Epidermal growth factor receptor gene mutations in patients with lung adenocarcinoma differ by frequency and type between Uighur and Han ethnic groups in Xinjiang Autonomous Region

Abstract

BackgroundThis study was designed to investigate epidermal growth factor receptor (EGFR) mutation types affecting lung cancer treatment in patients in Xinjiang, China. We detected and analyzed differences in the EGFR mutation points of Uighur and Han patients with lung adenocarcinoma. We examined 181 specimens of lung adenocarcinoma tissue embedded with paraffin (76 Uighur and 105 Han patients) for mutations in the EGFR gene in exon 18-21 by the amplification refractory mutation system (ARMS) method. We used the chi-square statistical method to analyze the relationship between mutations and patients’ clinical parameters.ResultsEGFR somatic mutations were detected in 59 of 181 cases (32.6%). The mutation rate was higher in Han patients (45.7%) than in Uighur patients (15.8%) (P < 0.001). The main mutation types were the exon 19 deletion and the L858R point mutation in exon 21. In Han patients we found 21 (44.7%) cases of exon 19 deletion, 24 (51.1%) cases of L858R in exon 21, 1 case (2.1%) with mutations in both exon 19 and exon 21, and 1 case (2.1%) with T790 mutation in exon 20. In Uighur patients we found 8 (66.7%) cases of exon 19 deletion and 4 (33.3%) cases of L858R in exon 21.ConclusionsIn comparing these groups, the exon 19 deletion was more common than L858R in exon 21 in Uighur patients. In Han patients, EGFR-sensitive mutations occurred in female, never-smoking patients with well-differentiated tumors; but for Uighur patients only smoking history showed an obvious correlation.

Clinicopathologic Features and Molecular Biomarkers as Predictors of Epidermal Growth Factor Receptor Gene Mutation in Non-Small Cell Lung Cancer Patients

“…By comparing the differentiation degree of patients harboring EGFR mutation or not, well differentiated tumors in patients with EGFR mutation are more common than those in wild-type patients ( p < 0.05) [ 38 ]. As for ADC, EGFR mutation was also frequently identified in well–moderately differentiated tumors [ 15 , 39 ]. As for different mutation types, there was no statistical difference in differentiation degree between 19-Del and L858R mutations [ 11 ].…”

Social determinants of sex disparities in cancer in Southeast Asia

“…This trend shared by Asian regions, however, appears to be exclusive to patients of Asian ethnicity, because the rates of EGFR mutations in lung cancer among Caucasians were found to be lower (7–17%). 42 …”