Nontuberculous Mycobacterial Isolates Among Cancer Patients: A Single-Center 5-Year Experience

Background Nontuberculous mycobacteria (NTM) are widely distributed in natural environments and are increasing causes of disease with significant morbidity and mortality in immunocompromised patients. We present a 5-year experience of NTM isolates at the Moffitt Cancer Center in Tampa, Fla. Methods We conducted a single-center, retrospective study of NTM isolates from January 2011 to February 2016. Records were searched to identify patients with NTM. Specimens included bronchial lavage, swabs, blood/body fluids, and tissue. Basic demographics of patients, clinical attributes, sites of isolation, and concomitant neoplasia were compared. Results There were a total of 196 isolates of NTM; 92 of 196 isolates (47%) were Mycobacterium avium complex (MAC). Mycobacterium abscessus , Mycobacterium gordonae , and Mycobacterium fortuitum accounted for 28%, 11%, and 7% of the top 4 isolates, respectively. There was no difference in types of NTM isolated based on the type of underlying neoplasm. Eleven percent of the respiratory isolates were from patients whose biopsy was negative for malignancy on workup of lung nodule. Skin/wound isolates accounted for 13%, and blood/serologic isolates accounted for 7%. Average age of patients was 68 (SD, 11) years; 92% were US born. Conclusions Nontuberculous mycobacteria isolated in our study were likely to be MAC and isolated from the respiratory tract; however, we did not find significant association between types of NTM and a given neoplasm . Mycobacterium abscessus was the next most frequent isolate from both respiratory and nonrespiratory specimens. More than 10% of isolates were from surgically excised pulmonary nodules that were benign. Improved NTM testing and scoring algorithms could reduce the need for surgical excision of pulmonary nodules.