Leukemia in children

introduction

Leukemia, i.e. cancer of the white blood cells, is one of the most common cancers in children, with the subtype ALL (acute lymphoblastic leukemia) being by far the most common.The disease usually manifests itself as anemia, an increased tendency to bleed and an increased tendency to become infected.
The diagnosis is usually made by a blood test and a bone marrow puncture. With aggressive and rapid therapy, the chances of recovery are very good.

definition

Leukemia, popularly better known as "blood cancer“Is the most common cancer in children and adolescents. So she stands with about 34% of all childhood cancers first of all. But what exactly is leukemia?

The disease finds its origin in the bone marrow, the location of the Blood formation. There is an uncontrolled release of immature progenitor cells into the bloodstream. These leukemia cells, too Blasts called, disrupt the complicated process of blood cell maturation and formation. As a result, the healthy blood cells, such as. red blood cells (erythrocytes) or platelets (thrombocytes) no longer sufficiently manufactured become. It is named after the white blood cells (leukocytes), from whose cell line the functionless leukemia cells originate.

There are roughly two groups of types of leukemia: The Acute and the Chronic leukemia. Both groups will continue in a) myeloid or b) lymphatic leukemias divided so that at the end there are 4 large groups:

• the Acute myeloid leukemia (AML)
• the Acute lymphocytic leukemia (ALL)
• the Chronic myeloid leukemia (CML)
• and the Chronic lymphocytic leukemia (CLL)

The acute lymphoblastic leukemia, ALL for short, is that most common form of leukemia with children. Only 10-20% of all childhood leukemias are caused by other types of blood cancer! Overall, ALL accounts for a third of all cancers in children and adolescents. In the case of ALL a malicious change takes place in Lymphocyte precursor cells, a subgroup of white blood cells.

causes

To date, the causes of leukemia are largely unknown. However, factors are known that increase the risk of developing leukemia in children:

Hereditary disposition

Is leukemia no hereditary disease in the classic sense. However, there are some hereditary diseases that play an important role in the development of the disease. It is known that children with Down syndrome (trisomy 21) are about 20 times more likely to develop leukemia. Other, rarer hereditary diseases such as neurofibromatosis type 1 or Shwachman-Bodian-Diamond syndrome also increase the risk.

In addition, in some children genetic changes identify those associated with acute lymphoblastic leukemia (ALL). However, these children only develop ALL much later and not necessarily. So seem external factors also to have an important meaning.

Radioactive radiation

The latest studies show that children who grow up near a nuclear power plant have a measurably higher risk of developing leukemia. Similar effects of radioactive radiation are already known to the nuclear disasters, such as in Hiroshima or Chernobyl.
Are just as harmful to the unborn child X-ray examinations of the expectant mother.

Symptoms

Symptoms of ahave leukemia mostly develop within a few weeks. At chronic leukemia however, symptoms develop much slower. Leukemia cells can affect all other organs in addition to the bone marrow. Thus, the possible symptoms are very broad.

Often the children fall at the start of both types of leukemia due to unspecific complaints, such as Fatigue, loss of appetite, or listlessness on. Small children often no longer want to play or walk.

The other symptoms arise from the fact that the healthy formation of red and white blood cells and platelets in the bone marrow is suppressed by the degeneration of the leukemia cells.

• Often the parents get a striking one paleness your child's eye. This can be explained by the reduced number of red blood cells (erythrocytes) (see: Anemia).
• Since functioning white blood cells (leukocytes) decrease at the same time, the immune system increasingly declines. Children then often suffer from stubborn and feverish infections.
• Numerous bruising, bleeding gums, or frequent nosebleeds may be a sign of a low number of blood platelets (thrombocytes) (see: Thrombocytopenia).
• When the leukemia cells migrate into bones, lymph nodes or other organs (spleen, liver), the children suffer from different degrees of severity Pain. Many parents report about stomach pain in their child, but also about bone pain in the arms or legs.

Often it comes to Lymph node swelling e.g. in the neck or groin area. Infestation of the nervous system or the eyes, which can manifest itself in severe headaches or visual disturbances, is less common.

In a special form of leukemia, T-ALL, there is an infiltration of the Thymus. The thymus is a small organ in the chest that plays an important role in the maturation of the child's immune system. It regresses on its own in the course of young adulthood. If the leukemia cells of a T-ALL attack the organ, the children suffer Shortness of breath.

In chronic leukemia, which is rarer in childhood than in adulthood, symptoms are caused by too many cells (normal blood cells and leukemia cells) in the blood. It can too painful vascular occlusions come.

Nevertheless: symptoms of leukemia are common to every child individually different. Even the presence of one or more symptoms is there absolutely not proving for the presence of the disease! Often, comparatively harmless, more frequent diseases are hidden behind the symptoms. Nevertheless, you should consult a doctor as soon as possible. This is the only way to find the cause of the symptoms.

More information can be found here: How do you recognize leukemia?

diagnosis

The first step in diagnosing childhood leukemia is to do a detailed survey of the previous one Complaints and the course of the disease (Anamnese). If leukemia is suspected, one is followed detailed examination of the blood. Among other things, the blood count, i.e. an overview of the individual blood cells (leukocytes, erythrocytes, thrombocytes), plays an important role here. If the evidence of leukemia in the child grows, a direct transfer is made to a Children's clinic with a corresponding department (Pediatric Oncology and Hematology).

Bone marrow puncture

Since the bone marrow is always the source of leukemia, the next diagnostic step is one Bone marrow puncture. In a short intervention, the smallest can be done Tissue samples from the iliac crest or sternum taken. In newborns or infants, the sample may be taken from the shin. Since bone marrow aspiration can be stressful and painful for many children, it is done either in General or local anesthesia. The bone marrow obtained in this way is then examined in fine tissue and prepared for further, complex examinations. Mostly the first assessment through the microscope very quicklyso that the diagnosis of leukemia can usually be made shortly after the bone marrow aspiration.

