Leukemia is a disease related to hemoblastosis, as a result of which the cells of the bone marrow are replaced everywhere by malignant cells. In the blood of leukemia, not only tumor leukocytes appear, but also erythrocaryocytes, and megakaryocytes. In addition, the formation of blood the excess number of leukocytes in this pathology is not necessary. The malignant tumor actively grows and is practically not controlled by the body.
Leukemia is not the result of an inflammatory process or the accumulation of nonmetabolized cells. Thus, with increased production of abnormal blasts, suppression of healthy blood cells occurs, and this causes a susceptibility of the organism to infections, as well as the development of bleeding and anemia. There are two forms of malignant disease: chronic and acute, which are classified according to the type of leukocytes involved. As a rule, childhood acute lymphoblastic leukemia, and at an older age - acute form of myeloid leukemia.
Basically, leukemia is potentially curable, but in chronic form in the elderly, the predictions are not very favorable. However, the pathological course of the disease can be controlled for a long period.
Today, the reliable causes that cause the development of leukemia, are unknown. However, there are suggestions that some factors may contribute to the emergence of this pathological neoplasm in the human body. First of all, they include ionizing radiation. With its influence, cases of acute myeloblastic leukemia, which affects people of any age, and acute lymphoblastic leukemia, which is usually diagnosed in children from two to nineteen years, are becoming more frequent. Dose dependence is characterized by a high frequency of these leukemias in those who were at a distance of up to 1500 m from the epicenter itself. The frequency of acute leukemia among patients with spondylosis, which previously received radiation therapy as an analgesia, is very high. There are also numerous cases of myeloblastic and myelomonoblastic leukemia, erythromyelosis after irradiation with lymphogranulomatosis and other tumor diseases of different localization.
Also in the emergence of leukemia, a supposed role is assigned to viruses. There are such oncogenes of viral etiology that are capable of forcing the cell to continue to divide after getting into its genome. The identity of viral malignant genes with cellular was proved, and this indicates a link between leukemia and certain viruses.
Hereditary factor plays not the last role in the development of this disease. Leukemia is very often diagnosed in families where they already had a similar form of pathology. Defects are registered at the genetic level, for which changes in chromosomes are characteristic. Thus, it can be considered that leukemia develops from a single mutant cell, which begins to activate and leads to the formation of a cancer cell. After that, mutations are repeated in it, which promote the emergence of autonomous subclones, and this provokes the progression of malignant leukemia.
The symptomatology of this oncological disease consists of increasing weakness, malaise, dyspnea (in some cases), dizziness (as a consequence of anemia). With non-lymphoblastic acute leukemia, intoxication with rising temperature is noted.
Not all forms of leukemia in the extended stage occur with an increase in lymph nodes and the liver, as well as the spleen, but all this can develop at the terminal stage of leukemia regardless of the form of the disease. On the skin there are signs of hemorrhagic syndrome, which is caused by thrombocytopenia. This is manifested in the form of bleeding mucous, petechial rash, especially on the legs. Sometimes there are tumoral imperious infiltrates in the myocardium and the lungs, as well as in other systems and tissues.
In the onset of the pathological disease in the blood, characteristic cytopenia is expressed. The bone marrow is characterized by an increased number of blasts in all forms of leukopenia, in contrast to low-percentage acute pathology. With this form, less than 15% of blasts are noted, and there are more of them in the blood than in the bone marrow. The form of acute leukopenia is established on the basis of histochemical studies.
The most frequent forms in adults include myelomonoblastic leukopenia and myeloblastic.
The clinical picture of the onset of the disease is expressed in normal sizes of the main organs of hematopoiesis with non-lymph nodes. At the same time, a deep form of granulocytopenia, anemia and thrombocytopenia is noted. Often there is intoxication and a rise in temperature.
