Age at lung cancer diagnosis in females versus males who never smoke by race and ethnicity

Background We characterized age at diagnosis and estimated sex differences for lung cancer and its histological subtypes among individuals who never smoke. Methods We analyzed the distribution of age at lung cancer diagnosis in 33,793 individuals across 8 cohort studies and two national registries from East Asia, the United States (US) and the United Kingdom (UK). Student’s t-tests were used to assess the study population differences (Δ years) in age at diagnosis comparing females and males who never smoke across subgroups defined by race/ethnicity, geographic location, and histological subtypes. Results We found that among Chinese individuals diagnosed with lung cancer who never smoke, females were diagnosed with lung cancer younger than males in the Taiwan Cancer Registry ( n = 29,832) (Δ years = −2.2 (95% confidence interval (CI):−2.5, −1.9), in Shanghai ( n = 1049) (Δ years = −1.6 (95% CI:-2.9, −0.3), and in Sutter Health and Kaiser Permanente Hawaiʽi in the US ( n = 82) (Δ years = −11.3 (95% CI: −17.7, −4.9). While there was a suggestion of similar patterns in African American and non-Hispanic White individuals. the estimated differences were not consistent across studies and were not statistically significant. Conclusions We found evidence of sex differences for age at lung cancer diagnosis among individuals who never smoke.