Patients present with anemia and bruising due to inadequate production
of erythrocytes and platelets respectively. Poor platelet production is also
associated with bleeding from the gums and nose. An inadequate production
of appropriate leukocytes means that patients suffer repeated infections.
Acute myeloid leukemia requires rapid diagnosis and immediate treatment.
Chemotherapy is effective in bringing many patients into remission
although high dose chemotherapy followed by a stem cell transplant may be
required in some cases. Patients may require platelet transfusions before and
during their treatment and erythropoietin may be given to treat the anemia.
The use of the monoclonal antibody, gemtuzumab ozogamicin, directed at
CD33 proteins present on the surfaces of the leukemic cells may be of some
efficacy.
The prognosis for AML depends on the age at diagnosis. For adults under the
age of 55 years, the five-year survival rate is between 40 and 60%, for those
over 55 years it is unfortunately only 20%.
Chronic lymphocytic leukemia
Chronic lymphocytic leukemia (CLL) is the most common form of leukemia,
affecting mostly those aged over 60 years. It is characterized by the clonal
proliferation of lymphoid stem cells. However, the disease is slow growing
and many patients are asymptomatic in the early stages. Signs and symptoms
include frequent infections, anemia, bleeding and bruising. The spleen and
the lymph nodes in the neck, axillae and groin may be swollen due to the
accumulation of abnormal cells. The cause of CLL is unknown although
in a minority of cases the disease may be familial. A diagnosis of CLL is by
examination of blood and bone marrow. A lymph node biopsy may also be
taken for histological examination. The disease is described as Stage A, B or
C according to the degree of lymph node involvement. Stage C patients have
enlarged lymph nodes in three or more areas and a low erythrocyte and/or
platelet count. Patients with Stage A, with little or no lymph node enlargement
may not need treatment. Patients with Stages B and C may be brought into
remission with chemotherapy. Treatment is usually successful in maintaining
remissions for several years.
Hairy cell leukemia is a rare form of CLL which occurs in people between 40
and 60 years of age. It constitutes 2–5% of leukemias. The leukemic cell is a B
lymphocyte and is characterized by cells with outgrowths or projections which
give the disorder its name (Figure 17.37) although the cause of the pathology
is not known. Patients present with symptoms of breathlessness, weakness,
weight loss and infections. There may also be splenomegaly. Diagnosis is
by examination of blood smears and demonstration of splenomegaly on
examination. Histological examination of a bone marrow specimen is also
undertaken.
Treatment of hairy cell leukemia is by chemotherapy, using cytotoxic drugs.
Interferon A has also been used to treat this disorder. The prognosis for hairy
cell leukemia is good. The leukemia is slow growing and chemotherapy may
only be needed after regular monitoring of cell counts reveals the count of
abnormal cells is rising and if the patient presents with symptoms.
Acute lymphoblastic leukemia
Acute lymphoblastic leukemia (ALL) is a rare disorder that occurs most
frequently in children under the age of 15 years although it does affect around
600 adults annually in the UK, mostly between the ages of 15 and 25 and those
over 75 years of age. The cause of ALL is unknown. The disease is characterized
by a clonal proliferation of a lymphoid stem cell, leading to increased numbers
of lymphoblasts in the blood. As with other leukemias, patients may present
with unusual bleeding of the gums and nose, bruising, anemia, aching
SPECIFIC TYPES OF CANCERSCZhhVg6]bZY!BVjgZZc9Vlhdc!8]g^hHb^i]:YLddY *%.
Figure 17.37An electron micrograph of a single
leukemic cell from a patient with hairy cell
leukemia. Note the numerous extensions of the
plasma membrane that give the condition its
name.