In addition to the bone marrow, other organs can also be affected by the leukemia cells. Ultrasound examinations, MRI images or one Nerve fluid withdrawal (Lumbar puncture) can provide a comprehensive overview of the progress of the disease.

blood values

Leukemia can change blood counts in children in many directions. However, the focus is often on white blood cells, also called leukocytes. The word "leukemia" comes from ancient Greek and means "white blood" when translated. The white blood cell count does not always have to be high, however. If there is leukemia, they can White blood cells decreased, normal or increased be. The presence of immature precursor cells (which normally only occur in the bone marrow) in the blood is much more informative. This means that the so-called Blasts in the blood be detected.

In many children, the value of the red blood pigment (hemoglobin) falls below the normal value - it comes to one Anemia. Furthermore, a drop in blood platelets can be observed relatively frequently. One then speaks of one Thrombocytopenia.

Blood values, however, play an important role not only in diagnosis, but also in leukemia therapy. Because during the aggressive chemotherapy there is not only an intended destruction of the leukemia cells, but also an inevitable, severe impairment of the remaining blood-forming cells. For all children under therapy, the Blood values ​​at very short time intervals to be controlled!

treatment

Leukemia is a very aggressive disease. Therefore, the treatment must be started as soon as possible. Justified suspicion is enough to initiate therapy in affected children.

Basically, the therapy should only be in one specialized treatment center for children and adolescents with cancer (pediatric hematology and oncology), these are mostly located at university clinics and large hospitals.

The most important pillar of therapy is the chemotherapy The aim is to destroy the leukemia cells as completely as possible. Only in this way can the bone marrow resume its normal blood-forming function. To get the best possible effect, be several, different chemotherapy drugs, also called cytostatics, used in combination. Then one speaks of a "polychemotherapy".

You can find more information on this topic here: Performing chemotherapy

If that central nervous system (i.e. the brain and the spinal cord) is affected by leukemia cells, a Irradiation of the skull respectively. However, since many late complications can arise, the decision must be carefully considered. Basically however no child in the 1st year of life skull irradiated.

In certain cases a Stem cell transplant necessary. The first step is high-dose chemotherapy designed to destroy all cells in the bone marrow, followed by a bone marrow transplant in a special center.

You can find more information on this topic here: Bone marrow donation

In Germany, almost all children and adolescents with leukemia are in so-called "Therapy Optimization Studies" treated. The aim is to ensure the best possible treatment for sick children. One prevails within the controlled clinical studies great exchange of information. In this way, treatment based on the latest scientific knowledge can be made possible.

Duration of treatment

Unless radiation or bone marrow transplantation is necessary, therapy for leukemia in children takes about 2 years. It is divided into different phases that last about half a year and are in principle associated with constant hospitalization.

In the final phase of treatment, the Maintenance or long-term therapy, the children receive about 1.5 years of relatively moderate chemotherapyi.e. relatively small doses. Since the cytostatics are usually administered in tablet form, most of the last part of the treatment can be done at home respectively.

In the case of an additional bone marrow transplant, the duration depends on the patient matching donor search from. Once a suitable stem cell donor has been found, the therapy lasts approx. 2-2.5 years.

Hair loss side effect

As part of the treatment for leukemia, children experience hair loss. Like almost all chemotherapy drugs, the drugs used in leukemia therapy are very aggressive in the human body. Unfortunately, they do not only work against leukemia cells. In particular rapidly dividing cells, how Mucous membrane cells or Hair root cells are also affected. As a result, the children lose all hair, including eyelashes and eyebrows, within a short period of time.

Although completely painless, this hair loss is a serious side effect for many children and their families. Fortunately, hair grows back quickly after the end of chemotherapy. For the time during therapy, there is also the possibility special wigs.

You can find more information on this topic here: Chemotherapy side effects

Other side effects

Since the therapy of leukemia has to be very aggressive, there is unfortunately many side effects. One of the main problems is a maximally "shut down" immune system. Affected children are very susceptible to e.g. Pneumonia or even blood poisoning.

In order to be able to treat the side effects (nausea, vomiting, inflammation of the oral mucosa, bleeding, anemia, infections ...) better, the so-called "Supportive" therapy a high priority. This includes all supportive measures, such as medication against nausea and vomiting, antibiotics against infections, etc.
Affected children should have as little contact as possible with potential germs during treatment, which is why they usually become during the course of chemotherapy isolated.

Furthermore, both chemotherapy and radiation therapy can be used in the course of life other tumors arise.

Chances of recovery

Fortunately, there have been numerous advances and improvements in the treatment of childhood leukemia over the past few decades. Current, are about 80-90% of sick children are free of leukemia 5 years after diagnosis. In this context, one also speaks of the 5-year survival rate. With adequate treatment, leukemia in children is definitely curable! Without suitable therapy, however, acute leukemia is always fatal.

Nevertheless, it cannot be determined from this number whether an individual child actually survives the disease unscathed. Individual influences such as childhood, extent or form of leukemia determine the curability. In this context, one speaks of “prognostic factors”.

• As positive factors are rather low levels of white blood cells, no involvement of the central nervous system or an age of onset between 2-10 years.
• Unfavorable prognostic factors would be e.g. central nervous system involvement or T-ALL. However, the factors mentioned are based on statistics and experience.

So it is of course possible for children with negative prognostic factors to be cured and vice versa.

About each 7. The child suffers from a relapse. One then speaks of a relapse. They usually appear within 2-3 years after the initial diagnosis and have poorer healing prospects.