Acute leukemia
Acute leukemia: Excerpt from Professional Guide to Diseases (Eighth Edition)
Acute leukemia is a malignant proliferation of white blood cell (WBC) precursors (blasts) in bone marrow or lymph tissue and their accumulation in peripheral blood, bone marrow, and body tissues. Its most common forms are acute lymphoblastic (lymphocytic) leukemia (ALL), an abnormal growth of lymphocyte precursors (lymphoblasts); acute myeloblastic (myelogenous) leukemia (AML), the rapid accumulation of myeloid precursors (myeloblasts); and acute monoblastic (monocytic) leukemia, or Schilling's type, a marked increase in monocyte precursors (monoblasts). Other variants include acute myelomonocytic leukemia and acute erythroleukemia.
Untreated, acute leukemia is invariably fatal, usually because of complications that result from leukemic cell infiltration of bone marrow or vital organs. With treatment, prognosis varies. In ALL, treatment induces remissions in 90% of children (average survival time: 5 years) and in 65% of adults (average survival time: 1 to 2 years). Children between ages 2 and 8 have the best survival rate — about 50% — with intensive therapy. In AML, the average survival time is only 1 year after diagnosis, even with aggressive treatment. In acute monoblastic leukemia, treatment induces remissions lasting 2 to 10 months in 50% of children; adults survive only about 1 year after diagnosis, even with treatment.
Causes and incidence
Research on predisposing factors isn't conclusive but points to some combination of viruses (viral remnants have been found in leukemic cells), genetic and immunologic factors, and exposure to radiation and certain chemicals. (See Predisposing factors to acute leukemia.)
Pathogenesis isn't clearly understood, but immature, nonfunctioning WBCs appear to accumulate first in the tissue where they originate (lymphocytes in lymph tissue, granulocytes in bone marrow). These immature WBCs then spill into the bloodstream and from there infiltrate other tissues, eventually causing organ malfunction because of encroachment or hemorrhage.
Acute leukemia is more common in males than in females, in whites (especially people of Jewish descent), in children (between ages 2 and 5; 80% of all leukemias in this age-group are ALL), and in people who live in urban and industrialized areas. Acute leukemia accounts for 20% of all adult leukemias. Among children, however, it's the most common form of cancer. Incidence is 6 out of every 100,000 people.
Signs and symptoms
Signs of acute leukemia are sudden onset of high fever accompanied by thrombocytopenia and abnormal bleeding, such as nosebleeds, gingival bleeding, purpura, ecchymoses, petechiae, easy bruising after minor trauma, and prolonged menses. Nonspecific signs and symptoms, such as low-grade fever, weakness, and lassitude, may persist for days or months before visible symptoms appear. Other insidious signs and symptoms include pallor, chills, and recurrent infections. In addition, ALL, AML, and acute monoblastic leukemia may cause dyspnea, anemia, fatigue, malaise, tachycardia, palpitations, systolic ejection murmur, and abdominal or bone pain. When leukemic cells cross the blood-brain barrier and thereby escape the effects of systemic chemotherapy, the patient may develop meningeal leukemia (confusion, lethargy, headache).
Diagnosis
CONFIRMING DIAGNOSIS Typical clinical findings and bone marrow aspirate showing a proliferation of immature WBCs confirm acute leukemia.
A bone marrow biopsy, usually of the posterior superior iliac spine, is part of the diagnostic workup. Blood counts show thrombocytopenia and neutropenia. Differential leukocyte count determines cell type. Lumbar puncture detects meningeal involvement.
Treatment
Systemic chemotherapy aims to eradicate leukemic cells and induce remission (less than 5% of blast cells in the marrow and peripheral blood are normal). Chemo-therapy varies:
❑Meningeal leukemia — intrathecal instillation of methotrexate or cytarabine with cranial radiation.
