Real-world ALK Testing Trends in Patients With Advanced Non-Small-Cell Lung Cancer in the United States

Patients with non-small-cell lung cancer (NSCLC) whose tumors harbor anaplastic lymphoma kinase (ALK) rearrangements can be treated with ALK tyrosine kinase inhibitors. We assessed real-world ALK biomarker testing and treatment patterns of patients with NSCLC in the United States.

Data were extracted from the Flatiron Health electronic health record-derived deidentified database for patients aged ≥18 years with stage IIIB or IV NSCLC and ≥2 clinic visits between January 2011 and December 2019.

Among 60,025 eligible patients, tumors from 36,691 (61.1%) patients were tested for ALK rearrangements, and 1042 (2.8%) tested positive (ALK+). From 2011 to 2019, ALK testing rates increased from 33.1% to 73.0%; testing via fluorescence in situ hybridization declined from 68.3% to 32.1% while next-generation sequencing increased from <1% to 52.2%. Although tissue samples were more commonly used than blood (85.1% vs. 13.5% of tests), blood sample testing increased from 0.1% in 2011 to 28.2% in 2019. Median (interquartile range) time from diagnosis of advanced NSCLC to first ALK+ test result was 23 (13-43) days, including laboratory processing time of 9 (6-14) days. For the 24.7% of patients with an ALK+ test result who began treatment before receiving the positive result, chemotherapy was initiated most often overall until 2018 when immuno-oncology agents became most common.

Although ALK testing in NSCLC increased over time, testing rates among eligible patients did not reach 100% during the study period. Treatment decisions for some patients with NSCLC may have been made without important, guideline-recommended biomarker data.