MATERIALS AND METHODS: The EGFR intron 1 polymorphism was analysed in three distinct healthy Asian subjects, namely, Chinese (N = 96), Malays (N = 98) and Indians (N = 100). Comparative genomic hybridisation was performed to investigate for changes in DNA copy number in relation to the polymorphic CA dinucleotide repeats in breast tumor tissues (N = 22).
RESULTS: The frequency of short alleles with 14 and 15 CA repeats were most common in the Asian populations and significantly higher than those reported for Caucasians. The frequency of 20 CA repeats was 5%, almost 13-fold lower than previous reports. EGFR amplifications were detected in 23% and 11% of breast tumor tissues harboring short and long CA repeats, respectively.
CONCLUSION: Our results show that the frequency of alleles encoding for short CA dinucleotide repeats is common in Asian populations. EGFR expression and amplification levels were also higher in Asian breast tumor tissues with short CA dinucleotide repeats. These findings suggest that the EGFR intron 1 polymorphism may influence response to treatment with tyrosine kinase inhibitors in breast cancer patients and further studies are warranted.
Purpose: To study EGFR alterations and expressions in a multi ethnic Malaysian TNBC patient cohort to determine the possibility of using anti-EGFR combinatorial therapy for this population.
Patients and methods: In this study, we evaluated 58 cases of Malaysian TNBC patient samples for EGFR gene copy number alteration and EGFR protein overexpression using fluorescence in-situ hybridization (FISH) and immunohistochemistry (IHC) methods, respectively.
Results: EGFR protein overexpression was observed in about 30% while 15.5% displayed high EGFR copy number including 5.17% gene amplification and over 10% high polysomy. There is a positive correlation between EGFR protein overexpression and gene copy number and over expression of EGFR is observed in ten out of the 48 low copy number cases (20.9%) without gene amplification.
Conclusion: This study provides the first glimpse of EGFR alterations and expressions in a multi ethnic Malaysian TNBC patient cohort emphasising the need for the nationwide large scale EGFR expression evaluation in Malaysia.
METHODS: OR cells were established via stepwise-dose escalation and limiting single-cell dilution method. We then evaluated Osimertinib resistance potential via cell viability assay. Proteins expression related to EGFR-signalling, epithelial to mesenchymal transition (EMT), and autophagy were analyzed via western blot.
RESULTS: OR cell lines exhibited increased drug resistance potential compared to H1975. Distinguishable mesenchymal-like features were observed in OR cells. Protein expression analysis revealed EGFR-independent signaling involved in the derived OR cells as well as EMT and autophagy activity.
CONCLUSION: We generated OR cell lines in-vitro as evidenced by increased drug resistance potential, increased mesenchymal features, and enhanced autophagy activity. Development of Osimertinib resistance cells may serve as in-vitro model facilitating discovery of molecular aberration present during acquired mechanism of resistance.
METHODS: ALK gene rearrangement was detected by immunostaining of ALK protein and fluorescence in situ hybridisation (FISH) targeting at the 2p23 region.
RESULTS: The expression of ALK protein was detected in 24/34 (71%) of the cases, and it was significantly higher in childhood cases (100%) when compared to adult cases (47%). The analyses by FISH were consistent with the results from immunostaining of ALK protein, but the analyses were only successful in 15/34 (44%) cases. FISH analyses detected extra copies of ALK gene in three cases, including one case that expressed ALK protein and showed 2p23 rearrangement.
CONCLUSIONS: The current series revealed a high frequency of ALK gene rearrangement, especially in the children. Immunostaining of ALK protein is a reliable indication of ALK gene rearrangement, and is superior to FISH. However, FISH analysis is useful in detecting other genetic aberrations that are not related to ALK gene rearrangement.
METHODS: In this double-blind, phase 3 trial, we randomly assigned 556 patients with previously untreated, EGFR mutation-positive (exon 19 deletion or L858R) advanced NSCLC in a 1:1 ratio to receive either osimertinib (at a dose of 80 mg once daily) or a standard EGFR-TKI (gefitinib at a dose of 250 mg once daily or erlotinib at a dose of 150 mg once daily). The primary end point was investigator-assessed progression-free survival.
RESULTS: The median progression-free survival was significantly longer with osimertinib than with standard EGFR-TKIs (18.9 months vs. 10.2 months; hazard ratio for disease progression or death, 0.46; 95% confidence interval [CI], 0.37 to 0.57; P<0.001). The objective response rate was similar in the two groups: 80% with osimertinib and 76% with standard EGFR-TKIs (odds ratio, 1.27; 95% CI, 0.85 to 1.90; P=0.24). The median duration of response was 17.2 months (95% CI, 13.8 to 22.0) with osimertinib versus 8.5 months (95% CI, 7.3 to 9.8) with standard EGFR-TKIs. Data on overall survival were immature at the interim analysis (25% maturity). The survival rate at 18 months was 83% (95% CI, 78 to 87) with osimertinib and 71% (95% CI, 65 to 76) with standard EGFR-TKIs (hazard ratio for death, 0.63; 95% CI, 0.45 to 0.88; P=0.007 [nonsignificant in the interim analysis]). Adverse events of grade 3 or higher were less frequent with osimertinib than with standard EGFR-TKIs (34% vs. 45%).
CONCLUSIONS: Osimertinib showed efficacy superior to that of standard EGFR-TKIs in the first-line treatment of EGFR mutation-positive advanced NSCLC, with a similar safety profile and lower rates of serious adverse events. (Funded by AstraZeneca; FLAURA ClinicalTrials.gov number, NCT02296125 .).
PATIENTS AND METHODS: A retrospective study was conducted based on incident lung cancer cases diagnosed between 2017 and 2019 in Lampang (Thailand), Penang (Malaysia), Singapore and Yogyakarta (Indonesia). Cases (n = 3413) were defined using the International Classification of Diseases for Oncology third edition. In Singapore, a clinical series obtained from the National Cancer Centre was used to identify patients, while corresponding population-based cancer registries were used elsewhere. Tumor and clinical information were abstracted by chart review according to a predefined study protocol. Molecular testing of epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK) gene rearrangement, ROS1 gene rearrangement and BRAF V600 mutation was recorded.
RESULTS: Among 2962 cases with a specified pathological diagnosis (86.8%), most patients had non-squamous NSCLC (75.8%). For cases with staging information (92.1%), the majority presented with metastatic disease (71.3%). Overall, molecular testing rates in the 1528 patients with stage IV non-squamous NSCLC were 67.0% for EGFR, 42.3% for ALK, 39.1% for ROS1, 7.8% for BRAF and 36.1% for PD-L1. Among these patients, first-line systemic treatment included chemotherapy (25.9%), targeted therapy (35.6%) and immunotherapy (5.9%), with 31% of patients having no record of antitumor treatment. Molecular testing and the proportion of patients receiving treatment were highly heterogenous between the regions.
CONCLUSIONS: This first analysis of data from a clinically annotated registry for lung cancer from four settings in Southeast Asia has demonstrated the feasibility of integrating clinical data within population-based cancer registries. Our study results identify areas where further development could improve patient access to optimal treatment.