leukemia(CML)is a cancer of the blood
and bone marrow, occurring primarily in adults aged over 50 years with a slight male predominance. Although
its causes are not well known, the disease is favored by exposure to benzene and ionizing radiation.CML represents 15-20 % of adult leukemia.Being associated with a genetic abnormality, chronic myeloid leukemia is
characterized by excessive production of white blood cells or overgrowth of myeloid cells in the bone marrow. In order
words, the cancer begins by causing abnormal growth in the blood-forming tissue of the bone marrow.
Chronic myeloid leukemia is one of four
major myeloproliferative disorders:
Polycythemia vera – too
many red blood cells in the bone narrow
Leukemia – see above
Essential thrombocythemia - increased number
Primary myelofibrosis or
myeloid splenomegaly – malignant tumor
tissues in the body
Symptoms of Chronic Myeloid
The onset of chronic myeloid leukemia is
insidious and some cases are discovered incidentally during a routine blood count in apparently healthy
1) General Symptoms - The condition
tends to be asymptomatic at the beginning. Fever is absent or reduced; yet the
patient experiences fatigue, sweating, loss of appetite, sometimes dyspnea. Some people may initially be
suspected of hyperthyroidism. Diagnosis may also reveal an increased basal metabolism, which can be a sign of
complications or the result of leukemic proliferation.
2) Symptoms related to abnormal blood
counts – Anemia and tendency to infections are generally rare during the first month of evolution
because the white blood cells are functional. More often there is a tendency to
hemorrhage [bleeding gum, epistaxis, purpura (red or purple
discolorations on the skin)], bleeding during dental
related to the development of leukemic tissue:
a) The spleen is enlarged
(splenomegaly), and sometimes reaches the left iliac fossa. It is hard and painless unless there is the
perisplenitis (inflammation of
the tissues surrounding the spleen). In this case you may hear
auscultation. Splenomegaly is often manifested and can be visible in the epigastrium or left upper
quadrant. Sometimes severe pain can occur in patients who suffer from perisplenitis.
b) Lymph nodes are not enlarged in the majority of cases. But when lymphadenopathy (enlargement or infection of the lymph
nodes) is present the
condition is generally considered serious.
c) The liver is often slightly enlarged, at least, at the end.
d) The bones can be spontaneously painful, or when under
Treatment of Chronic
With very few exceptions,
chronic myeloid leukemia remains incurable. Before the recent coming of targeted therapies, the median survival with conventional
drugs like Misulban and Hydrea was 5 years, and the outcome was always fatal by transformation into acute
leukemia. The treatment aims to delay the maximum acute transformation and control leukocytosis
to prevent complications.
A cure is possible
after allogenic bone marrowtransplant from either family (siblings) or non-family donor for patients less than 50 years.
Patients receive much longer remissions when treated with Interferon alpha. Several better chemotherapy drugs
are also underway. Since the late 1990s, there is an emergence of new chemo drugs on the market: Gleevec,
Sprycel or Tasigna, and others. Regarding Gleevec (Imatinib), it can radically transform the
prognosis. This treatment recently puts on the market makes it possible to target cancer cells:
chromosomal abnormality of CML causes a translocation between chromosomes 9 and 22 which allows the formation
of a protein that has an aberrant tyrosine kinase activity…
It is this activity that
“instructs “cancer cells to grow out of control and prevents them from undergoing apoptosis (programmed cell
death). Imatinib has an inhibitory action on the
tyrosine kinase activity of Bcr-Abl (Bcr-Abltyrosine-kinase
inhibitor) because it will bind to
the binding site of adenosine triphosphate of the protein, preventing it from functioning properly to
facilitate cancerous proliferation. It is a target therapy medication and now used in 1st line of chronic
myeloid leukemia treatment.