Abstract
Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are first-choice treatments for advanced non-small-cell lung cancer patients harboring EGFR mutations. Although EGFR mutations are strongly predictive of patients’ outcomes and their response to treatment with EGFR-TKIs, early failure of first-line therapy with EGFR-TKIs in patients with EGFR mutations is not rare. Besides several clinical factors influencing EGFR-TKI efficacies studied earlier such as the Eastern Cooperative Oncology Group performance status or uncommon mutation, we would like to see whether semi-quantify EGFR mutation gene expression calculated by 2−ΔΔct was a prognostic factor in EGFR-mutant non-small cell lung cancer patients receiving first-line EGFR-TKIs. This retrospective study reviews 926 lung cancer patients diagnosed from January 2011 to October 2013 at the Kaohsiung Chang Gung Memorial Hospital in Taiwan. Of 224 EGFR-mutant adenocarcinoma patients, 148 patients who had 2−ΔΔct data were included. The best cutoff values of 2−ΔΔct for in-frame deletions in exon 19 (19 deletion) and a position 858 substituted from leucine (L) to an arginine (R) in exon 21 (L858R) were determined using receiver operating characteristic curves. Patients were divided into high and low 2−ΔΔct expression based on the above cutoff level. The best cutoff point of 2−ΔΔct value of 19 deletion and L858R was 31.1 and 104.7, respectively. In all, 92 (62.1%) patients showed high 2−ΔΔct expression and 56 patients (37.9%) low 2−ΔΔct expression. The mean age was 65.6 years. Progression-free survival of 19 deletion mutant patients with low versus high expression level was 17.07 versus 12.04 months (P = 0.004), respectively. Progression-free survival of L858 mutant patients was 13.75 and 7.96 months (P = 0.008), respectively. EGFR-mutant lung adenocarcinoma patients with lower EGFR gene expression had longer progression-free survival duration without interfering overall survival.
Original language | English |
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Pages (from-to) | 1-7 |
Number of pages | 7 |
Journal | Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine |
Volume | 39 |
Issue number | 3 |
DOIs | |
State | Published - 01 03 2017 |
Bibliographical note
Publisher Copyright:© 2017, © The Author(s) 2017.
Keywords
- EGFR mutation
- Lung cancer adenocarcinoma
- oncogene
- polymerase chain reaction (PCR)
- tyrosine kinase inhibitors