Low-dose computed tomography lung cancer screening in asymptomatic young adults

This study evaluated temporal trends in the age distribution of opportunistic low-dose computed tomography (LDCT) screening relative to national proportions of invasive lung cancer among adults aged 20-39 years.

Age-specific proportions of invasive lung cancer were analyzed using data from the Taiwan Cancer Registry (2011-2023) relative to total annual cancer diagnoses. Opportunistic LDCT screening-defined as voluntary screening among asymptomatic individuals outside organized national programs-was evaluated using single-center health checkup data over the same period, with annual screening totals as the denominator. Temporal trends and slope differences between screening and cancer proportions were evaluated using simple linear regression and analysis of covariance.

Between 2011 and 2023, the proportion of national invasive lung cancer remained stable among adults aged 20-29 years (0.2-0.4%; slope 0.013) and increased modestly among those aged 30-39 years (1.4% to 2.1%; slope 0.068). Conversely, within the opportunistic LDCT cohort, the proportion of examinees aged 20-29 years increased from 0.9% to 1.8% (slope 0.105), and those aged 30-39 years increased from 5.7% to 9.1% (slope 0.367). Regression analysis demonstrated that the proportional rise of young examinees in the LDCT cohort significantly exceeded the epidemiologic trend of invasive lung cancer diagnoses in both age groups and across sexes (p < 0.05 for all comparisons).

The proportional representation of adults aged 20-39 years among opportunistic LDCT examinees expanded rapidly, contrasting with the persistently low national cancer burden in this demographic. Because current evidence-based guidelines do not recommend routine LDCT screening for adults aged < 40 years, public health efforts should focus on strengthening education regarding guideline-based eligibility and prioritizing primary prevention strategies.