In acute promivvpotsitarnoy leukopenia, which is considered a fairly rare disease, there is a strong intoxication, hypofibrinogenemia and bleeding. Spleen, lymph nodes and liver remain normal. But in the blood, anemia is present, thrombocytopenia is strongly pronounced. The bone marrow is characterized by a large content of altered blasts. As a rule, cerebral hemorrhage leads to a lethal outcome.
Acute monoblastic leukemia is also not so common. The beginning with this form is practically, as well as with myeloblastic, but with more pronounced symptoms of intoxication and subfebrile body temperature. A common symptom of the disease is gingival hyperplasia, which is caused by tumor proliferates in them. Blood tests show a preserved germ of granulocytes, monocytes show power cells, and in the urine the amount of lysozyme reaches a high level.
Leukemia in acute plasmablastic form is characterized by the formation of blood and bone marrow of plasmocytes and plasmablasts, as well as blasts that can not be differentiated. Sometimes extramedullary foci of leukemia, such as splenomegaly, enlargement of the liver and lymph nodes, skin leukemias are noted.
In acute megakaryoblast leukemia, megakaryoblasts and undifferentiated blasts with characteristic tamocytosis are found in the blood.
For acute erythromyelosis is characterized by the progression of anemia, such as hyperchromic and normochromic. And also without reticulocytosis, blurred icterism as a result of erythrocaryocytic decay, increased thrombocytopenia and leukopenia. In the bone marrow there are erythroblasts with undifferentiated blast cells.
Very often acute leukemia is complicated by neiroleukemia. In this case, the nervous system is affected. This form of leukemia is caused by the spread of cancer cells into the brain shells or into its substance. Clinically, neiroleukemia is characterized by hypertensive and meningeal syndromes. There is persistent pain in the head, repeated vomiting, irritability, lethargy, swelling of the optic nerves, strabismus, meningeal signs and nystagmus . When studying the fluid from the spinal canal, high indices of imperious cytosis are found. With metastases inside the brain - the clinical picture is presented without cytosis.
Among chronic leukemias, frequently occurring forms are distinguished, such as erythremia, lymphocytic leukemia , myeloma, myeloleukemia, and also less often Waldenstrom's macroglobulinemia, myelofibrosis, osteomyelosclerosis and chronic monocytic leukemia.
Clinically, chronic leukemia proceeds in several stages, among which a special role belongs to such as the unfolded and terminal stages.
For the advanced stage of leukemia, there is a lack of complaints from patients, the spleen is in normal size and the blood composition is not changed. Diagnosis of leukemia at this stage on the basis of neutrophilic leukocytosis, a significant increase in leukocytes over red blood cells in the bone marrow. The unfolded stage can last up to four years. With the right treatment tactics, patients are in a satisfactory condition, they remain able to work, they are on an outpatient observation.
The terminal stage proceeds with high temperature rises, progressive depletion, severe weakness, bone pain, rapid splenomegaly, enlargement of the liver and sometimes lymph nodes. Very quickly develops anemia with thrombocytopenia, which is complicated by the symptom of hemorrhagic syndrome, granulocytopenia and necrosis of mucous membranes. An increase in the number of blast cells is observed in the hematopoietic system of patients. As a rule, patients at this stage live up to twelve months.
Chronic lymphocytic leukemia at the beginning of its development is very difficult to identify. Only laboratory studies in which an increase in leukocytosis are found may signal a diagnosis of leukemia. However, a characteristic symptom of the disease is an increase in lymph nodes. Splenomegaly refers to the most common symptom, but the liver does not always increase. In the blood there is an increase in lymphocytes, prolymphocytes and sometimes lymphoblasts. When the disease develops, the overall level of gamma globulins decreases. And this, in turn, leads to frequent infectious complications, pneumonia, cytopenia, thrombocytopenia and anemia. In the terminal stage of chronic lymphocytic leukemia, sarcoma grows or a blast crisis occurs.
With hairy cell leukemia, the spleen and peripheral lymph nodes increase, and cytopenia is also markedly expressed.
