Anti-cancer therapy and the exacerbation of pulmonary nontuberculous mycobacterial infection

Immunosuppressive cytotoxic chemotherapy for malignant tumors may activate underlying nontuberculous mycobacteria (NTM) infections. However, chemotherapy-induced NTM pulmonary disease exacerbations have not been systematically evaluated. Thus, in this novel study, we aimed to evaluate the effects of chemotherapies on patients with concomitant NTM pulmonary diseases and malignant tumors. In this single-center study, we retrospectively reviewed medical records of patients with histopathologically proven malignant tumors and concurrent NTM pulmonary disease between September 2012 and September 2022. Data, including clinical history, imaging, tumor type, NTM etiological data, and treatment course, were collected. Of the 193 patients diagnosed with NTM pulmonary diseases, 54 (28%) had concurrent malignant tumors. Eighteen of these patients received at least one chemotherapeutic agent, and two (11%) developed NTM pulmonary disease exacerbations. One patient with early-stage breast cancer developed an NTM pulmonary disease exacerbation after receiving two cycles of adjuvant paclitaxel therapy. Another patient with malignant lymphoma developed an NTM pulmonary disease exacerbation 81 months after receiving rituximab-containing chemotherapy. Both patients responded to anti-NTM therapy. The patient with malignant lymphoma received ethambutol and clarithromycin during chemotherapy. Despite the small sample size, this hypothesis-generating study suggests that chemotherapy may exacerbate NTM pulmonary disease. As the first to investigate this interaction in patients with both conditions, the findings highlight the need for large prospective studies.