Mutational characteristics of Chinese Han and ethnic minorities in southwestern China: a propensity score matched analysis.

Background: In China, there has never been a comprehensive analysis of lung cancer-associated genetic mutations focused on ethnic minorities in the southwestern region. Our study aimed to provide valuable information on lung cancer-associated genetic alterations for cancer diagnosis and treatment, especially in ethnic minorities. Methods: Retrospective data acquisition was conducted spanning 3 years (2016.01-2019.06) among all patients who were diagnosed with lung cancer at the Third Affiliated Hospital of Kunming Medical University Hospital. A total of 5,167 patients including 373 ethnic minorities were included in this study. Propensity score matching (PSM) was used to eliminate the bias between Han and other ethnic minorities, including gender, age, smoking history, metastasis status, clinical stage, histological type, sample type, region, and Xuanwei origin. All tests were two-tailed, and significance was defined as P less than 0.05. Results: In terms of the prevalence of EGFR, EGFR L858R, EGFR T790M, ROS1, RET, MET, BRAF, and ERBB2 mutations, there was no significant difference among ethnic groups in Yunnan Province (P>0.05). A higher proportion of EGFR 19 deletion was observed in Hui patients with lung cancer compared with patients of other ethnicities in Yunnan (P=0.048). The prevalence of KRAS mutations was higher in Hani (17.65%, 3/17) and Han patients (11.44%, 80/699) than that in other Yunnan ethnicities (6.04%, 9/149; P=0.07). In Hui patients, ALK fusion was correlated with a history of non-smoking and male gender. In Bai patients, BRAF mutation was also correlated with a history of non-smoking. In all ethnic groups, EGFR mutation was more frequent in women. Conclusions: This study is the first in-depth large case-control study on genetic mutation profiles among multi-ethnic patients in southwestern China, especially focused on ethnic minorities in this area. Our study may facilitate the understanding of the etiology of this malignant disease and consequently help to reduce the incidence of lung cancer in Yunnan ethnic minority areas.