Oops, you're using an old version of your browser so some of the features on this page may not be displaying properly.

MINIMAL Requirements: Google Chrome 24+Mozilla Firefox 20+Internet Explorer 11Opera 15–18Apple Safari 7SeaMonkey 2.15-2.23

Poster display session: Biomarkers, Gynaecological cancers, Haematological malignancies, Immunotherapy of cancer, New diagnostic tools, NSCLC - early stage, locally advanced & metastatic, SCLC, Thoracic malignancies, Translational research

1865 - The characteristics and clinical outcome of metastatic NSCLC harboring uncommon EGFR mutation at Thailand's tertiary referral center.

Date

20 Oct 2018

Session

Poster display session: Biomarkers, Gynaecological cancers, Haematological malignancies, Immunotherapy of cancer, New diagnostic tools, NSCLC - early stage, locally advanced & metastatic, SCLC, Thoracic malignancies, Translational research

Topics

Targeted Therapy

Tumour Site

Presenters

Jomjit Chantharasamee

Citation

Annals of Oncology (2018) 29 (suppl_8): viii493-viii547. 10.1093/annonc/mdy292

Authors

J. Chantharasamee1, N. Poungvarin2, P. Danchaivijitr1, S. Techawatanawanna1

Author affiliations

  • 1 Medicine, Siriraj Hospital, Mahidol University, 10700 - Bangkok/TH
  • 2 Clinical Pathology, Siriraj Hospital, Mahidol University, 10700 - Bangkok/TH
More

Resources

Abstract 1865

Background

An uncommon EGFR-mutant NSCLC is a rare subset of NSCLC. Prevalence and clinical outcome of this entity remain unclear. Several studies have reported the benefit of EGFR-tyrosine kinase inhibitor in patients harboring complex or uncommon EGFR mutations but there are insufficient data to determine the advantage of EGFR-TKI over chemotherapy. This study aimed to review the prevalence and clinical outcome of treatment of uncommon EGFR-mutant patients in real-world practice.

Methods

We retrospectively reviewed medical records of 681 patients tested for EGFR mutation NSCLC during 2014-2018 to collect the mutational status and to compare the survival outcomes between the patients treated with EGFR-TKI and chemotherapy.

Results

At a median follow-up of 19.1 months, 317 (47%) patients were identified with EGFR-mutant NSCLC. Twenty-eight patients (8.8%) harbored uncommon EGFR mutations. Of those 28 patients, the most frequent single mutation was exon20 insertion (21%, n = 6); 5 were L861Q and 4 were G719X. 13 (46%) patients had compound mutations: 4 were G719X plus S768I; 4 were de novo T790M plus either L858R or deletion(del)19; 2 were L858R plus del19; 1 was L858R plus Ex20Ins; 1 was del19 plus KRAS mutation, and 1 with G719X plus E709A was found in squamous cell carcinoma. History of tobacco use was found in 50% of patients. 100% of male patients with G719X mutation were smokers. 57% of the 28 patients were treated with EGFR-TKI, mostly 1st generation, and 29% were treated with chemotherapy alone. The objective response rate was 56% in the TKI group. Median progression-free survival (PFS) in the TKI group was 10.2 months. 5-year overall survival (OS) rate was 34%. Patients treated with TKI had significantly better 5-year OS rate than those who had never received TKI (54% vs. 17%, 95%CI 1.23-14.66, p log-rank= 0.02). The longest OS was 73.6 months in a patient with del19 plus de novo T790M.

Conclusions

This study demonstrated the benefit of 1st generation EGFR-TKI was greater than with chemotherapy alone in the patients with uncommon or compound EGFR mutation NSCLC. Rare EGFR mutations can be detected in squamous cell carcinoma. There was a high prevalence of smoking among the male patients with G719X-mutant NSCLC.

Clinical trial identification

Legal entity responsible for the study

Jomjit Chantharasamee.

Funding

Has not received any funding.

Editorial Acknowledgement

The authors gratefully acknowledge Wichit and KemJira for assistance with patient’s data retrieval and statistical analysis.

Disclosure

All authors have declared no conflicts of interest.

This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

Customise settings
  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and you can only disable them by changing your browser preferences.