General
also called leukemia leukemia (Leukemia), this term is derived from the Greek
word, in fact, his intention is to white blood incidence of malignant tumors in
children with leukemia living in the first place, accounting for about 30% of
childhood cancer, alone as Taiwan is
concerned, there are about 150-200 new cases per year. In recognition of childhood leukemia before the
first known human blood components. The main function of the bone marrow in the
manufacture of red blood cells, white blood cells and platelets. Red blood cells responsible for oxygen
transport, the supply needs of the body, and the carbon dioxide is discharged
via the lungs. White
blood cells can be divided into granulocytes, lymphocytes and monocytes, these
blood cells in the body against foreign microorganisms can be a great
responsibility. Platelets clotting
function, you can prevent the body's bleeding. Under normal circumstances, the bone
marrow cells can be differentiated into shoots various functions above blood
cells. In acute
leukemia, these large numbers of irregular bud cells proliferation,
differentiation and maturation of not only did not, but cancerous proliferation,
resulting in the blood and bone marrow can find these immature bud cells.
And
this cell line will continue to proliferate, and kept crowding out normal cell
proliferation, this way, the bone marrow was occupied by a number of leukemia
cells and normal hematopoietic cells replace those positions, they can not
produce normal bone marrow blood cells in the peripheral blood
appears anemia, thrombocytopenia and neutropenia phenomenon. Bud cells in the bone marrow if more than 30%,
it is called acute leukemia.
Cause of disease
Still not entirely clear. Many reasons will have a higher chance of causing leukemia, for example: 1. Several congenital diseases, such as: Down syndrome, congenital free nor full, congenital aplastic anemia and other diseases, the chance to get much of leukemia increases. 2 radioactive substances, such as Hiroshima and Nagasaki bombings, making the local People's Congress to increase the risk of leukemia. 3 structural changes within the chromosome genes directly cause cell malignant transformation, and increase the chance of leukemia. 4 Many of the drug or chemical toxins also cause leukemia, such as: Benzene and alkylating agents. But the vast majority are still unexplained.
Classification
According to the clinical course of the disease and leukemia cell types can be divided into four categories: 1. Acute lymphoblastic leukemia (ALL): The most common childhood cancer, accounting for approximately 75% of all childhood leukemia. (2) acute non-lymphocytic leukemia, also known as acute myelogenous leukemia (AML): accounting for about 20% of all childhood leukemia. 3. Chronic myelogenous leukemia (CML), accounting for about 3% of all childhood leukemia. 4 chronic lymphocytic leukemia (CLL): rare in children. The incubation period is generally believed that acute leukemia only about four to eight weeks time after onset if not treated, will soon lead to organ failure, fatigue, anemia, excessive bleeding and infection, survival time of about six months, it is called acute leukemia . While chronic leukemia is the long incubation period, obvious symptoms, if not treated after the onset of the survival time of up to two to three years, so called chronic leukemia.
Clinical
The same as the general cancer, leukemia, often early detection and diagnosis is not easy, sometimes in the case of no symptoms, and occasionally the routine physical examination or blood was found; the most common symptoms are cold like symptoms, such as loss of appetite, fever, fatigue, or bone pain and so on. Therefore, if the phenomenon of unexplained high fever, you should seek your physician, if there is less abnormal, should be vigilant: pale face or lips: Because red blood cells decreased, hemoglobin decreased. easy bleeding, skin bruising: Because thrombocytopenia. unexplained fever: Due to the rapid growth of leukemia cells, destruction, so that metabolic hyperactivity rules. lymphadenopathy: But do not feel pain or tenderness, usually occurs in the neck, armpit or groin. weight loss or growth arrest. bone pain: leukemic cells accumulate in the bone marrow, causing bone marrow expansion, periosteal traction or leukemia cells by a direct violation of the bones, causing pain. This pain especially in the knees and ribs on the bottom of the sternum of the most obvious. organ enlargement: a rapid increase in leukemia cells, violations to the liver, spleen, lymph nodes, thymus or meninges, gonads, kidneys, causing organ enlargement.