Clinical symptoms in hereditary neurotropenia are characterized by a propensity for staphylococcal infections, severe alveolar pyorrhea. For the periodic form of the disease feverish condition is characteristic, but infections are attached strictly to the days of neutropenia.
Signs of leukemia
In case of leukemia, it is possible to distinguish the characteristic signs of this oncological disease of general and local manifestation. These signs of leukemia include: fatigue and weakness; insomnia or a constant desire to sleep; deterioration of concentration and memory; pallor of the skin and dark circles under the eyes; non-healing wounds; the formation of various hematomas on the body for no apparent reason; bleeding from the nose; frequently occurring SARS and infections; splenomegaly and enlarged lymph nodes, as well as the liver, a rise in temperature.
In laboratory blood tests, a decrease or increase in ESR, a different type of leukocytosis, thrombocytopenia and anemia is revealed.
The one or more of the above signs do not yet speak of leukemia. And in order to exclude or confirm the diagnosis, it is advisable to be examined in a specialized clinic and consult with professionals.
Leukemia in children
This disease refers to tumors that are characterized by uncontrolled division and growth of hematopoietic cells. Leukemia refers to clonal pathologies. Such a disease in children occurs in acute and chronic form, which differ in the ability of cancer cells to differentiate. If the tumor cells after the initial mutation do not undergo differentiation, but only reproduce themselves, then these are acute forms of leukemia. In children, they act as two main groups: acute lymphoblastic leukemia (80%) and acute non-lymphoblastic leukemia.
For many years, the causes of leukemia in children have been studied. But accurate data on this issue have not yet been established. It is suggested that the majority of acute leukemias in children can be programmed even during intrauterine development. But for the implementation of the pathological process, certain factors are necessary. The risk of acute leukemia in children whose pregnant mothers underwent an X-ray examination is much higher. In addition, if one of the odnoyaytsovyh twins develops leukemia for up to a year, then almost 100% can be argued that the second twin will fall ill with the same acute form of leukemia.
Also, many medical scientists prove that children with congenital anomalies in chromosomes are more at risk of contracting leukemia. This especially applies to diseases such as Fanconi anemia (the risk rises 200 times), Down's syndrome (20 times), Louis-Bar syndrome (70 times) and Blum's syndrome (200 times).
To date, the role of viral factors in the formation of acute lymphoblastic leukemias continues to be studied. In addition to infections, the influence of physical, chemical, social and economic factors on the development of acute leukemia is actively discussed.
Acute lymphoblastic leukemia in children is presented in the form of clonal division, reproduction and accumulation of immature blasts (lymph cells). The disease is more often diagnosed in boys and can occur at any age. Very often acute lymphoblastic leukemia affects children from two to four years (almost 50%). About 15% fall on ten years and 2% - it's up to a year.
The clinical picture of the disease consists of complaints from parents about the weakness of children, their malaise, reduced appetite and an unreasonable rise in temperature. Almost 60% of children have pale skin. All this indicates an increase in intoxication and anemia. Many children complain of pains in the bones, and in some cases there are very intense arthralgia and ossalgia, and this leads to a restriction in the movements.
In addition, there are pains in the spine and extremities, especially the lower ones. Osteoporosis and subacute proliferates of a pathological nature develop. On the roentgenogram, there are changes in the bodies of the vertebrae, osteoporosis and periostitis. Children also have proliferative syndrome, which is expressed in hepatosplenomegaly (80%), peripheral lymph nodes (50%) and mediastinal lymph nodes (10%). Sometimes the upper vena cava is squeezed as a result of an increase in the mediastinal lymph nodes. Almost 50% of children have hemorrhagic syndrome, which manifests itself in the form of nasal, renal, uterine bleeding and bleeding from the gums; petechial rash on mucous membranes and skin; hematomas and ecchymosis. In some patients, at the very beginning of leukemia, there are lesions of extramedullary nature. These include neuraleukemia (in 5-8%). It can be asymptomatic, in the form of a specific meningitis and with nausea, vomiting, pain in the head, with increased cytosis of the cerebrospinal fluid; encephalitic and meningo-encephalitic.
