Immune Checkpoint Inhibitors in Cancer Patients With Concurrent Active Tuberculosis: A Real-World Study in a High Tuberculosis Burden Region.

BACKGROUND: This study aimed to assess the incidence and clinical characteristics of active tuberculosis (ATB) in cancer patients treated with immune checkpoint inhibitors (ICIs) to inform optimal ICI utilization strategies in TB-endemic areas. METHODS: We conducted a retrospective analysis of 889 consecutive cancer patients who received at least one cycle of ICIs at The Third People's Hospital of Shenzhen between 01/01/2018 and 31/12/2024. Patients who developed ATB following ICI initiation were identified, and their demographic data, tumor type, ICI regimen, medical history, body mass index (BMI), and TB characteristics (time of occurrence, site) were systematically evaluated. RESULTS: Among 889 patients, the median follow-up duration was 19 months (IQR 9.7-32 months). The total follow-up time for the entire cohort was 1634.1 person-years. Forty-four patients developed ATB. The TB incidence rate was 2693 per 100 000 person-years (95% CI: 1956-3607). A total of 169 patients died during follow-up and 20 were lost to follow-up; data for both groups were censored at the last known contact date. All affected patients were male, with a median age of 61 years and a median BMI of 18.1 kg/m2. Lung cancer is an independent risk factor for ATB associated with ICIs. The median time to ATB onset after ICI initiation was 7.1 months, and patients had received a median of 5 ICI treatment cycles prior to TB diagnosis. CONCLUSIONS: This single-center retrospective cohort from a high TB-burden region demonstrated an observed TB incidence of 2693 cases per 100 000 person-years, which is higher than the general population incidence in China (55 per 100 000). While this observation cannot establish a causal relationship between ICIs and TB, it suggests that TB screening and monitoring protocols may warrant consideration in similar clinical settings. Prospective controlled studies are needed to confirm the attributable TB risk associated with ICI therapy.