High Tuberculosis Identification Among Suspected Lung Cancer Patients Using Bronchial Washing: Comparing New Rapid Molecular Test With Xpert MTB/RIF

Abstract Rationale: Tuberculosis (TB) and lung cancer are two global health problems with high mortality rates. The risk of TB increases in patients with malignancies including lung cancer with a prevalence of 0.7% – 18.7%. Pulmonary tuberculosis and lung cancer have similar symptoms so that the diagnosis of both are often late causing a worse prognosis. Bronchoscopy is an effective procedure for diagnosing TB and lung cancer. InaTB-Rif is a new rapid molecular test with shorter duration than Xpert MTB/RIF. This study aims to compare detection of tuberculosis between InaTB-Rif and Xpert MTB/RIF from bronchial washing in suspected lung cancer patients. Methods: This was a cross-sectional study with suspected lung cancer patients who would undergo bronchoscopy at Persahabatan Hospital National Respiratory Center and at least 18 years old in the period March to July 2024. We examined tuberculosis using InaTB-Rif and Xpert MTB/Rif from the same bronchial washing specimen. The result of InaTB-Rif and Xpert MTB/RIF were compared for the positivity value and kappa statistic test was applied to assess the agreement between the variables. Results: A total of 82 patients met the inclusion and exclusion criteria. 16 of 82 patients were TB based on both examinations. InaTB-Rif had substantial agreement with existing rapid molecular test, s demonstrated by the kappa statistic test (K = 0,765; p<0,001). Conclusion: InaTB-Rif is a new promising rapid molecular test to detect Mycobacterium tuberculosis. The use of bronchial washing specimens as an alternative to sputum for diagnosing tuberculosis in suspected lung cancer patients should be considered especially in high-burden TB countries such as Indonesia.