
Created by: Hellenbrecht (ELIC Project 2) , generated 2007/01/18, last changed: 2007/12/17
Authors: European LeukemiaNet, Project 6, Acute Lymphoblastic Leukemia (January 2007)
Patient information in different languages
Akutni lymfoblastickou leukemii
(230KB)
Acute lymphoblastic leukemia
(144KB)
leucémie lymphoblastique aiguë
(144KB)
Akute lymphatische Leukämie
(119KB)
Leucemia acuta linfoide
(103KB)
Leucemie acute limfoblastic
(131KB)
LEUCEMIA AGUDA LINFOBLÁSTICA
(154KB)
Acute lymphoblastic leukemia (ALL) is a severe blood disease caused by uncontrolled proliferation of immature cells, known as lymphoblasts, in the bone marrow. Although the diagnosis of this disease has a great physical and emotional impact on you and those around you, you should be aware that there are currently many therapeutic tools which enable an increasingly greater percentage of patients to be controlled and even cured.
The objective of this manual is NOT to substitute the work of the medical team who attends you in regard to being the only source of information of your disease, but rather it is to provide complementary information to help you understand aspects related to the diagnosis and treatment of ALL and to even facilitate communication with your physician. Please read the manual carefully. However, you should remember that the best information is provided by the members of the medical team caring for you. Do not hesitate to ask and request information about any aspect related to the diagnosis, prognosis or treatment of your disease.
Acute leukemias are uncontrolled proliferations of malignant, immature cells (known as blasts) of the hematopoietic system. In the hematopoietic system, different types of blood cells are developing from one basic cell type (pluripotent stem cell, which is located in the bone marrow). The blood cells develop step by step, becoming more and more mature. Only at the end of their development, they are ready to play their role in immune defense. Sometimes the regularly mechanisms of this system are failing. In contrast with chronic leukemias, acute leukemias usually develop in only a few weeks and rapidly lead to the appearance of symptoms, severe in some cases, making diagnosis and rapid treatment extremely important. There are two large groups of acute leukemias: acute lymphoblastic leukemias (ALL) and acute myeloblastic leukemias (AML) and within each of these two large groups there are numerous subtypes based on the characteristics which each malignant immature cell has. In the cases of acute lymphoblastic leukemia (ALL), the immature cell which multiplies uncontrollably is the precursor of the lymphocytes (known as lymphoblasts). The lymphocytes are a type of blood cells which make up part of the immune system and are mainly localized in the bone marrow, the blood, the lymph nodes and the spleen.
As a consequence of this uncontrolled multiplication of the lymphoblasts the following occurs:
The uncontrolled proliferation of abnormal cells (blasts) which takes place in ALL is the result, as in other types of cancer, of alterations in the mechanisms of control and regulation of cell growth and differentiation. These mechanisms are regulated by genes (fragments of the chromosomes of the cells formed by DNA which contain the information on all the functions that each cell type carries out). The alteration in these genes leads to their transformation into malignant cells by mechanisms which we only partially understand. At present there are very specific techniques such as conventional cytogenetics, in situ hybridization or molecular biology techniques which make it possible to study the genes and chromosomes. In this way alterations which help to make the diagnosis and classify the type of ALL may be detected and treatment may be administered on the basis of these findings.
The causes as to why these alterations in the genes and chromosomes of the cells are produced and lead to the appearance of the ALL are not completely understood. It is thought that both genetic and environmental factors (for example, ionizing radiation or toxic substances such as derivatives of benzol and pesticides) and even infections (as in some viruses) may play a role. Some known carcinogenic substances such as tobacco and alcohol do not increase the risk of ALL. However, in most cases it is not possible to discover the cause of the leukemia. Although some genetic abnormalities are found in leukemias, it is important to emphasize that ALL is not a hereditary disease. In addition, as ALL is not an infectious disease, there is no risk to transmit the disease.
Many types of ALL may be differentiated based on the characteristics the lymphoblasts have on microscopic observation: the presence or absence of surface cell markers and the presence of gene and chromosome alterations. Therefore, the classification of the type of ALL requires the use of several complementary techniques including:
SUBTYPES | |
|---|---|
Acute lymphoblastic leukemias |
B-precursor leukemia |
T-precursor leukemia | |
Burkitt cell leukemia |
TYPE AND SUBTYPE |
FREQUENCY |
|---|---|
B cells ALL | |
Pro-B or pre-pre-B |
5 % / 20 % |
T cell ALL | |
Pro-T |
15 % / 25 % |
ALL: acute lymphoblastic leukemias
EGIL: European Group for Immunologic Classification of Leukemias
By using these methods, the disease ALL can be divided in two main groups and two further groups of smaller size:
There are two special types of ALL which are clearly differentiated from the remaining types by their characteristics. As you will see later, the treatment of these forms of ALL is very different from the remaining subtypes of ALL:
The symptoms and signs of ALL are derived from the infiltration of the bone marrow and other tissues and organs as a consequence of the uncontrolled multiplication of the lymphoblasts (leukemic cells).
