PS01.18: The Characteristics of Active Pulmonary Tuberculosis in Lung Cancer Patients: Topic: Pulmonology.

The incidence of tuberculosis is over 9 million new cases per year worldwide, with an uneven distribution. Developing countries harbor a large burden of tuberculosis. Although it is not completely understood what the underlying mechanism for this increased risk is, it has been reported that scarring of the lung after tuberculosis predisposes to the development of lung cancer, especially adenocarcinoma. And there is no definitive study about active pulmonary tuberculosis in lung cancer patients. Therefore, we conducted a cohort study to describe the clinical characteristics of patients with pulmonary tuberculosis and lung cancer. We enrolled retrospectively the patients (age ≥ 45 year-old (yr) who diagnosed to active pulmonary tuberculosis (PTB) in Yonsei University Wonju Severance hospital (an 850-bed tertiary hospital) from January 2010 to December 2014. Active PTB was defined by a positive acid-fast bacilli (AFB) smear or positive culture of Mycobacterium tuberculosis. We excluded the patients who previously (before the study period) diagnosed active PTB. We collected demographic and clinical data at the time of diagnosis of active PTB including age, gender, smoking history and amounts, initial body mass index (BMI). For lung cancer cases, additional information, including histologic type, cancer stage was collected from medical records. During study periods, a total of 418 patients were diagnosed with active PTB and 35 (8.4%) of total patients had lung cancer before being diagnosed with PTB. The median age was 60 (53 – 73) years old, and 256 (61.2%) patients were male. Two hundred twenty-five (53.8%) patients had smoking histories and median BMI (kg/m2) was 21.5 (19.8 – 23.7). Flexible bronchoscopy (FB) was performed in 356 (85.2%) of enrolled patients and TB-PCR was positive in 241 (57.7%) patients. When we compared active PTB between with lung cancer and without lung cancer, BMI was significantly lower in active PTB with lung cancer than in PTB without lung cancer (20.6 (17.6 - 22.5) kg/m2 vs. 21.5 (19.9 – 23.7) kg/m2, p = 0.049). COPD was more frequently observed in active PTB with lung cancer than in PTB without lung cancer (34.3% vs. 14.6%, p = 0.003). And the 12-month mortality was significantly higher in active PTB with lung cancer than in PTB without lung cancer (11.4% vs. 1.0%, p = 0.002). BMI was significantly lower and COPD was more frequently observed in active PTB with lung cancer. The 12-month mortality was significantly higher in active PTB with lung cancer than without lung cancer.