170P - Survival of lung adenocarcinoma patients with uncommon EGFR mutations in routine clinical practice in Slovenia

Date 15 April 2016
Event European Lung Cancer Conference 2016 (ELCC) 2016
Session Poster lunch
Topics Anticancer agents
Non-Small Cell Lung Cancer
Therapy
Biological Therapy
Presenter Karmen Stanic
Citation Journal of Thoracic Oncology (2016) 11 (supplement 4): S57-S166. S1556-0864(16)X0004-4
Authors K. Stanic1, N. Turnsek Hitij2
  • 1Department Of Radiotherapy, Institute of Oncology Ljubljana, 1000 - Ljubljana/SI
  • 2Department Of Medical Oncology, University Clinic Golnik, 4204 - Golnik/SI

Abstract

Background

Tyrosine-kinase inhibitors (TKI) represent a standard in the treatment of advanced and metastatic non-small cell lung cancer (NSCLC) harboring EGFR mutations. Response rate was reported to be higher in most common (deletions of exon19 and L858R exon 21 substitutions), which usually represent 85–90% of all mutations. Optimal treatment and survival for rare mutations is still under investigation. We analyzed survival and treatment of rare EGFR mutations.

Methods

Medical records of all patients tested for EGFR mutations during 24 months period in routine clinical practice in Slovenia were analyzed. Median follow up period was 52 months.

Results

Among 137 EGFR mutated lung adenocarcinoma patients, surprisingly high percentage (24%, 33 patients) had rare mutations. Most common were exon 20 insertions (13%), followed by G719X point mutations in exon 18 (9%) and rare findings of point mutations in exon 20 (S768I) and exon 21 (L861Q), 1% of each. Patients with rare mutations were more common in men and significantly more common in smokers and patients with stage IIIB disease at diagnosis. Among all mutated patients, 98 had stage IIIB and IV disease and were therefore eligible for TKI treatment. Out of 76 patients with common mutations, 92% received systemic treatment (78% with TKI) but only 77% of 22 patients with rare mutations (72% with TKI). Median survival of patients harboring EGFR mutations and treated with TKI was 9.0 months (1.5–16.5) compared to 24.1 months (19.3–28.9) for common mutations (p = 0.08 for log rank test, p = 0.001 for Breslow test and p = 0.006 for Tarone-Ware).

Conclusions

Survival of patients with rare EGFR mutations in lung adenocarcinoma patients treated with systemic therapy in routine clinical practice was shorter than survival of patients with common mutations.

Clinical trial identification

National Ethics Committee number 143/10/11

Legal entity responsible for the study

Institute of oncology Ljubljana

Funding

Institute of oncology Ljubljana

Disclosure

All authors have declared no conflicts of interest.