On occasions, however, leukemia may be detected by accident when having analysis for any other reason but its presentation is normally accompanied by other symptoms, with the following being of note:
These are symptoms derived from an alteration of the general status perceived as a sensation of not feeling well and generally include:
Some types of ALL produce special symptoms. For example, ALL which originates in the T lymphocyte precursors (T-ALL) more often affect males than females and in more than one half of the cases a tumor in the mediastinum (the space of the thorax between the lungs) is found. On the other hand, mature B-ALL or Burkitt’s leukemia may be accompanied by a large tumor in the abdomen in addition to tan increase in the size of the liver and the spleen.
As in most diseases, the diagnosis is first carried out by interrogating the patient and performing a physical examination in search of the symptoms and signs described above.
To confirm the definitive diagnosis of ALL it is necessary to do only a few tests. Although these tests are practically without risk, they may or may not be a little bothersome. These tests consist in a blood analysis, bone marrow aspirate (also called myelogram) and a lumbar puncture.
The blood analysis usually shows:
The bone marrow aspirate or myelogram consists in doing a puncture of the bone, generally in the sternum or the posterior iliac crest, with local anesthesia, and thereafter extracting a few milliliters of blood from the medulla of the bone. By microscopic examination of the medullar blood the doctors will try to identify the lymphoblasts which usually make up more than 20 % of all the cells of the bone marrow. In addition to identifying the lymphoblasts by morphology (by microscopy), other complementary techniques described above (cytochemistry, flow cytometry, cytogenetics and molecular biology) should be undertaken. In this way physicians are able to determine the type of ALL and establish the most adequate treatment.
Lumbar puncture: This is a puncture performed in the area of the back, at the height of the last lumbar vertebrae which may be carried out with the patient being seated or laying on his/her side. The technique is similar to that used to give epidural anesthesia. A needle is introduced into the space located between two vertebrae and a few milliliters of cerebrospinal fluid (the fluid which surrounds the brain and spine) are withdrawn. This fluid is always examined when making the diagnosis of ALL to see whether it contains lymphoblasts. If so, chemotherapy may be directly administered into the nervous system to destroy these lymphoblasts (made by several of these punctures). If the fluid is normal, preventive chemotherapy is also administered into the nervous system, although less often. The secondary effects of this procedure include headache which may last a few days later but is easily controlled with analgesics.
The treatment of ALL is based on the administration of chemotherapy, that is, drugs which have the capacity of destroying the tumor cells (the lymphoblasts). Nonetheless, the treatment to be administered will depend on the specific type of ALL in addition to other important factors such as the age of the patient or the simultaneous presence of other diseases (for example, cardiac or pulmonary diseases). Moreover, together with chemotherapy, other aspects are important such as the need for blood or platelet transfusions or the administration of antibiotics or other drugs needed to control the complications and the secondary effects derived from chemotherapy. It may be a normal practice in some countries to request written authorization from the patient to administer the treatment or to do tests and explorations such as the placement of a venous catheter or to perform a biopsy.
In general, the treatment requires the placement of a central venous catheter (a tube of flexible material inserted into one of the large veins, generally the jugular or the subclavian vein) through which all the treatments may be administered and the blood analysis may be extracted when necessary, thereby avoiding the bother derived from the multiple venous punctures.
