Supplementary Material for: Increased Risk of Tuberculosis Disease in Lung Cancer Patients Undergoing Immune Checkpoint Inhibitor Therapy: A Retrospective Multicenter Study

Introduction: The introduction of immune checkpoint inhibitor (ICI) therapy in lung cancer has improved survival rates, leading to its widespread use. However, there has been a recent increase in case reports of tuberculosis (TB) disease occurrence following ICI treatment. The objective of this study was to ascertain whether the incidence of TB disease is elevated in the ICI group compared to the group receiving platinum-based chemotherapy among all lung cancer patients. Methods: To compare the risk of TB disease occurrence between the ICI group and the Platinum group in lung cancer patients, a retrospective study was conducted using the clinical data warehouse platform of eight university hospitals affiliated with the Catholic Medical Center in South Korea. Results: Out of a total of 7,980 patients, those meeting the exclusion criteria were excluded, 991 were categorized into the ICI group, and 3,646 were classified into the Platinum group. The TB disease incidence rate was significantly higher in the ICI group (4.46 per 1,000 person-years) than in the platinum group (1.12 per 1,000 person-years), with a rate ratio (RR) of 3.98 (95% CI: 1.58–10.00; p = 0.003). Multivariable analysis confirmed ICI therapy as the sole factor significantly associated with TB disease occurrence (adjusted HR: 3.701 95% CI: 1.467-9.333; p = 0.006). Conclusion: Treatment with ICI in lung cancer patients was associated with a statistically significant increase in the risk of TB disease occurrence compared to conventional platinum-based chemotherapy. Therefore, particularly in patients treated with ICI therapy, prompt respiratory sample tests should be performed for early TB disease diagnosis when new lung lesions are identified.