J Respir Med Lung Dis | Volume 2, Issue 2 | Review Article | Open Access
Chee Shee Chai1,2, Chong Kin Liam1*, Yong Kek Pang1, Ken Siong Kow1, Chee Kuan Wong1, Mau Ern Poh1 and Jiunn Liang Tan1
1Department of Medicine, University of Malaya, Malaysia
2Department of Medicine, University Malaysia Sarawak, Malaysia
*Correspondance to: Chong Kin Liam
Fulltext PDFIntroduction: Studies of EGFR mutation frequency in patients with non-small cell lung cancer (NSCLC) or lung adenocarcinoma were limited to clinical trials, convenient sample, retrospective studies of archived samples or studies involving advanced lung cancer only.Methods: A cross sectional, single center, prospective study of EGFR mutation status among patients with newly diagnosed lung adenocarcinoma attending University Malaya Medical Center over a 4-year-period.Results: Of 394 patients with adenocarcinoma, 166 (42.1%) were tested EGFR mutation-positive while the remaining 228 (57.9%) had EGFR wild-type tumour. Exon 19 deletion mutation was the most common EGFR mutation subtype (96 (24.4%)), followed by exon 21 L858R point mutation (64 (16.2%)). On univariate analysis, gender, smoking status and smoking pack-years (p<0.001) were significantly associated with EGFR mutation status. Multivariate logistic regression analysis identified smoking status and smoking pack-year (p<0.001) as independent predictive factors for EGFR mutation positivity. EGFR mutation frequency was significantly higher in never smokers (OR, 7.12; 95% CI, 3.79 – 13.38; p<0.001) and previous smokers (OR, 2.45; 95% CI, 1.18 – 5.09; p=0.016). Compared to current or previous smokers of more than 50 pack-years, those who smoked less than 10 pack-years (OR, 7.70; 95% CI, 2.06 – 28.74; p=0.002) and 10-20 pack-years (OR, 3.42; 95% CI, 1.02 – 11.50; p=0.047) had significant higher frequency of EGFR mutation.Conclusion: EGFR mutation is common in Malaysian patients with lung adenocarcinoma. A never smoking status is a robust independent predictor of EGFR mutation positivity. EGFR mutation rate was inversely related to the amount of smoking, and is significantly lower in patients who smoked >20 pack-years.
Chai CS, Liam CK, Pang YK, Kow KS, Wong CK, Poh ME. Epidermal Growth Factor Receptor Mutation in Newly Diagnosed Lung Adenocarcinoma. J Respir Med Lung Dis. 2017; 2(2): 1016.