Learn The BasicsSystemic 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. (SM) is considered an incurable disease.
Prognosis is dependent on the type of disease. While those with indolent SMIndolent SM A subtype of nonadvanced SM caused by the abnormal accumulation of mast cells in the bone marrow and other organs. Indolent SM accounts for around 90% of SM cases. have a normal lifespan, patients with mast cell leukemiaMast cell leukemia The most severe subtype of SM, caused by the rapid buildup of immature mast cells in the bone marrow and blood. Mast cell leukemia accounts for less than 5% of SM cases and has a poor prognosis. have the worst prognosis.
As the disease progresses, symptoms may worsen due to the effect of mast cellMast cell A type of white blood cell produced in the bone marrow. They help defend against infections and play a key role in allergic reactions. In SM, mast cells become overactive and build up throughout the body. accumulation in the different organs and the bone marrow.
The only potential cure for SM is a bone marrow transplant, which is only recommended for patients with the aggressive form of the disease or advanced disease.
Prognosis based on disease type
There are different types of SM based on the location of the increased numbers of mast cells, symptoms that patients experience and clinical presentation and pathology findings.
Most patients have indolent SM, and the risk of the disease progressing to more severe types is low. The life expectancy of a patient with indolent SM is the same as a person without the disease.
The life expectancy of a patient with smoldering SMSmoldering SM A subtype of nonadvanced SM, with a higher mast cell burden than the indolent subtype. Smoldering SM has a higher likelihood of progressing to an advanced form. is lower than that of a patient with indolent SM. Patients with this type of disease may also be at an increased risk of their disease transforming into more advanced forms.
Patients with advanced forms of the disease such as aggressive SMAggressive SM A subtype of advanced SM marked by a high mast cell burden that leads to organ damage. Aggressive SM accounts for less than 10% of SM cases., SM with an associated hematological neoplasmSM with an associated hematological neoplasm A form of advanced SM and the second-most common subtype of SM overall. In this subtype, SM occurs alongside another blood disorder. Also called SM with an associated myeloid neoplasm. and mast cell leukemia, which is the rarest but most aggressive form of the disease, have a shortened life expectancy.
Factors affecting prognosis
A study in patients with SM seen at the Mayo Clinic between 1976 and 2007 identified the following adverse prognostic factors for survival:
- Advanced age.
- Weight loss.
- Anemia.
- Thrombocytopenia or low platelet count.
- Hypoalbuminemia or low levels of albumin
- Excess bone marrow blasts.
Survival rate of patients with SM according to disease type
According to a study published in 2019, the 10-year overall survival rate for patients with smoldering SM was 84.5%, meaning that 84.5% of patients were still alive ten years after diagnosis.
According to the same study, the 10-year overall survival rate of patients with aggressive SM was 44%. The median overall survival of these patients was 5.7 years.
According to the 2009 Mayo Clinic study, the median overall survival of patients with aggressive SM was 41 months, or 3.4 years.
According to the Mayo Clinic study, the median overall survival for patients with SM with an associated hematological neoplasm was two years while according to the 2019 study, it was 2.9 years.
The 10-year overall survival rate of patients with this type of disease was 11.2%.
Finally, the median overall survival of patients with mast cell leukemia was 1.9 years, according to the 2019 study.
Life expectancy
When considered as a whole, the life expectancy of patients with SM is shorter than healthy people of the same age and sex. The majority of deaths in patients with SM occur within the first three to five years after diagnosis.
Effect of treatment on prognosis
The development of new therapies like stem cell transplantation and immunotherapies has significantly improved the survival, prognosis and quality of life of patients with SM.
