Myelomonoblastic leukemia, how does it develop, what are the symptoms and signs, what is the difference from monoblastic leukemia?

What is chronic myeloid leukemia and how does it develop?

Oncological damage to myeloid hematopoietic cells, the precursors of granular leukocytes, which is chronic, in most cases (95 out of 100) is associated with the appearance of an abnormal chromosome in them, which, according to the place of discovery, was called the Philadelphia chromosome.

The occurrence of this type of mutation occurs as follows:

• due to the influence of certain negative factors on the human body, a fusion of the abl genes from the 9th chromosome and bcr from the 22nd occurs;
• a pathological compound provokes the formation of an abnormal ABL-BCR protein, which activates the process of malignancy of blood cells;
• the blast cell, the future myeloid granular leukocyte, mutated due to a chromosomal disorder, stops in its development and begins to actively divide, forming a tumor structure in the bone marrow;
• clones of abnormal blood cells enter the bloodstream, where they also actively grow, displacing healthy platelets, leukocytes and red blood cells, thereby completely disrupting the functioning of the circulatory system.

The occurrence of such a violation in the DNA of leukocytes and an uncontrolled increase in abnormal cells in the blood leads to the development of cancer in the circulatory system. But it is almost never possible to identify chronic myeloid leukemia in the incipient phase, since this pathological condition is not accompanied for a long time by specific symptoms that can cause anxiety in a person.

Acute myeloid leukemia

Acute myeloid leukemia

– a malignant disease of the blood system, accompanied by the uncontrolled proliferation of altered leukocytes, a decrease in the number of red blood cells, platelets and normal leukocytes. It manifests itself as an increased tendency to develop infections, fever, fatigue, weight loss, anemia, bleeding, the formation of petechiae and hematomas, pain in bones and joints. Sometimes skin changes and swelling of the gums are detected. The diagnosis is made based on clinical symptoms and laboratory data. Treatment is chemotherapy, bone marrow transplantation.

Chronic myeloid leukemia in children

This type of cancer is not typical for young patients; the diagnosis rate is only 1-5% of clinical cases of all childhood leukemia.

This pathological condition can occur in a small child in one of two types:

1. Juvenile (related to adolescence) chronic myeloid leukemia. This type of disease is considered “adult” and predominates in children after 5 years of age. A characteristic feature of this type of disease is the presence of the Philadelphia chromosome in the structure of leukocytes.
2. Infantile (underdeveloped, childhood) myeloid leukemia. This type of disease mainly affects children under two years of age and differs from the juvenile form in the absence of an abnormal chromosome in the blast cells. Another characteristic feature of this type of disease is a pronounced decrease in the number of leukocytes in the blood in sick children already at an early stage of the development of the pathological condition, which leads to frequent bleeding, which is very difficult to stop.

Worth knowing! The younger the child, the more acute the disease. Most often, the childhood form of myeloid leukemia is incurable - the baby’s death occurs very quickly due to the early development of thrombocytopenia, leading to extensive internal bleeding, which is often impossible to stop.

Diagnosis of the disease

Chronic myeloid leukemia is diagnosed based on the results of laboratory tests along with the characteristics of the general clinical picture of the disease. The following methods will be relevant:

• Blood test. Allows you to identify blood parameters and their ratio. As the disease develops, there is an increase in white blood cells, which are in an immature form. As the pathological process worsens, the levels of platelets and red blood cells decrease.
• Biochemical study of blood parameters. The technique allows you to determine disturbances in the functioning of the spleen and liver, which begin due to the penetration of immature leukocytes.
• Cytogenetic analysis, which involves performing a study of chromosomes. If the disease begins to develop, the leukemia cells contain an abnormal chromosome called the Philadelphia chromosome, which is distinguished by a truncated appearance.
• Bone marrow aspiration and biopsy. Research allows you to obtain maximum information. Ideally, they are performed immediately, taking material for research from the posterior region of the femur.
• Hybridization aimed at identifying abnormal chromosomes.
• MRI and CT.
• Ultrasonography.

The primary signs of chronic myeloid leukemia are determined through a blood test, when a high level of granulocytes is traced in it. This requires additional research and differentiated diagnostics. There is a need for histological examination.

The diagnosis is confirmed or refuted by the results of a cytogenetic study or PCR, through which the presence of the Philadelphia chromosome is determined.

Classification of chronic myeloid leukemia

Chronic myeloid leukemia in clinical practice is usually divided into stages depending on how mature the blood cells that make up the tumor structures are.

