Rapidly growing mycobacteria infection in patients with cancer.

BACKGROUND: Rapidly growing mycobacteria (RGM) have been associated with various clinical syndromes in immunocompetent and immunocompromised hosts. The risk factors and outcomes of RGM infection in patients with cancer have not been clearly defined.

METHODS: Data were derived from 2 distinct sources. Demographic and clinical data were collected for all patients with cancer at Memorial Sloan-Kettering Cancer Center with a culture positive for RGM from January 1999 through December 2008. We also reviewed the literature for studies describing RGM infection in patients with cancer.

RESULTS: During the 10-year period, 28 patients with cancer at Memorial Sloan-Kettering Cancer Center had cultures positive for RGM. Most cases occurred in patients with solid tumors and were confined to the lung. A review of the literature identified 313 additional patients with cancer and RGM infection. Combining our series data with cases from the literature, we defined 3 distinct syndromes: pulmonary disease, which occurred in 158 patients (47%); bloodstream infection, occurring in 151 patients (45%); and disseminated infection involving at least 1 end organ, affecting 26 persons (8%). The syndromes differed by age of onset, underlying cancer, main RGM species, and outcome. Persons with bloodstream infection typically were young and had an excellent outcome; those with disseminated infection were older, had pronounced immunosuppression, and had a very poor prognosis.

CONCLUSIONS: RGM infections in patients with cancer comprise 3 distinct disorders with different risk factors, predominant mycobacterial species, and prognoses. In turn, the approach to management, including number and duration of antimycobacterial drugs, may be fundamentally different for various patients with cancer who receive a diagnosis of RGM infection.