❑ALL — vincristine, prednisone, high-dose cytarabine, l-asparaginase, AMSA, and daunorubicin. Because there's a 40% risk of meningeal leukemia in ALL, intrathecal methotrexate or cytarabine is given. Radiation therapy is given for testicular infiltration.
❑AML — a combination of I.V. daunorubicin and cytarabine or, if these fail to induce remission, a combination of cyclophosphamide, vincristine, prednisone, or methotrexate; high-dose cytarabine alone or with other drugs; amsacrine; etoposide; and 5-azacytidine and mitoxantrone. A subtype of AML called acute promyelocytic leukemia (APL) is treated with all-transretinoic acid (ATRA), which causes leukemic cells to mature into normal WBCs. ATRA has increased the cure rate of this type of AML. Arsenic trioxide has been approved for patients with APL who have failed ATRA as the usual chemotherapy.
❑Acute monoblastic leukemia — cytarabine and thioguanine with daunorubicin or doxorubicin.
Bone marrow transplant or a stem-cell transplant may be possible. Treatment also may include antibiotic, antifungal, and antiviral drugs and granulocyte injections to control infection and transfusions of platelets to prevent bleeding and of red blood cells to prevent anemia.
Special considerations
The care plan for the leukemic patient should emphasize comfort, minimize the adverse effects of chemotherapy, promote preservation of veins, manage complications, and provide teaching and psychological support.
PEDIATRIC TIP Because many of these patients are children, be especially sensitive to their emotional needs and those of their families.
Before treatment:
❑Explain the disease course, treatment, and adverse effects.
❑Teach the patient and his family how to recognize infection (fever, chills, cough, sore throat) and abnormal bleeding (bruising, petechiae) and how to stop such bleeding (pressure, ice to area).
❑Promote good nutrition. Explain that chemotherapy may cause weight loss and anorexia, so encourage the patient to eat and drink high-calorie, high-protein foods and beverages. However, chemotherapy and adjunctive prednisone may cause weight gain, so dietary counseling and teaching are helpful.
❑Help establish an appropriate rehabilitation program for the patient during remission.
Plan meticulous supportive care:
❑Watch for symptoms of meningeal leukemia (confusion, lethargy, headache). If these occur, know how to manage care after intrathecal chemotherapy. After such instillation, place the patient in Trendelenburg's position for 30 minutes. Force fluids, and keep the patient in the supine position for 4 to 6 hours. Check the lumbar puncture site often for bleeding. If the patient receives cranial radiation, teach him about potential adverse effects, and do what you can to minimize them.
❑Prevent hyperuricemia, a possible result of rapid chemotherapy-induced leukemic cell lysis. Encourage fluids to about 67 ½ oz (2,000 ml) daily, and give acetazolamide, sodium bicarbonate tablets, and allopurinol. Check urine pH often — it should be above 7.5. Watch for rash or other hypersensitivity reaction to allopurinol.
❑Watch for early signs of cardiotoxicity such as arrhythmias and signs of heart failure if the patient receives daunorubicin or doxorubicin.
❑Control infection by placing the patient in a private room and instituting neutropenic precautions. Coordinate patient care so the leukemic patient doesn't come in contact with staff who also care for patients with infections or infectious diseases. Avoid using indwelling urinary catheters and giving I.M. injections because they provide an avenue for infection. Screen staff and visitors for contagious diseases, and watch for and report any signs of infection.
❑Provide thorough skin care by keeping the patient's skin and perianal area clean, applying mild lotions or creams to keep skin from drying and cracking, and thoroughly cleaning skin before all invasive skin procedures. Change I.V. tubing according to your facility's policy. Use strict sterile technique and a metal scalp vein needle (metal butterfly needle) when starting I.V. therapy. If the patient receives total parenteral nutrition, give scrupulous subclavian catheter care.
❑Monitor temperature every 4 hours; patients with fever over 101° F (38.3° C) and decreased WBC counts should receive prompt antibiotic therapy.