gingival hypertrophy: non-lymphocytic leukemia, can still infringe on the gums, the gums become hypertrophic
Diagnosis
The initial diagnosis of leukemia depends mainly on peripheral blood smear, although not necessarily on the peripheral blood smear can be seen in leukemia cells, but the combined clinical symptoms of doubt should be a bone marrow examination. Bone marrow examination to determine the primary diagnosis of acute leukemia, bone marrow extraction process, a side effect is rarely checked, often from the bone marrow in the hip ilium available. Under the skin and periosteum for local anesthesia after a small needle will be inserted into the bone, after connecting the syringe to extract a small amount of bone marrow. The purpose of inspection: one, according to morphological characteristics and the distribution of the number of cells to make a diagnosis: the separation of acute lymphoblastic leukemia and acute myeloid leukemia. Acute lymphoblastic leukemia (ALL) can be so divided L1, L2, L3 three types, 80% of cases of L1, 10% for the L2, L3 are generally expressed as Burkitt cell ALL. The acute myeloid leukemia M1-M7 can be divided into seven types. Second, the use of immunological methods, the acute lymphoblastic leukemia subdivided into B cells and T cells, the most common of common ALL (C-ALL) accounted for 60%, Pre-B ALL accounted for 15%, and other non-T non- B accounted for about 8%, a variety of T-ALL accounted for 15%, B-ALL accounts for only 1-3%. common ALL best prognosis, T cells with poor prognosis. Third, special chemical staining, such as PAS staining, showed positive acute lymphoblastic leukemia response, and myeloperoxidase staining in acute myeloid leukemia showed positive reactions. Fourth, the chromosome: Some specific chromosomal changes in leukemia, can be used as a basis for diagnosis, prognosis or bad judgment, relieve or track and trace residual disease signs, such as CML or ALL a small t (9; 22 ) Philadelphia chromosome, the prognosis is very poor; AM2L with t (8; 21) changes, and t (15; 17) is AM3L (APL) specific chromosomal changes; ALL chromosome number may vary, and prognosis about. Also determine the diagnosis of acute leukemia, the children need to accept the spinal fluid examination to see whether there is infringement of leukemia cells to the central nervous.
Treatment
Like most cancers, like the earlier the treatment the better. The main treatment is chemotherapy, in general, the bone marrow of patients when the disease is 80% to 90% of leukemia cells, normal hematopoietic cells are suppressed and not blood, so the purpose of treatment is to first remove the blood and bone marrow leukemia cells, and guide the patient into complete remission. Complete remission is defined as the proportion of less than bud cells within the bone marrow <5 a="" and="" blood="" cells="" classification="" counts="" grow="" hematopoietic="" let="" normal="" of="" peripheral="" slowly="" span="" stem="" the="" up.="" variety="">Remission, it may not completely clean, so still need to continue the treatment, but if treatment is stopped once at this time, a majority of the patients 1-2 years will relapse.
Acute lymphoblastic leukemia
Acute leukemia different treatment regimens have different designs. Acute lymphoblastic leukemia is the most common childhood cancer, the prognosis is very good. Trends in recent years, tend to be good prognosis (Standard Risk) given a lighter treatment, prognosis is poor (High Risk and Very High Risk) a heavier treatment. Prognostic factors affecting ALL, the most decisive is the treatment itself. Also immune markers, chromosomal changes, the white blood cell count at diagnosis and age, with or without lymphoid leukemia, with or without central nervous system leukemia, also have an effect. Target in the treatment of leukemia remission of the disease to get , and through regular treatment to achieve recovery. Treatment of acute leukemia, about 2-3 years in Taiwan, and its treatment methods generally adopted the "Taiwan Pediatric Oncology Group-TPOG" treatment. Treatment of the above risk factors, divided into high-risk groups (very high risk, VHR), high-risk groups (high risk, HR), standard risk group (standard risk, SR) and other three treatment plan. High-risk groups in Taiwan, accounting for about 27 percent of children with high-risk groups about 28%, while the standard risk group accounted for approximately 45% of the maximum. Overall cure rate of up to 60% of the standard risk group, 80% or even more, is no longer considered terminally ill.
In general, treatment planning guide is divided into remission, consolidation therapy, and then guide the period, spinal fluid injected with cobalt-60 irradiation and maintenance therapy in four stages.
1.BOOT period: to give overall strength of the strong chemical treatment, the goal is to achieve remission (bone marrow leukemia cells less than 5%). General guidance period is about four to five weeks, more than 95% of people will achieve remission.
