Clinical Impact of Pulmonary Tuberculosis on the EGFR Mutational Status and Clinical Outcome in Patients with Lung Adenocarcinoma

Purpose Although it has been suggested that pulmonary tuberculosis (TB) is associated with increased risk of lung cancer, the exact mechanism is not clearly identified. We investigated the effect of pulmonary TB on the epidermal growth factor receptor (EGFR) mutational status and clinical outcome in patients with pulmonary adenocarcinoma. Materials and Methods We reviewed data of patients diagnosed with pulmonary adenocarcinoma harboring EGFR mutations and treated at our institution from 2008 to 2015. We divided our population into two groups: patients with preexisting TB lesions on chest computed tomography scan (TB group) and those without the lesions (non-TB group). We compared the differences in EGFR mutational status, response to tyrosine kinase inhibitors (TKIs) and survival between the two groups. Results A total of 477 patients with pulmonary adenocarcinoma were analyzed. One hundred eighty-three patients (39%) had EGFR-mutated tumors and 100 (21%) patients had preexisting TB lesions. The frequency of EGFR mutation was significantly higher in the TB group compared with the non-TB group (56% vs. 34%, p=0.038). Preexisting TB lesions were independently associated with more frequent EGFR mutations in multivariate analysis (odds ratio, 1.43). In addition, both the progression-free survival (9.1 months vs. 11.6 months, p=0.020) and the overall survival (19.4 months vs. 24.5 months, p=0.014) after first-line EGFR-TKIs were significantly shorter in the TB group than in the non-TB group. Conclusion Previous pulmonary TB may be associated with more frequent EGFR mutations and poorer treatment response to EGFR-TKIs in patients with pulmonary adenocarcinoma.