Clinical characteristics and risk factors for lung cancer in patients with pulmonary tuberculosis

Lung cancer (LC) and pulmonary tuberculosis (PTB) are significant respiratory diseases with major impacts on public health. LC is the foremost cause of cancer-related mortality in China, while tuberculosis (TB) is the leading cause of death from a single infectious agent worldwide. The increasing occurrence of LC-PTB comorbidities presents new challenges in clinical management. This study investigated the clinical characteristics and risk factors associated with LC-PTB comorbidity to inform future diagnostic and therapeutic strategies. This retrospective study at Guangzhou Chest Hospital reviewed 402 LC-PTB patients from October 2014 to September 2021, with clinical and epidemiological data collected and analyzed from electronic medical records. A total of 75.6% had active pulmonary tuberculosis (APTB), while 24.4% had inactive pulmonary tuberculosis (IPTB). The success rate of APTB treatment was 67.4% (205/304). In the APTB group, PTB lesions were more frequently located on the same side as LC lesions ( P  < 0.001). Additionally, the incidence of cavitary lesions was greater in the IPTB group than in the APTB group ( P  < 0.001). Based on different etiological classifications, patients with APTB were divided into bacteria-positive (B ⁺ PTB) and bacteria-negative (B ⁻ PTB) groups. In the B ⁺ PTB group, PTB lesions were more frequently located on the same side as LC lesions ( P  < 0.001), and cavitary lesions were more common ( P  < 0.001). Among the LC-B ⁻ PTB patients, PTB was detected more often before LC ( P  < 0.001), and these patients responded better to anti-TB therapy ( P  < 0.001). According to the subgroup analysis, preexisting APTB (OR = 3.79, 95% CI: 2.16–6.65, P  < 0.001) and advanced stages of LC (OR = 3.66, 95% CI: 1.53–8.79, P  = 0.004) were identified as potential risk factors for anti-TB therapy failure. LC-PTB patients have unique clinical characteristics that differ according to their activity status and pathogen classification. Preexisting APTB and advanced-stage LC may increase the risk of anti-TB therapy failure.