(2) a period of consolidation: in remission after switching to a different drug combinations to further destruction of residual leukemic cells are resistant in order ruthless.
3 and then guide the period: in the high-risk groups and high-risk treatment plan in order to give a similar medication guide remission once, such treatment can improve the high-risk groups and high risk group cure rate.
4. Maintenance phase: enter the maintenance phase, the treatment becomes more relaxed, the children also mostly used injections and medicine clinic regularly, you can start school, a total period of two to three years.
5 CNS prophylaxis: Children After remission, there are three places to recur: (1) bone marrow (2) central nervous system and (3) the testicles, so the treatment, we need to take into account the central nervous system prophylaxis. In fact, at the time of diagnosis of leukemia, meningeal leukemia cells have been violated or less, but only less than 10% of children with cerebral spinal fluid by conventional diagnosis of central nervous system leukemia. So for all patients with acute leukemia CNS prophylaxis to be given, and the sooner the better. Is currently the early start at boot stage begins CNS prophylaxis given intrathecal injection of three drugs. Period of consolidation and re-boot also have further enhanced to give. High-risk groups and children with the highest risk group in the maintenance period shall be receiving cranial radiation therapy 1800cGy, so that it can better prevent central nervous system leukemia. The central nervous system leukemia relapse prevention therapy rate does not exceed 5%.
Although chemotherapy done quite well, but there are still 20% of the standard group and 40% of children with high-risk groups will relapse, a relapse during treatment but, although there is still opportunity to induce remission, but the chances of recurrence is very high , so for this class pediatric patients should consider hematopoietic stem cell transplantation. But extremely dangerous group of sick children, due to the chemical treatment is not high long-term mitigation opportunities, relapse and more, so if a suitable stem cell donor relatives, consider in first remission after hematopoietic stem cell transplantation is accepted, so to cure The best chance. However, if only unrelated donors, the current concern to the non-high-risk relatives of transplantation, it is recommended to continue chemotherapy or better, unless there is a particularly bad prognostic factors, such as the Philadelphia chromosome were considered only in the first remission, that is to accept unrelated hematopoietic stem cell transplantation.
Acute myelogenous leukemia
Acute myeloid leukemia - a standard guide of chemotherapy treatment regimens of treatment is the use of 3-7, which is Anthracycline three days plus Ara-C seven days, the chance of complete remission was 60-80%, and guide relief normally takes three - 6 weeks, the chemical treatment of severe myelosuppression than ALL many, more complications, there must be well taken care of in order to improve response rates. Although most patients can go into remission, but many sick children will further relapse within one to one and a half, and then make the third induction therapy for patients to get a second remission, and some even get third remission, However, each time will be shorter and shorter periods of remission, these patients will eventually relapse, but also for any treatment failure.
In order to reduce the recurrence of acute myelogenous leukemia, there are several treatment modalities, including the strengthening of post-treatment and bone marrow transplantation. Late intensive treatment, that is, increase the dose of Ara-C, very dense and highly toxic treatment, the patient will often experience similar side effects occurred in the induction period. Clinical results show that, indeed, some of the patients can be a long-term remission. In bone marrow transplantation, is divided into allogeneic hematopoietic stem cell transplantation relatives and autologous hematopoietic stem cell transplantation. Allogeneic hematopoietic stem cell transplantation relative benefits of a higher cure rate (40-50%), a graft-versus-leukemia effect to help kill malignant cells, and lower recurrence rates (10-20%). However, its disadvantage is that there is graft-versus-host reaction (commonly known as exclusion) risk, HLA matching limit (find relatives donors probability <30 a="" aml="" have="" of="" only="" opportunity="" patients="" portion="" receive="" small="" so="" span="" such="" the="" to="" treatment.="">Autologous hematopoietic stem cell transplantation graft benefit is no danger of anti-host reaction, the disadvantage is no graft-versus-leukemia effect, may have leukemia cell contamination, as well as a high recurrence rate. Once the patient is currently considered after complete remission, it is necessary as soon as possible to strengthen style treatment, and the sooner the better to do. As for non-relatives transplant, due to its high risk concerns, the proposed selection of autologous hematopoietic stem cell transplantation or high-dose chemotherapy Sharpening better to wait until the unfortunate relapse, before considering the second remission after receiving unrelated hematopoietic stem cell transplantation.