The development of chronic myeloid leukemia goes through 3 phases, each of which is characterized by certain clinical signs and morphological changes in the blood:

1. The chronic phase or the onset of a pathological process. Chronic myeloid leukemia begins to develop gradually. First of all, myeloid proliferation occurs (proliferation of bone marrow tissue due to activation of blast cell division), which leads to the appearance of specific changes in the blood. There are no general clinical signs at this stage, so chronic myeloid leukemia at the beginning of its development is usually an incidental finding.
2. Acceleration phase, or transition. At this stage, clinical symptoms are mild and the patient’s condition can be considered stable. Only histological signs undergo changes - the quantitative composition of leukocytes and myelocytes begins to increase.
3. Terminal, final phase. The final stage of the disease is characterized by the appearance of pronounced clinical signs that are difficult to tolerate by patients. Their appearance indicates the onset of a blast crisis. One of the features of the disease, which is always accompanied by the final phase, is an infarction of the spleen and its obvious increase due to the accumulation of a large number of blast cells in the hematopoietic organ. In more than half of patients at this phase of the disease, fibrosis (tissue enlargement) of the bone marrow is detected.

Worth knowing! It is usually possible to detect chronic myeloid leukemia of the bone marrow, spleen and blood in the last phase of the disease, which is due to the absence of specific symptoms at stages 1 and 2. Such insidiousness of the disease leads to frequent deaths, but its slow development, which can last for many years, brightens up this picture, since in many patients it is possible to identify the pathological condition in the early phase, when diagnosing another disease.

Treatment and prognosis

AML is an age-related disease. It is rare in children. The main risk of developing primary leukemia occurs after 65 years of age. The prognosis for young patients is better, as they are able to tolerate the most aggressive treatment and higher doses of chemotherapy.

In general, if you contact specialists in a timely manner, the prognosis is optimistic for most types. But this can only be determined after testing. All subtypes of myeloid leukemia respond individually to treatment. In general terms, we can say that therapy lasts about 1.5 years. Much depends on the number of diseased cells and how much they have penetrated into other organs. Another important indicator is the age of the patient. But only a correctly diagnosed type of disease and examination of the chromosomes themselves will determine the likelihood of relapse and the duration of remission.

2 stages of AML treatment

The chemotherapy itself is also called induction. It is carried out in a hospital setting. The drugs used during this procedure are called cytostatic. For example, Cytarabine is a medicine from the group of antimetabolites. The essence of chemotherapy is to block the growth and division of body cells. An anthracycline antibiotic is used at the same time. As a rule, such therapy is carried out over 7 days, and an additional antibiotic is administered in the first three days. This allows you to achieve remission (reduction in the number of diseased cells) in 70 - 80% of cases. When the patient enters a state of remission, consolidation treatment is performed.

After a course of chemotherapy, cancer cells become invisible during diagnosis, but they remain in the body, and eventually almost all patients experience a relapse. To prevent this from happening, additional therapy is carried out.

Different types of myeloid leukemia have different prognosis for relapse. Doctors look at the morphological and cytogenetic indicators of altered chromosomes. Since certain types are more prone to relapse, patients are prescribed more intensive courses.

Regarding the prognosis for older people, it is noted that 30–40% relapse after consolidation treatment. In young people under 65 years of age, relapse occurs in 10–15% of cases. This is most often due to the fact that young people tolerate treatment better. It is important to understand that statistics are taken among all cases at all ages.

Bone marrow transplant and relapse

If after consolidation treatment a relapse does occur, then a bone marrow stem cell transplant from a living donor is prescribed. Most often this is a relative of the patient. With this treatment there is a risk that his stem cells will be rejected. After this, courses of intensive chemotherapy are carried out. If necessary, in order to prevent neuroleukemia, CNS irradiation can be used.

The prognosis for relapse after stem cell transplant increases to 40%.

The outcome of treatment is also affected by the time between relapses; doctors talk about unfavorable prognoses if the time between them is less than one year.

In general, we can say that acute myeloblastic leukemia is a curable disease, you will definitely cope, good luck.

Reasons that provoke the development of blood pathologies

Chronic myeloid leukemia is the first and only cancer whose cause has been reliably established. The main prerequisite that provokes the onset of the disease is the appearance of an abnormal chromosome in the blast cells of the hematopoietic organs. The disease that arises as a result of such a genetic mutation develops very slowly, and a person can live into old age without learning about the presence of oncological pathology in his blood. But the development of chronic myeloid leukemia can also be rapid.

The disease can quickly, within a few months, reach its final phase if there are certain risk factors in a person’s life, the main ones of which are considered to be:

• living in areas with increased background radiation or areas in close proximity to nuclear power plants;
• long-term treatment with cytostatics or uncontrolled use of antibacterial drugs that have increased toxicity;
• regular, long-term exposure to toxic and chemical substances on the human body;
• a person's history of Klinefelter or Down syndrome.

