Background
The majority of metastatic non–small cell lung cancer (NSCLC) in the US is treated in the community. A prospective observational study of stage IV NSCLC and extensive-disease SCLC (CA209-118) is being conducted across ∼70 US-community sites to understand testing and treatment patterns. This sub-study investigates biopsy and biomarker testing practices in stage IV NSCLC patients to understand the factors that may impact access to treatments when biomarker testing is required.
Methods
Data from patients enrolled prior to June 2016 with lung cancer diagnosis since April 2004 were abstracted from medical records into electronic case report forms. Of 1655 NSCLC patients enrolled, 1542 patients with documented dates of diagnosis and defined biopsy methods were eligible for this sub-study. Detection of programmed death-ligand 1 (PD-L1) utilized the 28-8 antibody (Dako, Carpinteria, CA) according to the diagnostic label.
Results
Approximately 75% of NSCLC patients are initially diagnosed with stage IV disease in the community setting, with only ∼50% patients tested for ALK and ∼60% patients tested for EGFR at any point during their cancer care despite testing recommendations in treatment guidelines. Biomarker testing rates may be influenced by sample availability and quality. Biopsy methods varied at initial diagnosis, with 40% of patients receiving fine-needle aspirates (FNAs; 26%) or other cytology-based methods (14%). Of these patients, a small percentage (∼7%) were documented to have received subsequent core-needle or resection biopsies up to 45 days following stage IV diagnosis. Selection of biopsy method was strongly influenced by the stage at diagnosis, with FNA and cytology-based methods used more commonly in advanced-disease stages. To evaluate whether FNA samples are amenable to PD-L1 IHC testing, a cohort of NSCLC tumor specimens is currently being analyzed. Early results suggest that FNA sample failure rates due to minimal tissue requirements and PD-L1−expression frequencies are comparable to resection and core-needle biopsies. Updated results will be presented.
Conclusion
Despite guidelines, ∼40% of stage IV NSCLC patients treated in the community are not receiving EGFR/ALK biomarker testing. Less invasive biopsy practices, including FNAs and other cytology methods, are more frequent in stage IV disease. Current PD-L1 IHC tests have not been evaluated in such samples. Preliminary results suggest that FNAs may be amenable to PD-L1 IHC testing, but further studies are required. As the treatment landscape evolves, education across the patient care continuum is critical to ensure that quality samples are obtained for biomarker analysis, enabling patient access to the broadest spectrum of treatment options.
Article info
Identification
Copyright
© 2016 Published by Elsevier Inc.
User license
Elsevier user license | How you can reuse 
Elsevier's open access license policy
Elsevier user license
Permitted
For non-commercial purposes:
- Read, print & download
- Text & data mine
- Translate the article
Not Permitted
- Reuse portions or extracts from the article in other works
- Redistribute or republish the final article
- Sell or re-use for commercial purposes
Elsevier's open access license policy
