Systemic Mastocytosis Follow-up

Updated: Jun 21, 2021
  • Author: Devapiran Jaishankar, MBBS; Chief Editor: Emmanuel C Besa, MD  more...
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The prognosis of systemic mastocytosis (systemic mast cell disease) is variable. [53] Several prognostic models for systemic mastocytosis have been developed, but there is no consensus regarding the preferred approach for defining prognosis. Young children and patients who present with primarily cutaneous and flushing manifestations tend to have little or no progression of the disease over a considerable length of time. However, older patients and those with more extensive systemic disease involving organ systems other than the skin have a poorer prognosis. [54] Although their median duration of survival is not known, it appears to be a few years.

On laboratory studies, elevated lactate dehydrogenase levels, are a poor prognostic sign. [54] On multivariate analysis, the following findings have also been shown to portend poor prognosis [9] :

  • Anemia (hemoglobin < 10.0 mg/dL)
  • Thrombocytopenia (platelet count < 150,000/μ L)
  • Hypoalbuminemia (albumin < 3.5 g/dL)
  • Excess bone marrow blasts (>5%)

In 2019, Jawhar et al published a validated five-parameter mutation-adjusted risk score (MARS) that defines three risk groups among patients with advanced systemic mastocytosis, which may improve up-front treatment stratification. [55] The MARS parameters and assigned points are as follows

  • Age > 60 years – 1 point
  • Hemoglobin < 10 g/dL) – 1 point
  • Platelet count < 100 × 10 9/L) – 1 point
  • Presence of one high molecular risk gene mutation (ie, in SRSF2, ASXL1, and/or RUNX1­ – 1 point
  • Presence of two or more high molecular risk gene mutations – 2 points

These weighted scores are used to classify patients into one of the following three risk categories:

  • Low risk: 0 to 1 point
  • Intermediate risk: 2 points
  • High risk: 3 - 5 points

Median overall survival (OS) in the three risk categories were as follows:

  • Low risk - Median OS not reached
  • Intermediate risk - Median OS 3.9 years (95% CI, 2.1 to 5.7 years)
  • High risk -  Median OS 1.9 years (95% CI, 1.3 to 2.6 years



Patient Education

Patients should carry epinephrine-filled syringes at all times and should be taught to administer epinephrine in cases of emergency.