If at least one of these risk factors is present in a person’s life, he needs to be more attentive to his well-being and, if minimal health problems appear, consult a specialist for advice. Also, annual preventive diagnostics are recommended for people at risk. Timely detection of pathological changes in blood composition allows the developing chronic form of myeloid leukemia to be completely cured.

Causes of the disease

In the vast majority of cases, chronic myeloid leukemia is caused by a gene mutation – a chromosomal translocation, which is commonly called the “Philadelphia chromosome”.

Technically, the process can be described as follows: chromosome 22 loses one of the fragments, which fuses with chromosome 9. A fragment of chromosome 9 attaches to chromosome 22. This causes a malfunction of genes, and then the immune system.

Experts say that the occurrence of this type of leukemia is also influenced by:

• exposure to radiation. After the nuclear attack on Hiroshima and Nagasaki, the incidence of CML in residents of Japanese cities increased significantly;
• exposure to certain chemicals - alkenes, alcohols, aldehydes. Smoking has a negative effect on the condition of patients;
• taking certain medications - cytostatics, if cancer patients take them along with undergoing radiation therapy;
• radiotherapy;
• hereditary genetic diseases - Klinefelter syndrome, Down syndrome;
• diseases of viral origin.

Important! CML mainly affects people over 30-40 years of age, and their risk of developing the disease increases with age, up to 80 years of age. It is diagnosed very rarely in children.

There is, on average, one to one and a half cases of this disease per 100 thousand inhabitants of the Earth. In children, this figure is 0.1-0.5 cases per 100 thousand people.

Symptoms of oncopathology of the hematopoietic organs

Signs of the disease are absent for a long time; the first specific symptoms of chronic myeloid leukemia, causing a person to become alarmed and visit a doctor, usually appear in the terminal stage of the disease, when it is impossible to cure it. The initial phase of the disease is characterized by vague, mild symptoms. But knowing them, you can suspect the development of a pathological condition and, by contacting a hemato-oncologist in a timely manner, diagnose chronic myeloid leukemia in an early phase that responds well to therapy.

The main signs that should raise alarm include:

• swollen lymph nodes;
• anemia, characterized by pale skin;
• constant feeling of malaise and fatigue;
• unreasonable loss of appetite and weight loss;
• the appearance of bruises and bruises on the skin;
• frequent and prolonged external or internal bleeding;
• feeling of fullness on the left side of the abdominal cavity due to an increase in the size of the spleen.

These symptoms are typical for many diseases, but their appearance cannot be ignored, because they may indirectly indicate a developing blood cancer. Often it is thanks to the patient’s complaints about the presence of these signs that a dangerous disease can be detected in a timely manner.

Types of therapy for chronic myeloid leukemia: medication, surgery, radiation

All therapeutic measures used to stop the oncological process that has affected the hematopoietic organs are prescribed by a hemato-oncologist based on the phase of development of the disease, general signs characterizing its course and the severity of the clinical picture accompanying chronic myeloid leukemia.

Therapeutic measures are prescribed individually to each patient, depending on the stage of the disease:

1. In the initial, chronic phase, no special treatment is required. To maintain a stable condition in patients, they are prescribed general restorative therapy, which consists of correcting nutrition, reducing physical activity and observing a work-rest regime.
2. The activation phase of chronic myeloid leukemia requires expansion of therapeutic measures. Patients are required to undergo courses of biological therapy with Interferon and chemistry with Chloroethylaminouracil, Hexaphosphamide or Mitobronitol. If indicated, a bone marrow transplant may be prescribed.
3. When a blast crisis occurs, treatment becomes useless. At this final phase of the disease, patients receive exclusively symptomatic therapy to alleviate the painful symptoms of the disease and maintain quality of life until the last days.

Prognosis for recovery

It is possible to stop developing chronic myeloid leukemia only at the initial stage of the pathological process, provided that the treatment is carried out correctly. But this happens very rarely, since timely detection of the disease presents serious difficulties. Most patients die in the transition or terminal phase of chronic myeloid leukemia. From diagnosis of the disease to death at these stages of the disease, it takes about two years. Of particular danger is the onset of blast crisis - during this phase, cancer patients live no longer than six months. The most unfavorable is the presence of an abnormal Philadelphia chromosome in the blood genes.

Prevention of myeloid leukemia

There are currently no specific preventive measures to prevent chronic myeloid leukemia. The only thing hemato-oncologists advise people who are at risk for developing an oncological process in the hematopoietic organs is regular screening tests.

General recommendations for the prevention of chronic myeloid leukemia include:

• correction of the diet with the inclusion in the daily menu of dishes enriched with vitamin and mineral complexes;
• complete cessation of addictions (smoking, alcohol abuse, evening overeating), or reducing them to a minimum;
• maintaining an active, healthy lifestyle with regular participation in feasible sports;
• Reducing exposure to ultraviolet radiation: avoiding exposure to direct sunlight.