[Pulmonary nontuberculous mycobacteriosis in patients with lung cancer]

To clarify the clinical features of the coexisting lung cancer and nontuberculous mycobacteriosis of the lung.

We analyzed clinical data on 11 admitted cases of coexisting lung cancer and pulmonary non-tuberculous mycobacteriosis at National Organization Tokyo Hospital during the period from 1997 to 2002.

There were 10 men and 1 woman, with a mean age of 66 years. Five of 11 patients had underlying pulmonary disorders, such as healed tuberculosis and lung cyst. Histological types of lung cancer were squamous cell carcinoma in 4, adenocarcinoma and small cell carcinoma in 3 each, and 8 out of 11 cases were in stages III to IV. We classified the 11 cases into 2 groups: (1) lung cancer concurrently detected with mycobacteriosis (8 cases) and (2) lung cancer sequentially detected during the follow-up of mycobacteriosis (3 cases). Lung cancers in the latter group were in relatively early stages and all patients of this group received resection of the cancer, while most of lung cancers in the concurrent group were in far-advanced, and palliative and/or supportive treatment for lung cancer were frequently selected. The strains of mycobacteria were as follows: M. avium complex (6 cases) and M. kansasii (5 cases). The incidence of lung cancer among patients with nontuberculous mycobacteriosis was 2.5 percent (2 percent of M. avium complex diseases patients and 8.2 percent of M. kansasii disease patients), while the incidence of nontuberculous mycobacteriosis in untreated lung cancer patients was 1.4 percent. Analysis of anatomical relationship between lung cancer and non-tuberculous mycobacteriosis revealed that the two diseases located in the same lung in 8 cases, and also in the same lobe in 4 out of the 8 cases. Outcome of treatment for nontuberculous mycobacteriosis was good especially in patients with M. kansasii disease, and it seemed that coexisting nontuberculous mycobacteriosis did not influence on the prognosis of lung cancer patients.

In the management of lung cancer, physicians should consider the possibility of coexisting pulmonary non-tuberculous mycobacteriosis, as well as coexisting pulmonary tuberculosis.