Systemic mastocytosis (SM) involves multiple underlying symptoms at presentation and several disease subtypes that are difficult to diagnose quickly, according to results published in the Journal of Oncology Pharmacy Practice. Tara Graff, DO, and colleagues examined clinical characteristics, treatment patterns, and the natural history associated with SM in 105 patients. SM subtypes included indolent (47.6%), aggressive (9.5%), associated with a hematological neoplasm (19.0%), mast cell leukemia (1.9%), and undocumented subtype (21.9%). Regardless of subtype, more than one-half of patients (62%) received no SM-directed active therapy, and only 26% of patients with indolent SM (ISM) underwent treatment versus 65.6% of patients with advanced subtypes. The relative risk of death in patients with advanced SM subtypes was approximately 15 times higher (HR, 15.0; 95% CI, 3.3-66.5) than in the ISM cohort.
