Abstract 493P
Background
Epidermal growth factor receptor (EGFR) deletion of exon 19 and exon 21 mutations are the most common mutations in advanced non-small cell lung cancer (NSCLC) and predict higher sensitivity to EGFR tyrosine kinase inhibitors (TKI). The present study is a retrospective analysis of patients harboring EGFR exon 19 deletions and exon 21 mutations in advanced NSCLC.
Methods
Data of patients diagnosed with advanced NSCLC patients with EGFR mutations from January 2012 to March 2019 was analysed. EGFR mutation analysis was performed using DNA sequencing by real time polymerase chain reaction method. Exon 19 and exon 21 mutated patients were compared for clinicopathological features and outcomes.
Results
Data of 697 patients with lung cancer was retrieved of which 613 patients had advanced NSCLC. A total of 441 patients were evaluated for EGFR mutations and 135 (30.6%) patients were positive for EGFR mutations. The median age at presentation was 57.5 years(range, 30-88). Smoking history was seen in 38 (28.1%) patients and 97 (71.8%) were non smokers. Of these 135 patients with EGFR positivity, 129(95.6%) had adenocarcinoma histology and 6(4.4%) had adenosquamous histology. Exon 19 and exon 21 mutations accounted for 79(58.5%) and 45(33.33%) cases respectively. Mutations in exon 18, exon 20 and double mutations were seen in 2(1.4%), 3(2.2%) and 6(4.4%) patients respectively. Thirty nine (28.8%) patients received initial chemotherapy followed by switch maintenance. Geftinib (82.2%) was the most common TKI used followed by erlotinib (9.6%), Afatinib (4.5%), Osimeritinib (0.8%) and chemotherapy (2.9%). The clinical profile, treatment details and outcomes are tabulated below. The median PFS and OS were 8.9 months (range, 4-42 months) and 18 months (range,4-46 months) respectively.
Table: 493P
Overall EGFR Positive(n = 135) | Exon 19 deletions(n = 79) | Exon 21 Mutated (n = 45) | P Value | |
---|---|---|---|---|
Median Age (years) | 57.5 (range, 30-88) | 55 (range, 35-88) | 61 (range, 30-80) | |
Sex: Male Female Ratio | 75 60 1.25:1 | 44 35 1.25:1 | 25 20 1.25:1 | 0.98 |
Smoker: Yes No | 38 97 | 26 53 | 11 34 | 0.32 |
Metastases: Bone B/L lung Pleural effusion Brain Liver | 67 58 40 22 10 | 39 32 22 20 8 | 26 22 13 2 1 | 0.36 0.38 0.9 0.03 0.24 |
Rash Grade 1 Grade 2 Grade 3 | 37 20 10 7 | 23 8 10 5 | 13 11 0 2 | 0.8 |
Response evaluated Partial response Stable disease Progressive disease | 111 48 (43.3%) 49 (44.1%) 14 (12.6%) | 65 27 (41.6%) 31 (47.7%) 7 (10.7%) | 38 18 (47.4%) 16 (42.1%) 4 (10.5%) | 0.5 0.6 0.7 |
Median PFS (months) | 8.9 | 9.2 | 8.3 | 0.8 |
Median OS (months) | 18 | 18.9 | 17 | 0.5 |
Conclusions
In patients with EGFR-sensitizing mutations, tyrosine kinase inhibitors offer superior progression free survival and response rates and are well tolerated. Brain metastases at presentation were significantly higher in exon 19 compared to exon 21. No significant differences were observed in median PFS or median OS in EGFR exon 19 deleted or Exon 21 mutated subgroup.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Department of Medical Oncology, Nizam\'s Institute of Medical Sciences.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
357P - Application of multi-modal approach to palliation in end of life head and neck cancer pain
Presenter: Srujana Joga
Session: Poster display session
Resources:
Abstract
358P - Evaluation of continuous low dose versus standard dose capecitabine monotherapy as second/third-line chemotherapy for metastatic malignancies
Presenter: Swaroop Revannasiddaiah
Session: Poster display session
Resources:
Abstract
359P - Factors associated with economic burden among cancer patients with minor children: A cross-sectional web-based survey of an online cancer community
Presenter: Midori Yuki
Session: Poster display session
Resources:
Abstract
360P - Factors influencing treatment decisions among breast cancer patients in the Philippine general hospital cancer institute: Medical oncology outpatient clinic
Presenter: Bobby De Guzman
Session: Poster display session
Resources:
Abstract
361P - The role of volunteers in quality palliative care delivery
Presenter: NABANITA MANDAL
Session: Poster display session
Resources:
Abstract
362P - Survey to assess the efficacy of continuity of care delivered through an out of hours telephonic consultation liaison
Presenter: Rahul D. Arora
Session: Poster display session
Resources:
Abstract
366P - Activity of larotrectinib in TRK fusion cancer patients with primary central nervous system tumours
Presenter: David Ziegler
Session: Poster display session
Resources:
Abstract
367P - Molecular characteristics and efficacy of crizotinib among different subsets of MET Amplification detected by next-generation sequencing in lung cancer
Presenter: Jing Li
Session: Poster display session
Resources:
Abstract
368P - Genomic analysis of malaysian breast cancers unravel molecular differences from Caucasian breast cancers
Presenter: Soo-Hwang Teo
Session: Poster display session
Resources:
Abstract
369P - Institutional-based prospective molecular profiling of advanced solid tumours in Hong Kong: A report of 253 cases
Presenter: Herbert Loong
Session: Poster display session
Resources:
Abstract