EBUS-TBNA provides highest RNA yield for multiple biomarker testing from routinely obtained small biopsies in non-small cell lung cancer patients - a comparative study of three different minimal invasive sampling methods.
Author(s): Schmid-Bindert G, Wang Y, Jiang H, Sun H, Henzler T, Wang H, Pilz LR, Ren S, Zhou C
Publication: PLoS One, 2013, Vol. 8, Page e77948
PubMed ID: 24205040 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of biopsy method on RNA yield and the effects of histological subtype, patient gender, and smoking on the incidence of epidermal growth factor receptor (EGFR) mutations and levels of three molecular markers in non-small cell lung carcinoma (NSCLC).
Conclusion of Paper
The RNA yield was significantly higher from endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) biopsies than endobronchial biopsy forceps via fiberoptic bronchoscope specimens (28.9 ng/µL versus7.2 ng/µL), but was comparable to computed tomography (CT) -core needle biopsy specimens. EGFR mutations occurred at a higher rate in adenocarcinoma than squamous cell carcinoma specimens or specimens without a histological subtype specified, in females than males, and in non-smokers than smokers. Levels of excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M1 (RRM1), and BRCA 1 were not significantly different among the histological subtypes but ERCC1 levels were lower in patients with an EGFR mutation (P=0.013).
Studies
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Study Purpose
This study investigated the effects of biopsy method on RNA yield and the effects of NSCLC histological subtype, patient gender, and smoking on the incidence of EGFR mutations and expression levels of ERCC1, BRCA1 and RRM1. Biopsies were obtained from 106 patients with confirmed NSCLC by endobronchial biopsy forceps via fiberoptic bronchoscope (45 patients), EBUS-guided TBNA (33 patients), and CT-guided biopsy (23 patients). Biopsy method was determined by location of the tumor. Each biopsy was split into two parts, half was formalin-fixed and paraffin-embedded (FFPE) for histological subtyping and the other half was placed in RNAlater and stored at 4˚C. RNA and DNA were obtained from RNAlater preserved specimens using Allprep DNA/RNA mini kit, quantified by spectrophotometer, and stored at -80˚C.
Summary of Findings:
The RNA yield was significantly higher from EBUS-TBNA than bronchoscopy specimens (28.9 ng/µL versus7.2 ng/µL, P=0.005), but was comparable to CT-core biopsy specimens. Of the 25 specimens with EGFR mutations, 80% were adenocarcinoma. EGFR mutations occurred at a higher rate in adenocarcinoma specimens than in squamous cell carcinoma specimens or NSCLC-not otherwise specified specimens (40.8% versus 7.9% and 14.3%), in females than males (54.2% versus 15.7%, P<0.001), and in non-smokers than smokers (35.9% versus 17.7%, P=0.04). Levels of ERCC1, RRM1, and BRCA 1 were not significantly different among the histological subtypes but ERCC1 levels were lower in patients with an EGFR mutation (P=0.013).
Biospecimens
Preservative Types
- Formalin
- RNAlater
Diagnoses:
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform DNA SNP assay DNA Real-time qPCR Morphology H-and-E microscopy RNA Real-time qRT-PCR RNA Spectrophotometry DNA Spectrophotometry Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Real-time qRT-PCR Specific Targeted nucleic acid RRM1
ERCC1
BRCA1
Biospecimen Acquisition Method of tissue acquisition Ultrasound-guided biopsy
CT-guided biopsy
Forceps
Preaquisition Patient gender Female
Male
SNP assay Specific Targeted nucleic acid EGFR