Once poorly understood, systemic mastocytosis (SM) is now recognized as a type of blood cancer driven by a single change in a gene called KIT D816V. This discovery has reshaped how doctors find and treat the disease, according to a recent review published in Cancers.
New guidance issued in 2022 by the World Health Organization (WHO) helps doctors combine several kinds of tests — looking at cells under a microscope, running blood tests and studying genes — to make a clear diagnosis and sort patients into milder and more serious groups.
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Treatments have also improved. In the past, doctors mainly used drugs that attacked many cells at once. These drugs often only worked in the short-term, and caused significant side effects. Now SM can be treated with newer, very targeted drugs, like avapritinib, bezuclastinib and elenestinib. These can control the disease better and for longer, often with fewer or milder side effects.
But there are still challenges, the authors noted. Some patients are diagnosed late, or not at all, especially if they do not fit the “usual” picture — for example, if their tryptaseTryptase A protein enzyme that is primarily produced by mast cells and stored in small pockets within the cells, known as granules. High levels of tryptase are a key indicator of SM. level is normal, their lab tests look unusual or they also have a condition called hereditary alpha‑tryptasemia. We also don’t yet have direct “head‑to‑head” studies comparing the newer KIT‑blocking drugs with each other. And we still don’t fully understand how extra gene changes might cause the disease to become resistant to these drugs over time.
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To solve these problems, different specialists — blood doctors (hematologists), allergy doctors (allergists), skin doctors (dermatologists) and lab/pathology doctors — need to keep working closely together, the review’s authors said.
“The essential takeaway,” they said, “is that systemic mastocytosisMastocytosis Rare disease caused by the buildup of mast cells. Cutaneous mastocytosis primarily affects the skin and is more common in children, while systemic mastocytosis affects internal organs and is more common in adults. is now a treatable, molecularly targetable disease, and that early recognition, accurate subclassification, and timely referral are what translate this scientific progress into better outcomes for patients.”
