Patient and Advanced Practitioner Perspectives on Symptom Burden and Symptom Management in Indolent Systemic Mastocytosis

Background: Symptom burden is the primary driver for patients with indolent systemic mastocytosis (ISM) to seek medical care, whether or not they are diagnosed. Purpose: This descriptive study aimed to describe the advanced practitioner (AP) and ISM patient perspective relative to the symptom burden of ISM, multidisciplinary diagnosis and management of ISM, barriers to symptom management, strategies for collaborative management of ISM, and communicative health literacy in patients with ISM. Methods: An ISM patient survey and AP survey were developed by an AP-led steering committee incorporating validated tools to measure symptom burden, symptom burden impact, barriers, and strategies for improving symptom burden. Surveys were embedded in Qualtrics and were deployed by Conexiant to a convenience sample of AP members of the Advanced Practitioner Society for Hematology/Oncology (APSHO), AP members of the American Initiative in Mast Cell Diseases, and patients affiliated with The Mast Cell Disease Society between December 22, 2024, and February 3, 2025. Findings: 50 APs and 53 ISM patients completed 100% of the questions on the corresponding surveys. The symptom burden described using the Indolent Systemic Mastocytosis Symptom Assessment Form (ISM-SAF) to identify the symptoms that are most common, most challenging, and have the greatest impact on quality of life aligns with published data for patients in this survey. Only 24% (n = 13) of ISM patients indicated their disease was well controlled, while 76% of APs indicated greater than 50% of their ISM patients had well-controlled disease (n = 38). Most APs (68%) in the survey indicated they saw one to five ISM patients per year but were comfortable with managing ISM-related symptoms (54%, n = 27). Practice patterns for triage, multidisciplinary management, and shared decision-making are described. Conclusions: This is the first ISM symptom burden–focused survey to provide a direct comparison of patient responses to those of APs in hematology/oncology and allergy and immunology. Indolent systemic mastocytosis symptom burden measurement and symptom burden reduction remain challenging, with several barriers and gaps identified in this study. The APSHO Toolkit for Systemic Mastocytosis, developed in parallel to this study, provides an AP-focused resource for overcoming some of the barriers and gaps identified in this study.