Increased lung cancer risk and associated risk factors in tuberculosis survivors: A Korean population-based study.

BACKGROUND: Few studies have comprehensively evaluated the risk of lung cancer in tuberculosis (TB) survivors with consideration of smoking status and chronic obstructive pulmonary disease (COPD). Furthermore, little is known about lung cancer risk factors in TB survivors.

METHODS: This population-based cohort study enrolled TB survivors (n=75,467) between 2010 and 2017 and 1:1 age- and sex-matched controls. Subjects were followed up for one year from the date of TB diagnosis to the date of the incident lung cancer, death, or Dec, 2018, whichever came first. The risk of lung cancer was evaluated according to smoking and COPD status. Additionally, We evaluated the risk factors for lung cancer and developed an individualized lung cancer prediction model for TB survivors.

RESULTS: During a median follow-up duration of 4.8 years, the incident lung cancer risk was 1.72-fold higher in TB survivors than in the controls. Among TB survivors, those who were current smokers with ≥20 pack-years showed the highest risk of lung cancer (adjusted hazard ratio [aHR]=6.78) compared to never-smoker, non-TB controls. TB survivors with COPD had a higher risk (aHR=2.43) than non-COPD, non-TB controls. Risk factors for lung cancer in TB survivors were pulmonary TB, age>60 years, smoking, and the presence of COPD or asthma. The individualized lung cancer risk model showed good discrimination (c-statistic=0.827).

CONCLUSIONS: Previous TB infection is an independent risk factor independent of smoking status or amount and COPD. Closer monitoring of TB survivors, especially heavy smokers or those with COPD, is needed for early lung cancer diagnosis.