Conclusion
So far, the Taiwan Pediatric Oncology Group treatment program for acute lymphoblastic leukemia treatment results for the five-year survival rate of 68% (ALL 93SR, 93HR, 97VHR), alone on the standard risk group compared with 82.5% in the treatment of achievements, high-risk group was 65%, the highest risk group was 35%. In acute myeloid leukemia treatment years without an accident survival score of 48% (AML 97), the future outlook is hoping to reduce the cases of death due to infection, studies of trace detection of residual disease, reducing the chance of recurrence, to improve the cure rate of the disease and reduce complications, improve quality of life.
Cause of disease
Still not entirely clear. Many reasons will have a higher chance of causing leukemia, for example: 1. Several congenital diseases, such as: Down syndrome, congenital free nor full, congenital aplastic anemia and other diseases, the chance to get much of leukemia increases. 2 radioactive substances, such as Hiroshima and Nagasaki bombings, making the local People's Congress to increase the risk of leukemia. 3 structural changes within the chromosome genes directly cause cell malignant transformation, and increase the chance of leukemia. 4 Many of the drug or chemical toxins also cause leukemia, such as: Benzene and alkylating agents. But the vast majority are still unexplained.
Classification
According to the clinical course of the disease and leukemia cell types can be divided into four categories: 1. Acute lymphoblastic leukemia (ALL): The most common childhood cancer, accounting for approximately 75% of all childhood leukemia. (2) acute non-lymphocytic leukemia, also known as acute myelogenous leukemia (AML): accounting for about 20% of all childhood leukemia. 3. Chronic myelogenous leukemia (CML), accounting for about 3% of all childhood leukemia. 4 chronic lymphocytic leukemia (CLL): rare in children. The incubation period is generally believed that acute leukemia only about four to eight weeks time after onset if not treated, will soon lead to organ failure, fatigue, anemia, excessive bleeding and infection, survival time of about six months, it is called acute leukemia . While chronic leukemia is the long incubation period, obvious symptoms, if not treated after the onset of the survival time of up to two to three years, so called chronic leukemia.
Clinical
The same as the general cancer, leukemia, often early detection and diagnosis is not easy, sometimes in the case of no symptoms, and occasionally the routine physical examination or blood was found; the most common symptoms are cold like symptoms, such as loss of appetite, fever, fatigue, or bone pain and so on. Therefore, if the phenomenon of unexplained high fever, you should seek your physician, if there is less abnormal, should be vigilant: pale face or lips: Because red blood cells decreased, hemoglobin decreased. easy bleeding, skin bruising: Because thrombocytopenia. unexplained fever: Due to the rapid growth of leukemia cells, destruction, so that metabolic hyperactivity rules. lymphadenopathy: But do not feel pain or tenderness, usually occurs in the neck, armpit or groin. weight loss or growth arrest. bone pain: leukemic cells accumulate in the bone marrow, causing bone marrow expansion, periosteal traction or leukemia cells by a direct violation of the bones, causing pain. This pain especially in the knees and ribs on the bottom of the sternum of the most obvious. organ enlargement: a rapid increase in leukemia cells, violations to the liver, spleen, lymph nodes, thymus or meninges, gonads, kidneys, causing organ enlargement.
