Risk Factors for Pulmonary Tuberculosis in Patients with Lung Cancer: A Retrospective Cohort Study

Background: Lung cancer increases the risk for pulmonary tuberculosis (PTB). The risk factors for newly diagnosed PTB are not known in lung cancer. This study analyzed risk factors of new-onset PTB among lung cancer patients in Taiwan. Methods: Taiwan's National Health Insurance Research Database and Taiwan Cancer Registry were used to define PTB and lung cancer patients between 2007 and 2015. Considering that mortality was a competing risk event during the cancer treatment, Fine and Gray method was performed to estimate the possible risk factors for PTB among lung cancer patients. Results: A total of 1,335 patients had PTB after lung cancer. The incidence of PTB increased with patients' raising age. Males had 1.7-fold (95% CI: 1.5-2.0) risk of PTB compared with females. Patients aged between 60-69 years (HR: 1.4; 95% CI: 1.1-1.8) and those ≥70 years (HR: 1.9; 95% CI: 1.5-2.4) had higher PTB risk than those aged under 50 years. Patients with history of pneumoconiosis and patients who received the treatments of surgery and chemotherapy also had significant increasing risk of PTB. Conclusion: Screening for PTB may be important among lung cancer patients with the aforementioned risk factors.