At BCCH we are fortunate to have a team of oncology pharmacists who presented an intro to peds oncology ADS, with a focus on childhood leukemias and tumour lysis syndrome. Please see below for my notes from this ADS as well as the pre-readings:
Leukemia is the most frequent malignancy that occurs during childhood and comprises approximately 30% of all childhood cancers.
|Leukemia classification||% of childhood leukemias|
|Acute lymphocytic (ALL)||80|
|Acute nonlymphocytic leukemia (ANLL)||17|
|Chronic myelogenous leukemia(CML)||3|
|Chronic lymphocytic leukemia (CLL)||Virtually none|
Clinical Presentation and Diagnosis
- The extra-medullary organs most frequently experiencing leukemia infiltration are the liver, spleen, and lymph nodes; many, but not all, affected children initially present with enlargement of these organs detectable on physical examination.
- Other potential leukemia infiltration sites are the CNS and testes
- Leukemia has the potential to involve any body organ, including skin, kidney, lung, pleura, pericardium, eye, breast, ovaries, and gastrointestinal tract.
- Leukemia expansion within the bone marrow may produce signs and symptoms of bone involvement. ~ 25% of children who have newly diagnosed leukemia present with a complaint of severe bone pain
- Leukemia proliferation within the bone marrow results in decreased production of normal white blood cells, red blood cells, and platelets. Malignant leukemia blast cells are frequently, but not always, observed circulating in the blood. A bone marrow examination is essential for a conclusive diagnosis of leukemia, and to assist in identifying specific subtypes of leukemia. Many initial signs and symptoms of leukemia are related to decreased production of normal blood cells.
- The major life-threatening complication in a child who has acute leukemia remains overwhelming infection, often sepsis or severe pneumonia. The risk of sepsis can be correlated directly with the severity of neutropenia; other alterations of host immunity produced by leukemia also contribute to infection risk.
|Leukemia Abnormality||Clinical Signs, Symptoms, or Complications|
|Anemia||Pallor, fatigue, decreased appetite; congestive heart failure with extremely severe anemia|
|Neutropenia||Fever; risk of overwhelming infection increases with severity of neutropenia|
|Thrombocytopenia||Petechiae, ecchymoses, mucosal and other bleeding|
|Coagulation factor deficiencies||Increased bleeding; disseminated intravascular coagulation with severe factor deficiencies occurs frequently in the acute promyelocytic subset of acute nonlymphocytic leukemia|
|Leukemia in bone||Bone pain|
Treatment and Prognosis
- Leukemia chemotherapy regimens are generally divided into three phases: induction, intensification, and maintenance. The goals of induction therapy are to achieve a complete remission of leukemia and to optimize chances that a remission will be maintained. Children who have ALL and are treated with current chemotherapy regimens have a greater than 95% probability of achieving a complete remission within 4 weeks!!
- Advances in supportive care and management of leukemia complications also have contributed to better leukemia remission rates and survival. The availability of blood components prepared with minimal risk of transfusion-induced infection has been an important adjunct in the treatment of a child who has newly diagnosed leukemia.
- Platelet transfusion therapy has reduced the risk of mortality in children who have leukemia and severe bleeding manifestations.
- Effective broad-spectrum antibiotic coverage in the neutropenic febrile child also has helped to reduce morbidity and mortality from infections.
- Adequate nutrition support also has been essential, particularly when children who have leukemia require intense therapy such as that used in hematopoietic stem cell transplant regimens.
- After completion of therapy, children are at varying risk for both leukemia recurrence and long-term treatment complications, depending on the type of leukemia and treatments employed. Some children who have ALL may develop leukemia relapse after initial therapy completion, including recurrences in the extramedullary CNS or testicular sites when the bone marrow remains in remission. Avascular necrosis of the femoral head, which presents as hip pain, can be a complication of therapy, presumably because of effects of corticosteroids.
- The risk of treatment-related sequelae is related to the type and intensity of therapies employed, with children who received radiation therapy or intensive therapy for relapsed leukemia more likely to develop long-term complications.
- The prevalence of second malignancies occurring within the first 25 years after treatment for childhood leukemia is at least 3%, with the CNS being the most frequent site of involvement.