❑Watch for bleeding; if it occurs, apply ice compresses and pressure, and elevate the extremity. Avoid giving I.M. injections, aspirin, and aspirin-containing drugs. Also avoid taking rectal temperatures, giving rectal suppositories, and doing digital examinations.
❑Prevent constipation by providing adequate hydration, a high-residue diet, stool softeners, and mild laxatives and by encouraging walking.
❑Control mouth ulceration by checking often for obvious ulcers and gum swelling and by providing frequent mouth care and saline rinses. Tell the patient to use a soft toothbrush and to avoid hot, spicy foods and overuse of commercial mouthwashes.
❑Check the rectal area daily for induration, swelling, erythema, skin discolora-tion, or drainage.
❑Provide psychological support by establishing a trusting relationship to promote communication. Allow the patient and his family to verbalize their anger and depression. Let the family participate in his care as much as possible.
❑Minimize stress by providing a calm, quiet atmosphere that's conducive to rest and relaxation.
PEDIATRIC TIP For children, be flexible with patient care and visiting hours to promote maximum interaction with family and friends and to allow time for schoolwork and play.
❑For those patients who are refractory to chemotherapy and in the terminal phase of the disease, supportive nursing care is directed to comfort; management of pain, fever, and bleeding; and patient and family support. Provide the opportunity for religious counseling. Discuss the option of home or hospice care.
Chronic granulocytic leukemia
Chronic granulocytic leukemia (CGL), also known as chronic myelogenous leukemia and chronic myelocytic leukemia, is characterized by the abnormal overgrowth of granulocytic precursors (myeloblasts, promyelocytes, metamyelocytes, and myelocytes) in bone marrow, peripheral blood, and body tissues.
CGL's clinical course proceeds in two distinct phases: the insidious chronic phase, with anemia and bleeding abnormalities and, eventually, the acute phase (blastic crisis), in which myeloblasts, the most primitive granulocytic precursors, proliferate rapidly. This disease is invariably fatal. Average survival time is 3 to 4 years after onset of the chronic phase and 3 to 6 months after onset of the acute phase.
Causes and incidence
About 95% of patients with CGL have the Philadelphia, or Ph1, chromosome, an abnormality discovered in 1960 in which the long arm of chromosome 22 is translocated, usually to chromosome 9. Radiation and carcinogenic chemicals may induce this chromosome abnormality. Myeloproliferative diseases also seem to increase the incidence of CGL, and some clinicians suspect that an unidentified virus causes this disease.
CGL is most common in young and middle-aged adults and is slightly more common in men than in women; it's rare in children. In the United States, approximately 4,300 cases of CGL develop annually, accounting for roughly 20% of all leu-kemias.
Signs and symptoms
Typically, CGL induces the following clinical effects:
❑anemia (fatigue, weakness, decreased exercise tolerance, pallor, dyspnea, tachycardia, and headache)
❑ thrombocytopenia, with resulting bleeding and clotting disorders (retinal hemorrhage, ecchymoses, hematuria, melena, bleeding gums, nosebleeds, and easy bruising)
❑ hepatosplenomegaly, with abdominal discomfort and pain in splenic infarction from leukemic cell infiltration.
Other signs and symptoms include sternal and rib tenderness from leukemic infiltrations of the periosteum; low-grade fever; weight loss; anorexia; renal calculi or gouty arthritis from increased uric acid excretion; occasionally, prolonged infection and ankle edema; and, rarely, priapism and vascular insufficiency.
Diagnosis
CONFIRMING DIAGNOSIS In patients with typical clinical changes, chromosomal analysis of peripheral blood or bone marrow showing the Philadelphia chromosome and low leukocyte alkaline phosphatase levels confirms CGL.