gingival hypertrophy: non-lymphocytic leukemia, can still infringe on the gums, the gums become hypertrophic
Diagnosis
The initial diagnosis of leukemia depends mainly on peripheral blood smear, although not necessarily on the peripheral blood smear can be seen in leukemia cells, but the combined clinical symptoms of doubt should be a bone marrow examination. Bone marrow examination to determine the primary diagnosis of acute leukemia, bone marrow extraction process, a side effect is rarely checked, often from the bone marrow in the hip ilium available. Under the skin and periosteum for local anesthesia after a small needle will be inserted into the bone, after connecting the syringe to extract a small amount of bone marrow. The purpose of inspection: one, according to morphological characteristics and the distribution of the number of cells to make a diagnosis: the separation of acute lymphoblastic leukemia and acute myeloid leukemia. Acute lymphoblastic leukemia (ALL) can be so divided L1, L2, L3 three types, 80% of cases of L1, 10% for the L2, L3 are generally expressed as Burkitt cell ALL. The acute myeloid leukemia M1-M7 can be divided into seven types. Second, the use of immunological methods, the acute lymphoblastic leukemia subdivided into B cells and T cells, the most common of common ALL (C-ALL) accounted for 60%, Pre-B ALL accounted for 15%, and other non-T non- B accounted for about 8%, a variety of T-ALL accounted for 15%, B-ALL accounts for only 1-3%. common ALL best prognosis, T cells with poor prognosis. Third, special chemical staining, such as PAS staining, showed positive acute lymphoblastic leukemia response, and myeloperoxidase staining in acute myeloid leukemia showed positive reactions. Fourth, the chromosome: Some specific chromosomal changes in leukemia, can be used as a basis for diagnosis, prognosis or bad judgment, relieve or track and trace residual disease signs, such as CML or ALL a small t (9; 22 ) Philadelphia chromosome, the prognosis is very poor; AM2L with t (8; 21) changes, and t (15; 17) is AM3L (APL) specific chromosomal changes; ALL chromosome number may vary, and prognosis about. Also determine the diagnosis of acute leukemia, the children need to accept the spinal fluid examination to see whether there is infringement of leukemia cells to the central nervous.
Treatment
Like most cancers, like the earlier the treatment the better. The main treatment is chemotherapy, in general, the bone marrow of patients when the disease is 80% to 90% of leukemia cells, normal hematopoietic cells are suppressed and not blood, so the purpose of treatment is to first remove the blood and bone marrow leukemia cells, and guide the patient into complete remission. Complete remission is defined as the proportion of less than bud cells within the bone marrow <5 a="" and="" blood="" cells="" classification="" counts="" grow="" hematopoietic="" let="" normal="" of="" peripheral="" slowly="" span="" stem="" the="" up.="" variety="">Remission, it may not completely clean, so still need to continue the treatment, but if treatment is stopped once at this time, a majority of the patients 1-2 years will relapse.
Acute lymphoblastic leukemia
Acute leukemia different treatment regimens have different designs. Acute lymphoblastic leukemia is the most common childhood cancer, the prognosis is very good. Trends in recent years, tend to be good prognosis (Standard Risk) given a lighter treatment, prognosis is poor (High Risk and Very High Risk) a heavier treatment. Prognostic factors affecting ALL, the most decisive is the treatment itself. Also immune markers, chromosomal changes, the white blood cell count at diagnosis and age, with or without lymphoid leukemia, with or without central nervous system leukemia, also have an effect. Target in the treatment of leukemia remission of the disease to get , and through regular treatment to achieve recovery. Treatment of acute leukemia, about 2-3 years in Taiwan, and its treatment methods generally adopted the "Taiwan Pediatric Oncology Group-TPOG" treatment. Treatment of the above risk factors, divided into high-risk groups (very high risk, VHR), high-risk groups (high risk, HR), standard risk group (standard risk, SR) and other three treatment plan. High-risk groups in Taiwan, accounting for about 27 percent of children with high-risk groups about 28%, while the standard risk group accounted for approximately 45% of the maximum. Overall cure rate of up to 60% of the standard risk group, 80% or even more, is no longer considered terminally ill.
In general, treatment planning guide is divided into remission, consolidation therapy, and then guide the period, spinal fluid injected with cobalt-60 irradiation and maintenance therapy in four stages.
1.BOOT period: to give overall strength of the strong chemical treatment, the goal is to achieve remission (bone marrow leukemia cells less than 5%). General guidance period is about four to five weeks, more than 95% of people will achieve remission.
(2) a period of consolidation: in remission after switching to a different drug combinations to further destruction of residual leukemic cells are resistant in order ruthless.
3 and then guide the period: in the high-risk groups and high-risk treatment plan in order to give a similar medication guide remission once, such treatment can improve the high-risk groups and high risk group cure rate.
4. Maintenance phase: enter the maintenance phase, the treatment becomes more relaxed, the children also mostly used injections and medicine clinic regularly, you can start school, a total period of two to three years.
