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A.R.H. Utomo
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P3.01 - Advanced NSCLC (ID 621)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Advanced NSCLC
- Presentations: 2
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.01-053 - Detection of Common EGFR Mutation in Cytological Smears Using Reversed Dot Blot (RDB) Hybridization Method (ID 9765)
09:30 - 09:30 | Author(s): A.R.H. Utomo
- Abstract
Background:
Epidermal growth factor receptor (EGFR) mutation can predict the response to EGFR tyrosine kinase inhibitor (TKI) in non small cell lung cancer (NSCLC). In this study, we determined the limit of detection of different methods, such as sequencing, restriction frament length polymorphism (RFLP), high resolution melting (HRM) and reversed dot blot (RDB) hybridization to detect for EGFR mutation detection.
Method:
Mutation detections of exons19 and 21 in EGFR gene were performed using sequencing, restriction fragment length polymorphism (RFLP) and high resolution melting (HRM) analysis method. Moreover, we also developed Reversed Dot Blot(RDB) method hybridization as an alternative procedure. Genomic DNA of H1975, HCT116 cell line as well as specially designed oligonucleotides were used to determine the limit of detection of these procedures. We also determine the sensitivity and specificity of RDB method compared to existing methods.
Result:
Limit of detection of each method was determined by titration of mutant allele in wildtype background. HRM analysis and RFLP were able to detect mutation in samples containing 6.25% to 12.5% mutated DNA.Limit of detection of RDB method was around 12.5%. Analysis of 40 patients had shown that the specificity for to detect mutations in exon 19 and 21 was 100% and 89.5% and the sensitivity for both exon was 62.5%.
Conclusion:
RDB method maybe used as an alternative method to standard procedure such as sequencing. This method is specific, but need further improvement to increase its sensitivity.
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P3.01-054 - Urinary ct-DNA Testing of EGFR Common Mutation in Non-Small Cell Lung Cancer Patients (ID 9780)
09:30 - 09:30 | Author(s): A.R.H. Utomo
- Abstract
Background:
The existence of circulating tumor DNA (ct-DNA) in urine as a noninvasive and alternative sample to tissue biopsy has been promising. However, it still has some challenges. Common mutations of epidermal growth factor receptor (EGFR), such as L858R in exon 21 mutation has been used to predict lung cancer treatment response to tyrosine kinase inhibitors (TKI). The study aimed to demonstrate that DNA from urine can be detected using simple methods with high sensitivity, enabling early Non-Small Cell Lung Cancer (NSCLC) detection from these noninvasive samples.
Method:
Cytological smear and urine samples from 59 NSCLC patients had been collected and processed to obtain genomic DNA. EGFR common mutations in exon 21 were analyzed using polymerase chain reactions (PCR) and restriction fragment length polymorphism (RFLP) methods that having analytical sensitivity of detecting 3% EGFR mutant alleles. Diagnostic sensitivity and specificity test was used to evaluate the feasibility of urine as source of noninvasive samples compared with cytological samples.
Result:
We were able to detect EGFR exon 21 L858R mutations in 17 of 59 (28,81%) urine samples while 27 of 59 (45,76%) cytological samples were EGFR positive mutations. Agreement between urine and cytological slide was 45.76%. Diagnostic sensitivity and specificity were 22,22% and 65.62% respectively.
Conclusion:
EGFR mutation of lung cancer patients were detected from urine using RFLP methods. In this study, mutation rate in urine (28,81%) was similar to mutation rate from plasma (22%) of Asian Lung cancer patients as described Han, B et al 2015. However, poor sensitivity (22.22%) and specificity (65.62%) of urinary ctDNA L858R analysis may not lead to treatment decision. More in-depth studies focusing on urine collection techniques and more sensitive technology may lead to useful application of urine as an alternative noninvasive liquid biopsy sample for NSCLC detection.
