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T. Chou
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P1.21 - Poster Session 1 - Diagnosis and Staging (ID 169)
- Event: WCLC 2013
- Type: Poster Session
- Track: Prevention & Epidemiology
- Presentations: 1
- Moderators:
- Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level
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P1.21-002 - A survey of EGFR mutation frequency and testing practices in Asia Pacific (ID 1213)
09:30 - 09:30 | Author(s): T. Chou
- Abstract
Background
The efficacy of EGFR TKIs in EGFR mutation-positive NSCLC patients has led to a need for accurate, timely EGFR mutation testing worldwide. Although EGFR mutation testing has been adopted by many laboratories in Asia, accurate data are lacking on the proportion of NSCLC patients tested in each country, and the most commonly used testing methods. The objectives are to investigate the practice of EGFR mutation analysis in Asian Pacific countries and document the prevalence of routine testing in this population.Methods
This is a retrospective database survey of records from NSCLC patients tested for EGFR mutations from 1 January 2011 to 1 January 2012 at participating sites across the Asia Pacific region. The majority of eligible hospitals/laboratories that participated had performed ≥ 100 EGFR mutation tests during that period. Accessible patient records were used to complete an online questionnaire, with data being stored in a central database. Primary objectives were to determine the number of NSCLC patients tested for EGFR mutations and the rate of EGFR mutation positivity: overall, by histological subtype, and by demography. Other variables included the number of NSCLC cases diagnosed, EGFR mutation testing methods used, and tumour sample characteristics and processing. The proportion of EGFR mutation-positive patients and 95% CI were calculated; other variables will be summarized descriptively. An interim analysis has been conducted using data collected from more than 18,000 newly diagnosed NSCLC patients at 29 sites.Results
The data from surveyed sites indicates that the overall proportion of NSCLC patients tested for EGFR mutations was 31.9% (95% CI 31.2-32.6%), with an EGFR mutation positivity rate of 40.2% (95% CI 39.1-41.4%) overall, ranging from 28.7% to 53.4% (Table). Additional data on demographic and histological subgroups and current testing practices (methods, sample types, sample preparation) will be presented. [*: Wilson score confidence interval. **: Note that the sites from Vietnam (one site) and Philippines (one site) did not test ≥ 100 patients. N.D.: No data.]Table: Proportion of Patients Tested and EGFR Mutation Rates at Participating Sites
Country Total number of newly diagnosed NSCLC patients Proportion of patients tested, % (95% CI*) EGFR mutation positivity, % (95% CI*) Total 18,050 31.9 (31.2-32.6) 40.2 (39.1-41.4) Japan 2,379 64.8 (62.9-66.7) 30.2 (28.0-32.6) China 12,086 18.3 (17.6-19.0) 38.1 (36.3-39.9) Taiwan 2,530 52.9 (50.9-54.8) 53.4 (50.7-56.0) Hong Kong 399 31.1 (26.7-35.8) 49.2 (40.6-57.9) Malaysia 357 98.6 (96.8-99.4) 45.7 (40.6-51.0) Thailand 249 57.8 (51.6-63.8) 45.1 (40.6-49.8) Vietnam** 50 100.0 (92.9-100.0) 36.0 (24.1-49.9) Philippines** N.D. Not Known 38.9 (29.5-49.2) Indonesia N.D. Not Known 28.7 (20.8-38.2) Conclusion
The data collected in this survey indicate that, in 2011, testing practices varied widely across the region, despite the well-known high incidence of the mutation. The data provide an insight into these practices and provide a reference platform on which to compare and build on for the future of EGFR mutation testing and molecular diagnosis of NSCLC in Asia Pacific.
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P3.11 - Poster Session 3 - NSCLC Novel Therapies (ID 211)
- Event: WCLC 2013
- Type: Poster Session
- Track: Medical Oncology
- Presentations: 1
- Moderators:
- Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level
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P3.11-004 - A Prospective Study of the Use of Circulating Markers as Predictors for Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor Treatment in Pulmonary Adenocarcinoma (ID 726)
09:30 - 09:30 | Author(s): T. Chou
- Abstract
Background
The use of liquid tissue, such as circulating cells or free DNA, to predict treatment response is attracting more attention.Methods
Patients with stage IV adenocarcinoma of the lungs who were going to receive gefitinib or erlotinib treatment were included. Both tumor tissue and plasma specimens were prospectively collected before treatment and analyzed using the ARMS-Scorpions method for EGFR mutation status analysis. The numbers of circulating CD146+/CD3- cells (as circulating endothelial cells, CECs), CD34+/CD45- cells (as endothelial progenitor cells, EPCs), and CD133+ cells (as circulating cancer stem cells, CSCs) were measured with flow cytometry. From June 2010 to July 2012, 112 consecutive patients were enrolled.Results
Eighty of the 112 patients had tissue EGFR (tEGFR) activating mutations. Plasma EGFR (pEGFR) activating mutations were detected in 24 of 80 patients with tEGFR activating mutations. There were lower CEC, EPC, and CSC counts in tEGFR mutated patients than in wild-type patients (p=0.001, 0.012, and 0.001, respectively). Progression-free survival (PFS) was best in those with only tEGFR mutations (n=56, median 16.8 months), followed by those with both tEGFR and pEGFR mutations (n=24, median 7.9 months), and worst in EGFR wild-type patients (n=32, median 2.1 months) (p<0.0001). PFS was significantly longer in patients with low CEC and low CSC counts than in those with high cell counts (p=0.0023 and 0.0053, respectively). Multivariate analysis showed that the presence of pEGFR was a poor prognostic factor, but not the presence of other markers.Conclusion
The presence of pEGFR mutation is a poor prognostic factor for patients with tEGFR mutations when they receive EGFR-TKI treatment. EGFR wild-type patients had higher counts of CECs, EPCs, and CSCs. These circulating markers are useful in predicting EGFR-TKI treatment efficacy, but less useful than pEGFR detection.
