Cumulative incidence of tuberculosis in lung cancer patients in Japan: A 6-year observational study

BackgroundTuberculosis (TB) remains a health-related problem worldwide, and certain malignancies are known to be associated with an increased risk of TB. Lung cancer is the leading cause of cancer-related death, and the number of patients with lung cancer has been reportedly increasing. As the prognosis of lung cancer remains poor, aggressive comprehensive therapies have been used. The immunosuppression caused by cancer itself and treatment-associated immune modulation may increase the risk of TB. The present study was conducted to investigate the cumulative incidence of TB in lung cancer patients.MethodsThis observational study included 904 consecutive patients diagnosed with histologically confirmed lung cancer from March 2007 to March 2013 and followed until March 2015 (mean 25.2 months). The cumulative incidence of TB was estimated using the Kaplan–Meier method.ResultsNine lung cancer patients (1.00%) developed TB during the observation period. In all cases, TB occurred within 2 years of the diagnosis of lung cancer. The cumulative incidence of TB at 6 months, 1 year, and 2 years was 0.65%, 1.15%, and 1.38%, respectively.ConclusionsThe cumulative incidence of TB in lung cancer patients was 1.38% in Japan.