For patients with advanced non–small-cell lung cancer (NSCLC), immune checkpoint inhibitors have provided multiple effective treatment options. For those who do not have genetic mutations, the presence and level of PD-L1 expression are predictive of an increased response to anti–PD-1/PD-L1 therapy. The National Comprehensive Cancer Network recommends that patients who are newly diagnosed with advanced NSCLC undergo molecular testing for genetic mutations and PD-L1 expression. Although this testing is recommended, biomarker testing rates vary in clinical practice. In 2016, EGFR biomarker testing rates ranged from 59% to 61%, and the ALK biomarker testing rate was approximately 69%. In a 2018 retrospective study using a United States–based electronic health record database, the PD-L1 testing rate was 73%. Disparities in testing based on patient profile also appear to influence biomarker testing. Black patients, elderly patients, and patients without insurance or who are Medicaid recipients are less likely to be tested.
To determine the current rates of biomarker testing in patients with advanced NSCLC and to determine whether disparities in testing still exist, a study using a nationwide electronic health record database was performed using data from January 1, 2015, to October 31, 2021. The focus was on PD-L1 biomarker testing. The impact of biomarker testing on first-line treatment in patients with advanced NSCLC was also investigated. Data from 30,631 patients were available. Patients were newly diagnosed with advanced NSCLC as confirmed by pathology reports and had started treatment within 90 days of diagnosis. The median age at first diagnosis was 69 years, 68.2% of patients were White, and 47.5% were women. Nonsquamous histology was found in 69% of patients, and 86.9% of patients had a smoking history. A total of 48.1% of patients had commercial insurance, and 90.2% were managed in a community oncology setting. By study cutoff, 60% of patients were tested for 6 biomarkers and 90% were tested for at least 1 of the 6 biomarkers examined.
Biomarker testing increased during the study period with a dramatic increase found in PD-L1 testing from 2016 (16%) to 2017 (72%), then plateauing at 80% after 2018. The most commonly used assay for PD-L1 testing after 2020 was 22C3. For other biomarkers, rate increases ranged from 27% to 74% for KRAS, 35% to 80% for ROS1, 21% to 77% for BRAF, 61% to 81% for ALK, and 65% to 80% for EGFR. Older patients, patients with squamous-cell carcinoma, patients with Medicare coverage, Black patients, and those with recurrent disease were less likely to have PD-L1 testing. Patients with distant metastasis to the liver, brain, or bone were more likely to be tested than patients with no metastasis to those sites. Patients who had biomarker and PD-L1 testing had a longer time to next treatment and overall survival compared with patients who did not undergo testing. A stronger benefit was seen for patients tested for both PD-L1 and biomarkers.
Source: Wu N, Ge W, Quek RG, et al. Trends in real-world biomarker testing and overall survival in US patients with advanced non-small-cell lung cancer. Future Oncol. 2023 Jan 19. Epub ahead of print.
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