CNS lesion occurs diapedesis (through the vessels of the soft shell of the brain) and contact (from the bones of the skull to the hard shell of the brain). Other testicular lesions include testicles. In 2% of cases, boys are noted to infiltrate leukemia into the testicles. Clinically, they are observed to increase in the form of a dense, painless material. If a tumor is suspected, a biopsy test is performed. Very rarely, leukemia infiltrate is detected in Mikulich syndrome, in the heart, kidneys and lungs.
Laboratory diagnostics shows normochromic anemia (85% of children), leukopenia (20%), leukocytosis (50%), thrombocytopenia (80%). Virtually 98% of children with children in the peripheral blood have blast cells. In the bone marrow, a "leukemia gap" is observed.
Acute non-lymphoblastic leukemia in children is largely not characterized by clinical manifestations of acute lymphoblastic leukemia. It is characterized by a course with anemia, hemorrhagic and proliferative syndrome, as well as symptoms of intoxication. Very often, children develop DVS-syndrome as a result of the production of thromboplastin. This sign leads to bleeding profuse character. Granulocyte sarcoma is diagnosed in 15% of children, which is mainly localized on the skin and periorbital area. Neuroleukemia at the onset of the disease is detected in 20% of babies. Acute non-lymphoblastic leukemia proceeds with significant variability in hematological parameters.
Chronic myeloid leukemia in children is a blood clonal pathology that refers to chronic myeloproliferative diseases, including idiopathic myelofibrosis, essential thrombocytopenia and true polycythemia. Chronic myeloid leukemia develops after changes in the genetic nature of stem cells. These lesions begin to proliferate and produce hematopoietic cells, and they gradually displace the healthy cells of the hematopoietic system.
The course of this type of leukemia is characterized by a progressive nature. As a result, the disease occurs in three phases, such as chronic, acceleration and blast crisis. The chronic phase begins asymptomatically, and then the children complain of a temperature subfebrile condition and weakness, pain under the left rib in the area of an enlarged spleen. In the acceleration phase, specific intoxication and fever increase, ossalgia, splenomegaly, thrombocytopenia appear and leukocytosis rises. With a blast crisis, the symptoms of intoxication and splenomegaly continue to increase. There are extramedullary lesions.
All phases of leukemia proceed with its duration. For example, on a chronic, it takes from two to five years, and the other two are on average up to five months.
Treatment of leukemia
The disease of leukemia is dealt with by oncologists and hematologists. And pediatricians work with small patients - hematologists - oncologists.
In the fight against malignant neoplasm trying to get rid of leukemia and reduce the severity of signs of the disease, as well as side symptoms after the prescribed treatment.
One of the main types of therapy is polychemotherapy, during which a patient with leukemia is prescribed the administration of potent drugs that kill tumor cells. Treatment of leukemia may include a combination of different chemotherapy drugs. Chemitherapeutic drugs are prescribed both intravenously and orally. In most cases, the patient is placed a catheter in the subclavian zone for long-term therapy with intravenous medications. Sometimes it can even be sewn to the skin. Depending on the degree of severity of leukemia, the treatment is inpatient and outpatient.
If there is a threat of migration of tumor cells to the cerebrospinal fluid, patients with changes in cerebrospinal fluid, drugs are injected with puncture in the lumbar region, i.e. intrathecal polychemotherapy is performed. This method of treatment is very much in demand, because with the usual intravenous administration, medicines do not sufficiently destroy tumor cells that are localized in the brain and cerebrospinal fluid. And this, in turn, leads to a rapid and uncontrolled division and multiplication of leukemia cells. Sometimes the drug is injected into one ventricular cavity of the brain, and in this reservoir the drug is kept throughout the treatment.
