PV QA 2 - Poster Viewing Q&A 2
MO_44_2544 - A Population-Based Study of Neoplastic Mast Cell Disease
Monday, October 22
10:45 AM - 12:15 PM
Location: Innovation Hub, Exhibit Hall 3
A Population-Based Study of Neoplastic Mast Cell Disease
J. Budnik1, and M. T. Milano2; 1Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, 2University of Rochester Medical Center, Rochester, NY
Purpose/Objective(s): Neoplastic mast cell disease (NMCD) is rare and exhibits a spectrum of severity from indolent cutaneous lesions to leukemia. To date few population-based studies have examined demographic and clinical correlates of overall survival (OS) in patients with NMCD. We aimed to investigate this using the Surveillance, Epidemiology, and End Results (SEER) database.
Materials/Methods: We included 601 patients from the SEER 18 registries diagnosed with malignant NMCD from 1975-2014. These patients were defined by the following ICD-O-3 codes: 9740/3, mast cell sarcoma (MCS); 9741/3, systemic mastocytosis (SM); and 9742/3, mast cell leukemia (MCL). Kaplan-Meier analyses, log-rank tests, and Cox proportional hazards models were used to assess the impact of demographic and clinical factors on OS.
Results: The cohort was predominantly white (n=553, 92%). Roughly half of the patients were female (n=303, 50.4%). Patient age at diagnosis ranged from 0-91 years (median 55 years). The majority of patients were coded as having SM (n=558, 92.8%). Median OS for those with SM, MCS, and MCL were 186, 133, and 14 months respectively (p<0.001 log-rank test). With Cox regression accounting for age at diagnosis, year of diagnosis, race, sex, histology, site of disease, surgery for NMCD, radiation for NMCD, and chemotherapy for NMCD, female sex was associated with an improved OS (HR=0.60, 95% CI 0.44-0.80, p<0.001). Black race was associated with poorer OS (HR=2.63, 95% CI 1.46-4.73, p<0.01). OS was comparable across different sites of disease, with the exception of worse OS with disease coded as in the lymph nodes (HR 5.41, 95% CI 1.58-18.51, p<0.01). History of surgery for NMCD (HR=3.13, 95% CI 1.52-6.42, p<0.01) and chemotherapy for NMCD (HR=3.07, 95% CI 2.33-4.22, p<0.001) were associated with poorer OS relative to those that did not receive these interventions. Radiotherapy for NMCD did not significantly affect OS (HR=0.63, 95% CI 0.24-1.47, p=0.29).
Conclusion: This hypothesis-generating population-based study suggests that NMCD has a variable prognosis—those coded as having MCS and MCL had poorer OS compared to those with SM. Prognosis is affected by sex and race. The poorer OS associated with surgery for NMCD, and chemotherapy for NMCD likely represents selection bias. Further study is needed to overcome the biases inherent in population-based retrospective analyses and better characterize NMCD prognostic factors. Prospective study is needed to develop paradigms to treat patients with NMCD optimally.
Author Disclosure: J. Budnik: Resident physician; University of Rochester. M.T. Milano: Honoraria; UpToDate.