Abstract
Objective: Pulmonary mycobacterium avium complex (MAC) disease is increasing significantly worldwide. Several studies have investigated the clinical features of pulmonary MAC disease in the setting of cancer. Here, we aimed to clarify the clinical characteristics of patients with cancer with recent onset of pulmonary MAC disease and the effect of cancer on the onset of this disease. Patients and Methods: Of the 323 consecutive Japanese patients newly diagnosed with pulmonary MAC disease at Jichi Medical University Hospital between and 2006-2017, we retrospectively reviewed 79 consecutive patients with cancer. Results: Seventeen patients had lung cancer (21.0%), while 62 had non-lung cancer. Of the 17 patients with lung cancer, 16 had adenocarcinoma of which 10 had stage I to III disease; 8 of the 10 patients had not received chemotherapy. Sixteen patients with lung cancer had a MAC infection in the ipsilateral lung. Notably, 9 of the 11 lung cancer patients who did not undergo surgery had a MAC infection in the affected lobe. Of the 39 patients with the most common types of non-lung cancer (14 had gastric cancer, 13 had colorectal cancer, and 12 had breast cancer), 22 had stage I to III disease, and 18 of these 22 had not received chemotherapy. Conclusion: Lung cancer may act as a local factor contributing to the onset of pulmonary MAC disease in the ipsilateral lung. However, the underlying mechanism by which a history of cancer might affect the onset of pulmonary MAC disease remains unclear. Further investigation into this mechanism is needed.