Abstract 2000P
Background
In advanced NSCLC, determination of the EGFR mutation status at diagnosis and at progression (T790M) is crucial for making a treatment decision. In clinical practice however, molecular testing deals with several challenges. Here we describe real-world testing patterns for these patients in Belgium.
Methods
In this retrospective, multicentre, Belgian study (REVEAL) 141 patients diagnosed with advanced EGFR mutated NSCLC between 1/09/2015 and 31/12/2017 were investigated for demographics, disease characteristics, treatment patterns, patient outcomes, EGFR testing at diagnosis and T790M testing after progression on a first 1st or 2nd generation EGFR-TKI. Patients were observed until 1 Sep 2018 or end of clinical activity/death.
Results
At diagnosis, in 89% of patients 1 test was sufficient to obtain a positive EGFR result. 41% had an exon 19 deletion, 30% a L858R mutation, 2% a T790M de novo mutation and 29% a rare mutation only. 75%, 17% and 8% of tests were performed on tissue, cytology or liquid biopsy samples, respectively. The median time to a first positive result from diagnosis was 15 calendar days. In-house and external tests had a similar time to result (TTR). At progression, repeat testing was more frequent: In 2nd line 70% of patients underwent 1 test, 27% 2 tests and 2.7% 4 tests. In 3rd line 77% of patients underwent 1 test and 23% 2 tests. 45% of samples used at progression were tissue biopsies and in 38% and 15% of tests, liquid biopsies and cytology samples were used respectively. 72% (47/65) of patients were tested for T790M after progression and 53% (25/47) were positive. The median TTR at progression was 17 calendar days.
Conclusions
These data show that in real-world practice in Belgium, TTR is in line with European and Belgian guidelines but slightly longer at progression due to repeated testing. Liquid biopsy is well integrated in the testing algorithm and multiple test attempts are used to obtain a T790M result at progression, however nearly 30% of patients remain untested after progression. The T790M positivity rate of 53% is in line with earlier observations. The high percentage of patients with rare mutations only at diagnosis is surprising and needs further investigation.
Clinical trial identification
D5161R00007; NCT03761901.
Editorial acknowledgement
Legal entity responsible for the study
AstraZeneca.
Funding
AstraZeneca.
Disclosure
K. Cuppens: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca; Advisory/Consultancy, Travel/Accommodation/Expenses: Bristol-Myers Squibb; Advisory/Consultancy, Travel/Accommodation/Expenses: Hoffman-La Roche; Advisory/Consultancy, Travel/Accommodation/Expenses: Merck Sharp & Dohme; Advisory/Consultancy, Travel/Accommodation/Expenses: Pfizer; Advisory/Consultancy, Travel/Accommodation/Expenses: Boehringer-Ingelheim; Advisory/Consultancy: Merck Serono. L. Lodewyckx: Full/Part-time employment: AstraZeneca. I. Demedts: Honoraria (self), Honoraria (institution), Advisory/Consultancy, Research grant/Funding (institution): AstraZeneca. L. Decoster: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca; Travel/Accommodation/Expenses: F. Hoffman-La Roche; Travel/Accommodation/Expenses: Merck Sharp & Dohme; Research grant/Funding (institution): Boehringer-Ingelheim. B. Colinet: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca; Honoraria (self), Travel/Accommodation/Expenses: Bristol-Myers Squibb; Honoraria (self), Travel/Accommodation/Expenses: F. Hoffman-La Roche; Honoraria (self), Travel/Accommodation/Expenses: Merck Sharp & Dohme; Honoraria (self), Travel/Accommodation/Expenses: Pfizer; Honoraria (self), Travel/Accommodation/Expenses: Boehringer-Ingelheim; Honoraria (self), Travel/Accommodation/Expenses: Bayer. K. Deschepper: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca; Honoraria (self): F. Hoffman-La Roche; Honoraria (self): Merck Sharp & Dohme; Honoraria (self): Boehringer-Ingelheim; Honoraria (self): Bristol-Myers Squibb. A. Janssens: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca; Travel/Accommodation/Expenses: F. Hoffman-La Roche. P. Pauwels: Honoraria (self), Research grant/Funding (institution): AstraZeneca; Honoraria (self), Research grant/Funding (institution): F. Hoffman-La Roche; Honoraria (self), Research grant/Funding (institution): Boehringer Ingelheim; Honoraria (self), Research grant/Funding (institution): Bayer; Honoraria (self): Pfizer. D. Galdermans: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca; Honoraria (self): Chiesi; Honoraria (self): F. Hoffman-La Roche; Honoraria (self): Merck Sharp & Dohme; Honoraria (self): Boehringer-Ingelheim;. T. Pieters: Honoraria (self), Honoraria (institution), Advisory/Consultancy: AstraZeneca.