In general lines, the treatment has several phases in all the types of ALL. The first phase is known as induction treatment, the second is intensified treatment (also known as consolidation) and the third phase is maintenance treatment. In some types of ALL there is a high risk of relapse and after the consolidation phase it may be necessary to perform a transplantation of hematopoietic progenitors (also known as hematopoietic stem cell transplantation, HSCT). The global duration of all the treatment (including all the phases) is lengthy and may last up to 2 years. Some of the phases are administered under hospital admission with rest periods of 1 to 3 weeks between each cycle. During these rest periods the patient may remain at home. It is very important to follow strictly the treatment plan, and not prolong breaks between cycles. The maintenance phase is usually done completely on an outpatient basis. Table 3 shows the main drugs used in the chemotherapy usually given for the treatment of ALL. Likewise, table 4 shows a list of drugs for the treatments of ALL which are still under study. Below you will find a brief description of each of the phases of treatment:
Chemotherapy drugs | |
|---|---|
Cyclophosphamide |
L-asparaginase |
Other drugs |
|---|
Alemtuzumab |
As already mentioned, in addition to chemotherapy treatment, other complementary or support treatments are important because they help to control the secondary effects and complications. These complementary treatments include the following:
Most of the complications are due to the administration of chemotherapy which, in addition to provoking the destruction of abnormal cells (lymphoblasts), affects the production of the remaining blood cells and other tissues and organs. Most of these complications are reversible and may be successfully treated. The following are some of these complications:
With regard to work, the patient normally remains off work during the treatment, but may return to work on finishing treatment based on his/her general status and the activity the work involves.
In some cases, a relapse of leukemia may be possible on completion of the treatment. However, the longer the time after the termination of treatment, the lower the possibility this will occur. This is why periodic controls are carried out during several years. In the case of relapse, the medical team will indicate the available therapeutic options.
Despite all the complications, an ever increasing number of patients are disease free in the long-term and only require periodic controls throughout their lifetime. In children the global rate of cure from ALL is around 70 %, while being 35 % to 40 % in adults. In any case, these results depend on the subtype of ALL as well as the presence of determined prognostic factors such as age, the existence of particular chromosomal alterations, the speed of treatment response, and the degree of elimination of the occult disease (also known as residual disease).
Acute lymphoblastic leukemia with Philadelphia chromosome and acute Burkitt’s lymphoblastic leukemia
Relapse of leukemia indicates that the treatment administered did not completely eliminate the leukemic cells. The manifestations of relapse may be similar to those at the initiation of ALL or may occur with different symptoms (for example, relapse only in the nervous system). Bone marrow aspiration tests are necessary to determine if there is isolated relapse in the bone marrow or there are other sites of relapse.
Whatever the localization of the relapse, chemotherapy will most likely have to be given again. In addition to some aspects such as the time which has passed since finalizing the previous treatment until the relapse (the prognosis is generally better with a late relapse, that is, years after having finished the treatment, than an early relapse of only a few week or months after), the localization, previous treatment administered, and the general status of the patient should be taken into account. A relapse means that the leukemia has a high risk of presenting successive relapses in the future. Therefore if necessary, and if the patient can tolerate it, more vigorous chemotherapy treatments and probably an allogeneic transplantation (if there is a compatible donor) are performed. It is also important to think about treatment with new drugs under evaluation in clinical trials.
The controls that are made after finishing the treatment will normally be undertaken on an outpatient basis. The periodicity and the type of controls vary based on the patient, the complications and the secondary effects presented, as well as the type of treatment administered (transplant, chemotherapy alone, etc.). A physical examination, blood analysis and a revision of the treatment, if necessary, will be made on each appointment. On occasions, other explorations will be requested such as bone marrow aspiration.
The quality of life of the patient may be more or less affected depending on the treatment and the complications presented.
In patients who undergo a hematopoietic stem cell transplantation, if there are no serious complications, the patients may return to their normal life after a period ranging from 6 to 12 months. The most frequent problems noted by the long-term survivors are emotional, followed by fatigue, eye problems, sleep disorders and difficulties in concentration and the memory. In addition to these problems, the following are also relatively frequent:
In the patients who only receive chemotherapy the long-term complications are less frequent and recovery is more rapid because of the lower intensity of treatment received and these patients are able to return to normal activity within a shorter period of time. In addition to the already mentioned emotional problems and fatigue or disorders in sleep, concentration and memory, we should add a greater incidence of cataracts (because of the prolonged administration of corticoids) or the always present possibility of relapse of leukemia (also lower the longer the time that has passed since the completion of treatment). To the contrary, sterility and other hormonal problems are generally transitory. Some patients may develop osteonecrosis (loss of intact and healthy bone tissue in articulating joints) of the hip, shoulder, or other articulated joints.
Receiving the diagnosis of ALL is mostly a shock. It often causes severe emotional distress and it is quite possible, that you will feel helpless and desperated. Maybe you ask yourself “Why does this happen to me?”
The following suggestions may help you to be able to adjust to the diagnosis:
Below you will find some addresses of interest from which more information may be obtained: