Related Experiment Video
Updated: Jun 14, 2025
Author Spotlight: Advancements in Molecular Biomarker Testing for Non-Squamous Non-Small Cell Lung Cancer
Published on: September 8, 2023
Methodological and TNM Focus-Based Comparison of EGFR Mutation Status in Non-Small-Cell Lung Carcinomas
1Department of Pathology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
Background:
Epidermal growth factor receptor (EGFR) mutations in non-small-cell lung carcinomas (NSCLC) are a frequent class of driver mutations, and tyrosine kinase inhibitor (TKI) therapy provides considerable clinical benefits. Using the most effective and also easiest method for EGFR analysis is cost-effective and time-saving. In this study, we aimed to determine which method could be more effective by comparing the incidences of EGFR mutations in cytological and histological samples which were obtained by different methods also, whether there was a difference in the incidences of EGFR mutations between the primary foci, mediastinal lymph nodes, and distant metastatic foci.
Materials And Methods:
We retrospectively reviewed 420 cases of cytological materials, small biopsies, and surgical samples reported as NSCLC underwent EGFR analysis in our department between 2016 and 2022. We collected the data and interpreted the results from two different perspectives.
Results:
We identified 36 EGFR mutations in 362 biopsies (9.94%) and 17 in 58 cytology samples (29.31%). There is a significant difference between the two methods (P = 0.01*). We observed 38 EGFR mutations in 320 primary foci (11.87%), 7 EGFR mutations in 36 mediastinal or subcarinal lymph nodes (19.44%), and 8 EGFR mutations in 64 distant metastatic foci (12.50%). A significant difference was also observed in pleural samples (P = 0.005*).
Conclusion:
We observed more successful results with cell blocks obtained from liquid-based cytological specimens than with formalin-fixed, paraffin-embedded tissues obtained from resection or otherwise in our clinical routine. Our study results highlight the benefits of cytological specimens in molecular treatments and current therapy modalities.
Insights
Cytological specimens are more effective for detecting epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer (NSCLC) than biopsies. This finding supports the use of cytology for guiding molecular treatments in NSCLC patients.
Area of Science:
- Oncology
- Molecular Diagnostics
- Pathology
Background:
- Epidermal growth factor receptor (EGFR) mutations are key drivers in non-small-cell lung cancer (NSCLC).
- Tyrosine kinase inhibitor (TKI) therapy offers significant clinical benefits for NSCLC patients with EGFR mutations.
- Efficient and cost-effective EGFR mutation analysis is crucial for guiding treatment decisions.
Purpose of the Study:
- To compare the effectiveness of cytological versus histological samples for EGFR mutation detection in NSCLC.
- To evaluate differences in EGFR mutation incidence across primary, nodal, and metastatic sites.
Main Methods:
- Retrospective review of 420 NSCLC cases (cytological, small biopsies, surgical samples) from 2016-2022.
- Analysis of EGFR mutation detection rates in cytological and histological specimens.
- Comparison of mutation frequencies in primary tumors, mediastinal lymph nodes, and distant metastases.
Main Results:
- EGFR mutations were detected in 29.31% of cytology samples versus 9.94% of biopsy samples (P=0.01).
- A significant difference in mutation detection was also observed in pleural samples (P=0.005).
- Mutation rates varied across different anatomical sites: primary foci (11.87%), lymph nodes (19.44%), and distant metastases (12.50%).
Conclusions:
- Cytological specimens, particularly cell blocks from liquid-based samples, show higher efficacy for EGFR mutation detection compared to traditional histological methods.
- These findings underscore the value of cytological samples in facilitating molecular-based treatments for NSCLC.
- Utilizing cytological specimens can optimize diagnostic yield and support personalized therapy selection in NSCLC management.