Other relevant laboratory results show:
❑white blood cell abnormalities — leukocytosis (leukocytes more than 50,000/µl, ranging as high as 250,000/µl), occasional leukopenia (leukocytes less than 5,000/µl), neutropenia (neutrophils less than 1,500/µl) despite high leukocyte count, and increased circulating myeloblasts
❑hemoglobin — commonly below 10 g/dl
❑ hematocrit — low (less than 30%)
❑ platelets — thrombocytosis (more than 1 million/µl) is common
❑ serum uric acid — possibly more than 8 mg/dl
❑ bone marrow aspirate or biopsy — hypercellular; characteristically shows bone marrow infiltration by significantly increased number of myeloid elements (biopsy is done only if aspirate is dry); in the acute phase, myeloblasts predominate
❑ computed tomography scan — may identify the organs affected by leukemia.
Treatment
Aggressive chemotherapy has so far failed to produce remission in CGL. Consequently, the goal of treatment in the chronic phase is to control leukocytosis and thrombocytosis. The most commonly used oral agents are busulfan and hydroxyurea. Interferon-alfa–based therapy has been used as well. However, the development and introduction of imatinib mesylate, a tyrosine kinase inhibitor that has shown significant long-term effectiveness, has remarkably changed CGL treatment.
Aspirin is commonly given to prevent stroke if the patient's platelet count is more than 1 million/µl.
Ancillary CGL treatments include:
❑local splenic radiation or splenectomy to increase platelet count and decrease adverse effects related to splenomegaly
❑leukapheresis (selective leukocyte removal) to reduce leukocyte count
❑allopurinol to prevent secondary hyperuricemia or colchicine to relieve gout caused by elevated serum uric acid levels
❑prompt treatment of infections that may result from chemotherapy-induced bone marrow suppression.
During the acute phase of CGL, lymphoblastic or myeloblastic leukemia may develop. Treatment is similar to that for acute lymphoblastic leukemia. Remission, if achieved, is commonly short lived. Bone marrow transplant may produce long asymptomatic periods in the early phase of illness but has been less successful in the accelerated phase. Despite vigorous treatment, CGL can progress after onset of the acute phase.
Special considerations
In patients with CGL, meticulous supportive care, psychological support, and careful patient teaching help make the most of remissions and minimize complications. When the disease is diagnosed, be prepared to repeat and reinforce the physician's explanation of the disease and its treatment to the patient and his family.
Throughout the chronic phase of CGL when the patient is hospitalized:
❑If the patient has persistent anemia, plan your care to help avoid exhausting the patient. Schedule laboratory tests and physical care with frequent rest periods in between, and assist the patient with walking, if necessary. Regularly check the patient's skin and mucous membranes for pallor, petechiae, and bruising.
❑To minimize bleeding, suggest a soft-bristle toothbrush, an electric razor, and other safety precautions.
❑To minimize the abdominal discomfort of splenomegaly, provide small, frequent meals. For the same reason, prevent constipation with a stool softener or laxative, as needed. Ask the dietary department to provide a high-bulk diet, and maintain adequate fluid intake.
❑To prevent atelectasis, stress the need for coughing and deep-breathing exercises.
Because many patients with CGL receive outpatient chemotherapy throughout the chronic phase, sound patient teaching is essential:
❑Explain expected adverse effects of chemotherapy: pay particular attention to dangerous adverse effects such as bone marrow suppression.
❑Tell the patient to watch for and immediately report signs and symptoms of infection: any fever over 100° F (37.8° C), chills, redness or swelling, sore throat, and cough.
❑Instruct the patient to watch for signs of thrombocytopenia, to immediately apply ice and pressure to any external bleeding site, and to avoid aspirin and aspirin-containing compounds because of the risk of increased bleeding.
❑Emphasize the importance of adequate rest to minimize the fatigue of anemia. To minimize the toxic effects of chemotherapy, stress the importance of a high-calorie, high-protein diet.
For more information on treatment during the acute phase, see “Acute leukemia” on page 144.
Pictures
Book Source Details
- Book Title: Professional Guide to Diseases (Eighth Edition)
- Author(s): Springhouse
- Year of Publication: 2005
- Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2005 Lippincott Williams & Wilkins.
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