients who had originally started chemotherapy.
A total of 742 patients (75.5%) started an ALK TKI after receiving an ALK-positive test result. The median number of days from a positive result to starting ALK TKI treatment was 22 days. Among patients who started treatment before receiving their ALK-positive results, the treatment latency was a median of 32.5 days.
Among the patients who had ALK-positive disease but had not received their test result prior to starting therapy, treatment patterns changed over time. Chemotherapy was the most common treatment from 2011 to 2016, immunotherapy and chemotherapy were both commonly used in 2017, and immunotherapy became the most commonly used treatment from 2018 to 2019.
“This real-world analysis revealed that testing for ALK rearrangements increased over time but had not reached 100% by the end of the study period (2019), despite treatment guideline recommendations,” the researchers concluded. “There is an unmet need for comprehensive and timely biomarker testing to ensure necessary molecular data is available for therapeutic planning.”
Disclosures: This study was supported by Takeda Development Center Americas, Inc. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Reference
Lin HM, Wu Y, Yin Y, et al. Real-world ALK testing trends in patients with advanced non-small cell lung cancer in the United States. Clin Lung Cancer. Published online October 12, 2022. doi:10.1016/j.cllc.2022.09.010
