[Clinical characteristics of pulmonary Mycobacterium avium complex infection complicated with lung cancer].

Objectives: The coexistence of lung cancer and pulmonary Mycobacterium avium complex (MAC) infection has not been well reported. This study illustrated the clinical characteristics of pulmonary MAC infections complicated with lung cancer.

Patients and methods: We conducted a retrospective analysis of the clinical characteristics of patients with pulmonary MAC infections complicated with newly diagnosed lung cancer between 2006 and 2012.

Results: Of 530 patients with pulmonary MAC infections, 13 (2.4%) were complicated with lung cancer. Six men and 7 women with a mean age of 73 years were also diagnosed with cancer, and 5 had a smoking history. Six patients were diagnosed concurrently, and 7 patients were diagnosed with pulmonary MAC infections prior to being diagnosed with cancer. Histological examination revealed adenocarcinoma, small cell carcinoma, and other cancer types in 9, 2, and 2 patients, respectively. Eleven of 13 patients had cancers of stages I-IIIA, and 10 underwent cancer resection. Analysis of the anatomical relationship between lung cancer and MAC revealed that both diseases were present in the same lobe in 10 patients. The disease extent was within one-third of a single lung field in 9 patients. Anti-MAC treatment was initiated in 7 patients, but was discontinued in 2 patients owing to side effects. Six patients did not receive anti-MAC treatment.

Conclusion: In this study, lung cancer was frequent among patients with pulmonary MAC infections, and both diseases tended to be in the early stages. Physicians should consider coexisting lung cancer when managing MAC infections.