What is Myelofibrosis
Myelofibrosis is a type of blood cancer that belongs to the group of chronic myeloproliferative disorders. In this condition, fibrous tissue in the bone marrow replaces blood-producing cells, resulting in the production of red blood cells with abnormal shapes, as well as anemia and an enlarged spleen. It is a rare disease.
In a normal and healthy bone marrow, cells called fibroblasts produce the fibrous tissue that supports blood-producing cells. When myelofibrosis occurs, this production is excessive and displaces blood-producing cells, with some of them migrating from the bone marrow to the spleen and liver.
The production of red blood cells decreases, and the patient develops anemia. Many of these red blood cells are immature or deformed, and variable amounts of platelets (which usually decrease) and immature white blood cells (which may increase or decrease) are also observed in the blood.
It is a disease that affects men and women equally and is more common in people over 50 years old, with an average age of 65 to 67 years at diagnosis. However, it can occur at any age, ranging from newborns to individuals in their 90s.
Subtypes of myelofibrosis
Myelofibrosis is classified into two types:
- Primary myelofibrosis – is myelofibrosis that develops on its own, without a determined or known cause. It predominantly occurs in men between 50 and 70 years of age.
About half of people with primary myelofibrosis have a mutation in the JAK2 gene, which controls enzymes involved in cell growth and immune response, while others have a mutation in the CALR gene, related to the production of proteins necessary for proper cell function, or in the MPL gene, a thrombopoietin receptor.
But these mutations cannot be defined as the cause of the disease, as many patients do not have any of the three and they are not exclusive to myelofibrosis.
But these mutations cannot be defined as the cause of the disease, as many patients do not have any of the three and they are not exclusive to myelofibrosis;
- Secondary myelofibrosis – is myelofibrosis resulting from the progression of other diseases or disorders, especially those of the blood (hematologic), malignant or non-malignant. Among these diseases and disorders are chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, multiple myeloma, Hodgkin’s lymphoma and non-Hodgkin’s lymphoma, cancer with metastasis in the bone marrow, and myelodysplasia.
It can also occur in people with tuberculosis, pulmonary hypertension, lupus, systemic sclerosis, and HIV infection.
In both cases, there is a risk of the disease progressing to acute myeloid leukemia or to problems such as bleeding in the digestive system and the development of thromboembolic events.
Symptoms and signs of myelofibrosis
Many myelofibrosis patients are asymptomatic or take many years to develop symptoms. When signs of the disease appear, early or late, the most common ones are:
- Excessive and progressive fatigue without apparent cause;
- Weakness;
- Shortness of breath;
- Difficulty breathing;
- Discomfort on the left side of the abdomen, caused by spleen swelling;
- Appearance of bruises on the skin;
- Night sweats;
- Fevers;
- Frequent infections, caused by decreased immunity;
- Unexplained weight loss;
- Bone and joint pain;
- Anemia;
- Paleness;
- Bleeding;
- Thrombosis;
- General malaise.
Diagnosis of myelofibrosis
When suspecting the occurrence of myelofibrosis cancer due to a set of symptoms, the specialist doctor requests a complete blood count to begin the investigation. It is possible to detect problems in the cell count, as well as anemia and deformed and/or immature red blood cells, which indicate the disease.
If there are alterations, a bone marrow biopsy is then performed. In this procedure, a small fragment of the hip bone is removed with a needle and examined. A genetic mutation test may also be requested, searching for JAK2, CALR, or MPL mutant genes.
Based on the biopsy result, the diagnosis can be confirmed. Genetic tests are performed to detail the characteristics of the disease, which is useful in defining the treatment.
Myelofibrosis treatment
The only treatment capable of definitively curing myelofibrosis is a bone marrow transplant, but it should only be considered if the patient is up to 65 years old, does not have other significant health problems, and has a chance of survival of more than five years.
Other possible treatments aim to control the disease and prevent the condition from worsening, as well as alleviate the discomfort caused by symptoms. Medications are used to reduce the size of the spleen, normalize platelet count, and improve anemia.
In rare cases, it may be necessary to remove the spleen, which is only indicated if all other measures have already been attempted.
Prevention for myelofibrosis
Since primary myelofibrosis has no defined cause and secondary myelofibrosis is a consequence of the progression of other diseases and disorders, there is no known way to prevent them.
