Clinical characteristics and survival of patients concurrently diagnosed with lung cancer and active pulmonary tuberculosis

Abstract

Background Active pulmonary tuberculosis (TB) occasionally coexists with lung cancer. However, the clinical and radiologic characteristics of this cooccurrence have not been fully evaluated. Methods Patients diagnosed with lung cancer and active pulmonary TB from January 2009 to December 2017 in four hospitals of the Catholic University of Korea were retrospectively reviewed. The clinical characteristics, including the TB diagnosis methods, lung cancer pathology, staging, initial radiographic features, and survival were analyzed and compared to 575 lung cancer patients without active pulmonary TB from the same hospitals. Results Forty-eight (0.48%) of the 9,936 lung cancer patients had active pulmonary TB confirmed by positive culture results or polymerase chain reaction analysis for M. tuberculosis at the time of the initial cancer diagnosis. The majority of the patients (95.9%) had non-small cell lung cancer and 56.2% of the lung cancers were located in the both upper lobes. In the initial computed tomography, the most frequent findings were a mass-like lesion (79.2%) and separate nodules (75%). When compared to lung cancer patients without TB, the body mass index (BMI) was lower (21.4 vs. 23.1, P = 0.001) in patients with TB. Moreover, the lung cancer patients with TB had advanced clinical stages compared to patients without TB; T3-4 (70.9% vs. 50.6%, P = 0.002), N2-3 (85.2% vs. 55.6%, P < 0.001); M1 (65.9% vs. 44.5%, P = 0.007). Patients' age, histology, location, and the presence of epidermal growth factor receptor mutations were not statistically different between the two groups. Interestingly, lung cancer with TB was associated with lower mortality (hazard ratio = 0.35, 95% CI: 0.2 1– 0.60). Conclusions Rarely diagnosed concurrent active tuberculosis in lung cancer patients was associated with lower BMI and advanced clinical stages. Active investigation of and treatment for active pulmonary TB in lung cancer patients could improve patient outcomes.