A new observational study that aims to evaluate the incidence of systemic mastocytosis (SM) in patients with t(8;21) acute myeloid leukemia (AML) is now open in China.

The multicenter retrospective and prospective observational study will recruit an estimated 200 participants with newly diagnosed t(8;21) AML, aged 5 or more years.

Investigators will send a survey to all participating sites every month to collect the number of SM diagnoses associated with t(8;21) AML, t(8;21) AML without SM, and oligomastocytic SM with associated t(8;21) AML between September 2022 and August 2023. Patients will then be followed until August 2025 to have at least 2 years of observation.

The primary outcome measure of the study is the incidence of SM associated with t(8;21) AML. Secondary outcome measures include hematological characteristics, responses to the first induction therapy, the incidence of transplantation, and survival distribution of all patients with t(8;21) AML.

The estimated completion date of the trial is August 31, 2024.

t(8;21) is a translocation that occurs on the long arm of chromosome 22 in some patients with AML, causing an in-frame fusion of 2 genes, AML1 and ETO. This fusion results in the formation of a fusion protein, which has multiple effects on the proliferation, differentiation, and viability of leukemic cells.

Systemic mastocytosis is characterized by the presence of focal and/or diffuse infiltrates of neoplastic mast cells in organs such as the bone marrow, liver, spleen, and gastrointestinal tract. The exact cause of the disease is not known, but somatic mutations in the KIT proto-oncogene that result in the overproduction of mast cells are known to be involved.

Read more about the etiology of SM

In very rare cases, SM can be associated with t(8;21) AML but the exact incidence is not known.


Observational study for the evaluation of incidence of systemic mastocytosis in t(8;21) acute myeloid leukemia. ClinicalTrials.gov. August 17, 2022. Accessed September 14, 2022.