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R. Landreneau
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P3.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 235)
- Event: WCLC 2015
- Type: Poster
- Track: Biology, Pathology, and Molecular Testing
- Presentations: 1
- Moderators:
- Coordinates: 9/09/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
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P3.04-043 - Driver Mutations in Non-Small Cell Lung Cancer in Western Pennsylvania: Prevalence and Barriers to Testing (ID 1426)
09:30 - 09:30 | Author(s): R. Landreneau
- Abstract
Background:
EGFR gene mutations and EML4-ALK rearrangements are key therapeutic targets in nonsquamous non-small cell lung carcinoma (nsNSCLC). Therapy targeted towards these mutations has been shown to improve tumor response, progression-free survival, and quality of life. Current guidelines recommend testing all advanced (Stage IIIB and IV) nsNSCLC patients for these genetic aberrations. Despite this recommendation, not all patients eligible for mutation analysis are tested. In our institution, preliminary observations suggest the percentage of patients being tested and the frequency of driver mutations are significantly lower compared to published data. The purpose of the study was to review tumor registry data in order to determine the rate of testing and the frequency of driver mutations in Western Pennsylvania. Our secondary aim was to evaluate whether biopsy size impacts the frequency of EGFR and ALK testing.
Methods:
From the tumor registry, 167 cases of advanced nsNSCLC were identified (2011-2013). The testing rates for driver mutations, frequency of driver mutations, and the tissue procurement technique were determined by individual chart review. Surgical specimens, core biopsies, and large volume thoracentesis specimens were categorized as large tissue biopsies and samples obtained by fine needle aspiration, bronchial washing, and bronchial brushing were considered small tissue biopsies. Using a Chi-square analysis, mutation testing rates were compared between the large and small biopsy groups. Frequency of driver mutations was determined, excluding unknown or inadequate samples.
Results:
Of the 167 cases, there were 120 (71.9%) large and 47 (28.1%) small biopsy specimens. 61 (50.8%) large sample biopsies and 17 (36.2%) small sample biopsies were submitted for EGFR analysis. 39 (32.5%) large sample biopsies and 10 (21.3%) small sample biopsies were tested for ALK rearrangements. It was found that large tissue biopsies were more likely to be analyzed for EGFR mutations and ALK rearrangements although the results did not reach statistical significance (p=0.088 and p=0.150, respectively). Across all samples, a total of 7 EGFR mutations and 0 ALK rearrangements were identified representing a frequency of 10.0% and 0.0% respectively.
Conclusion:
Despite current guidelines for testing driver mutations in advanced nsNSCLC, we are testing less than 50% of our patients. There are several barriers that continue to thwart this recommendation, including failure to integrate driver mutation testing into routine pathology practice (i.e., reflex testing), lack of care coordination with relevant clinical specialties beyond medical oncology and pathology, and insufficient tissue obtained from biopsy. More importantly, these trends are not isolated to our institution and reflect a significant challenge within the oncology community. In the coming months, we will be initiating a Lean Six Sigma approach to modify our current clinical practice and improve our testing rate. In addition, we have begun using a blood based assay (liquid biopsy) to interrogate advanced nsNSCLC for driver mutations. We have also demonstrated that the frequency of driver mutations in Western Pennsylvania is lower than published data. Accession of additional patients to this data set continues and a final analysis will be presented.