5 CNS prophylaxis: Children After remission, there are three places to recur: (1) bone marrow (2) central nervous system and (3) the testicles, so the treatment, we need to take into account the central nervous system prophylaxis. In fact, at the time of diagnosis of leukemia, meningeal leukemia cells have been violated or less, but only less than 10% of children with cerebral spinal fluid by conventional diagnosis of central nervous system leukemia. So for all patients with acute leukemia CNS prophylaxis to be given, and the sooner the better. Is currently the early start at boot stage begins CNS prophylaxis given intrathecal injection of three drugs. Period of consolidation and re-boot also have further enhanced to give. High-risk groups and children with the highest risk group in the maintenance period shall be receiving cranial radiation therapy 1800cGy, so that it can better prevent central nervous system leukemia. The central nervous system leukemia relapse prevention therapy rate does not exceed 5%.
Although chemotherapy done quite well, but there are still 20% of the standard group and 40% of children with high-risk groups will relapse, a relapse during treatment but, although there is still opportunity to induce remission, but the chances of recurrence is very high , so for this class pediatric patients should consider hematopoietic stem cell transplantation. But extremely dangerous group of sick children, due to the chemical treatment is not high long-term mitigation opportunities, relapse and more, so if a suitable stem cell donor relatives, consider in first remission after hematopoietic stem cell transplantation is accepted, so to cure The best chance. However, if only unrelated donors, the current concern to the non-high-risk relatives of transplantation, it is recommended to continue chemotherapy or better, unless there is a particularly bad prognostic factors, such as the Philadelphia chromosome were considered only in the first remission, that is to accept unrelated hematopoietic stem cell transplantation.
Acute myelogenous leukemia
Acute myeloid leukemia - a standard guide of chemotherapy treatment regimens of treatment is the use of 3-7, which is Anthracycline three days plus Ara-C seven days, the chance of complete remission was 60-80%, and guide relief normally takes three - 6 weeks, the chemical treatment of severe myelosuppression than ALL many, more complications, there must be well taken care of in order to improve response rates. Although most patients can go into remission, but many sick children will further relapse within one to one and a half, and then make the third induction therapy for patients to get a second remission, and some even get third remission, However, each time will be shorter and shorter periods of remission, these patients will eventually relapse, but also for any treatment failure.
In order to reduce the recurrence of acute myelogenous leukemia, there are several treatment modalities, including the strengthening of post-treatment and bone marrow transplantation. Late intensive treatment, that is, increase the dose of Ara-C, very dense and highly toxic treatment, the patient will often experience similar side effects occurred in the induction period. Clinical results show that, indeed, some of the patients can be a long-term remission. In bone marrow transplantation, is divided into allogeneic hematopoietic stem cell transplantation relatives and autologous hematopoietic stem cell transplantation. Allogeneic hematopoietic stem cell transplantation relative benefits of a higher cure rate (40-50%), a graft-versus-leukemia effect to help kill malignant cells, and lower recurrence rates (10-20%). However, its disadvantage is that there is graft-versus-host reaction (commonly known as exclusion) risk, HLA matching limit (find relatives donors probability <30 a="" aml="" have="" of="" only="" opportunity="" patients="" portion="" receive="" small="" so="" span="" such="" the="" to="" treatment.="">Autologous hematopoietic stem cell transplantation graft benefit is no danger of anti-host reaction, the disadvantage is no graft-versus-leukemia effect, may have leukemia cell contamination, as well as a high recurrence rate. Once the patient is currently considered after complete remission, it is necessary as soon as possible to strengthen style treatment, and the sooner the better to do. As for non-relatives transplant, due to its high risk concerns, the proposed selection of autologous hematopoietic stem cell transplantation or high-dose chemotherapy Sharpening better to wait until the unfortunate relapse, before considering the second remission after receiving unrelated hematopoietic stem cell transplantation.
Conclusion
So far, the Taiwan Pediatric Oncology Group treatment program for acute lymphoblastic leukemia treatment results for the five-year survival rate of 68% (ALL 93SR, 93HR, 97VHR), alone on the standard risk group compared with 82.5% in the treatment of achievements, high-risk group was 65%, the highest risk group was 35%. In acute myeloid leukemia treatment years without an accident survival score of 48% (AML 97), the future outlook is hoping to reduce the cases of death due to infection, studies of trace detection of residual disease, reducing the chance of recurrence, to improve the cure rate of the disease and reduce complications, improve quality of life.
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