While solid tumors such as lung cancer and breast cancer account for the majority of cancers in adults, various forms of leukemia are among the most common malignant neoplasms in children.
Here the acute forms ALL and AML are in the foreground. The aim of treating leukemia in children is to contain the proliferating cells and, if necessary, to replace their progenitor cells with new stem cells .
Leukemia treatment in children – the most important things at a glance!
- The aim of treating childhood leukemia is to completely eliminate the cancer cells.
- This can be achieved through intensive chemotherapy , which is particularly stressful for the patient due to the impairment of blood clotting and the immune system.
- In some cases, a preliminary therapy is used as a preliminary stage, which already kills a large part of the tumor cells.
- High doses of other cytostatics eliminate most cancer cells. To ensure the success of the treatment, further chemotherapy is used, which also eliminates the last of them.
- In the event of a recurrence, an allogeneic stem cell transplant can be used to replace the damaged stem cells in the bone marrow.
Course of leukemia treatment in children
The acute leukemias ALL (acute lymphoblastic leukemia) and AML (acute myeloid leukemia) make up the majority of all childhood cancers. ALL is the most common, accounting for 80 percent of all leukemias, followed by AML.
Both forms are characterized by an acute, rapid course of the disease. While the chronic forms of leukemia, which mainly occur in adults, develop unnoticed over years and only gradually lead to health problems, AML and ALL progress very quickly within a few weeks and months.
If there is no therapy, immature progenitor cells of the white blood cells spread throughout the body without being able to take over the functions of the immune system.
The overgrown leukocytes are no longer sufficient to ensure adequate defense against infection, and the proportion of red blood cells can no longer do its job satisfactorily. The consequences are susceptibility to infections, paleness, exhaustion and weight loss. Even minor infectious diseases are fatal.
Exactly how pediatric leukemia treatment is treated depends on numerous factors that the treating oncologist must consider.
These include the type of leukemia, general condition of the patient and age. The sooner therapy is started, the better the chances of recovery.
How long does childhood leukemia treatment take?
The duration of the entire therapy for ALL is about two years. The intensive inpatient phase with a stay in the hospital lasts about six months, followed by around one and a half years of outpatient treatment.
In the case of AML, the duration of therapy is around one and a half years , provided there is no relapse and no stem cell transplantation is necessary.
Course of leukemia treatment in children
Depending on the course of the disease, state of health and a more precise classification of the leukemia, different therapy phases are used.
pre-therapy
The aim of the preliminary therapy is to carefully reduce the proliferating leukemia cells. This is necessary above all in patients whose internal organs have greatly enlarged as a result of accumulations of leukemia cells. Rapid elimination would have an effect on blood clotting and would damage the kidneys due to the uric acid produced in large quantities during cell breakdown ( cell decay syndrome ).
The preliminary therapy consists of a short chemotherapy usually with one or two cytostatics and usually lasts only one week.
induction therapy
Induction therapy is the actual, very intensive chemotherapy that kills the fast-growing tumor cells. It takes about four weeks for ALL and eight weeks for AML. During therapy, the success of the treatment is monitored using bone marrow examinations . Ideally, the cancer cells are pushed back and normal blood formation resumes its work.
The high-dose chemotherapy is particularly stressful for the patient and primarily affects the immune system and blood clotting. Protection against infections is therefore particularly important in this phase.
consolidation therapy
During the consolidation phase, sometimes other cytostatics are used, sometimes even higher dosages. The aim of this measure is to consolidate, i.e. strengthen, the remission of the tumor cells achieved by the previous therapy and induction therapy. This is achieved by killing other tumor cells that survived the first round of chemotherapy.
ZNS-Therapie
The blood-brain barrier ensures that many drugs, including many chemotherapeutic agents, do not get into the brain. The CNS therapy should ensure that leukemia cells that are present in the central nervous system are also killed, as they would cause a relapse within a short time – even if no immediate infestation was found. Because just a few cells are sufficient for renewed tumor growth.
Special cytostatics that can cross the blood-brain barrier are used for CNS therapy.
In addition, these can be introduced directly into the central nervous system by injecting them into the cerebrospinal fluid (liquor) that flows around the spinal cord and brain. This is done using a lumbar puncture on the back ( intrathecal chemotherapy ). If an infestation of the brain with leukemia cells is detected, radiation therapy is added.
Reinduktionstherapie
Renewed induction therapy improves the success of treatment in many forms of ALL. The procedure is similar to that of the first induction therapy and aims to safely and completely eliminate all remaining cancer cells. This measure is particularly recommended for high-risk patients.
maintenance therapy
Chemotherapy only reaches those cancer cells that are growing at the time of treatment. It hardly touches resting cells. Therefore, there is a risk that tumor cells were in a dormant state during the therapy and start growing again after the chemotherapy.
To prevent this, the main treatment for AML and ALL is followed by maintenance therapy . It consists of a much lower dose and less intensive chemotherapy and is usually carried out on an outpatient basis. If there is no relapse after a total of two years of therapy, the leukemia is considered cured and further maintenance therapy can be dispensed with.
Stem cell transplant
Most ALL patients can be permanently cured with intensive chemotherapy. Nevertheless, about 15 percent relapse (recurrence). In addition to chemotherapy and radiation therapy, allogeneic stem cell transplantation is available as a therapy option.
Before the actual stem cell transplantation, the stem cells of the bone marrow are completely eliminated by radiation and/or chemotherapy. After that, the patient must be strictly shielded, since even small infections can no longer be fought due to a lack of immune system and could be fatal.
After the implantation of new stem cells, the blood-forming system grows again. Therefore, the blood group can change and a completely new immune system builds itself.
What is the prospect of treating leukemia in children?
Modern therapy methods have significantly improved the survival rate of children with leukemia. Novel chemotherapies and stem cell therapy play a key role in this. In the 1960s, the median survival time for children diagnosed with ALL was four months; today, 90 percent of those affected can be permanently cured. The prognosis for AML is less favorable, with a cure rate of over 70 percent.
Sources, links and literature
- Charlotte Niemeyer, Angelika Eggert (ed.): Pediatric hematology and oncology. 2nd Edition. Heidelberg 2018: Springer-Verlag. ISBN: 978-3-662-43685-1.
- Dietrich Reinhardt, Thomas Nicolai, Klaus-Peter Zimmer: Therapy of diseases in childhood and adolescence. 9th edition. Heidelberg 2014: Springer Verlag. ISBN-10: 3642418139.
- Helmut Gadner, Gerhard Gaedicke, Charlotte Niemeyer, Jörg Ritter (eds.): Pediatric hematology and oncology. Heidelberg 2006: Springer Verlag. ISBN-10: 3540037020.
- Lorenz Grigull, Benedikt Wronski: Piggyback through pediatric oncology: Beginner’s book for the pocket. Heidelberg 2016: Springer-Verlag. ISBN-10: 3662499096.
- Paul Imbach, Thomas Kühne, Robert J. Arceci (eds.): Compendium Children’s Oncology ie. 3. Edition. Heidelberg 2014: Springer-Verlag. ISBN-10: 3662434849.
- Working Group of Scientific Medical Societies eV (AWMF):
- Long version of the guideline ” Acute lymphoblastic leukemia – ALL – in childhood “.
- Long version of the guideline “ Acute myelic leukemia (AML) in childhood.