After using chemotherapy, side effects appear in the form of hair loss, brittle nails, which stop growing, and become ribbed. Common side effects include digestive and intestinal disorders, irritation of the esophagus mucosa, susceptibility to infectious diseases, anemia and increased bleeding. Therefore, concomitantly prescribe antibiotics, transfusion of platelet and erythrocyte mass, inject drugs that enhance the production of new hematopoietic cells. For the treatment of chronic myeloleukemia, Imatinib is prescribed, which has good selectivity.
Chemotherapy is carried out in cycles a few days, and then a recovery period is given for three or two weeks. The course of therapy can include up to six cycles, and this will depend on the form of leukemia and risk factors. After each period of polychemotherapy, bone marrow samples are taken for the study.
In the treatment of leukemia, three phases of therapy are almost always used. These include: induction, consolidation and support. The first is characterized by the extermination of a large number of cancer cells, to speed up remission. For the second it is peculiar to find and destroy the remaining malignant cells. And in the last phase it is necessary to ensure a stable remission of the disease. Dosage of drugs at this stage is slightly lower than the first two, but the treatment can last almost two years.
Sometimes remission can be very short, so again start treatment, which was not previously applied. Very rarely, the second line of therapy leads to recovery. In this case, an effective treatment is a stem cell transplant.
In addition to chemotherapy drugs are simultaneously prescribed monoclonal antibodies, Interleukins and Interferon, which act on the principle of the immune system. They slow the reproduction of tumor cells a little, although they are accompanied by some undesirable effects.
Another way to treat leukemia is radiation therapy. If possible, try not to use this kind of treatment. The process of radiation exposure consists of a direction to an affected hot spot of high power. Such radiation destroys malignant bodies and has a negative influence, especially on the children's brain. Therefore, the dosage of irradiation is prescribed according to the indications, while protecting the unaffected organs.
The transplantation of stem cells is often performed after the use of high-dose chemotherapy.
The surgical method of leukemia treatment is used for splenectomy. This operation is prescribed for splenomegaly and disruption of the work of nearby organs.
After the course of treatment, all the examinations are repeated to determine the effectiveness of the treatment. In many patients, the number of malignant cells decreases, and in some cases they completely disappear. There comes a remission, in which the patient is observed by an oncologist and periodically passes the examination until the appearance of the first symptoms of leukemia. And patients who fall into an increased risk group with an expected asymptomatic period should immediately undergo a stem cell transplant after a course of chemotherapy.
In patients with leukemia, absolute remission occurs in 95% of cases. 75% have a five-year survival after treatment, they are considered healthy. When there are recurrent processes, in most cases it is possible to achieve a second remission. Such patients are considered candidates for bone marrow transplantation, and they have a survival probability of about 60%.
In adults, acute acute lymphoblastic leukemia is rarely diagnosed. The five-year survival rate in this case reaches 20%.
In many cases of acute myeloblastic leukemia, complete remission occurs in 65% of patients. Various post-induction schemes on average prolong the period of remission to a year or fifteen months, and 30%, in general, there are no relapses up to two years. And it is possible to have a stable remission.
Adverse signs in the prognosis of leukemia include: men and age after fifty years; megakaryoblastic leukemia and erythroblast leukemia; hyperleukemia, thrombocytopenia, neuraleukemia.
Lethal outcome occurs as a result of renal and cardiac insufficiency, hemorrhagic syndrome, neuroleukemia, infectious complications and acute adrenal insufficiency.
With blood leukemia, there are three types of remission, which include clinical, clinical-hematological, cytogenetic or molecular. With clinical remission, hematologic changes persist with no clinical symptoms. Clinico-hematologic remission does not reveal clinical and laboratory signs of leukemia. With cytogenetic remission there are no molecular disorders, which are determined before the start of treatment.
Leukemia is characterized by relapses, which can be either early or late. The early ones appear in the process of treatment, and the later ones appear after it.
Absolute recovery can be said after a five-year absence of relapses from the end of the course of therapy.