Moreover, males are more likely to be exposed to industrial pollutants, which may also lead to the occurrence of lung cancer.11–13 Studies have shown that smoking is an independent predictor of SCLC.14,15 Thomas A et al.15 also revealed that the characteristics of non-smoking SCLC are lower tumor mutation burden, lower TP53 mutation frequency, and lack of mutation features associated with tobacco exposure. This evidence concerns the gene TP53 and small cell lung carcinoma.