Leukemia is cancer of the blood. It
is common cancer, that affects people of all ages. This
article is a brief account of this dangerous but
No. Leukemia can be classified into acute and chronic. The onset of acute leukemia is rapid and if untreated death occurs within 3 to 6 months. Chronic leukemia, on the other hand, sets in slowly and death, even in untreated patients, occurs in 2 to 10 years or sometimes later.
There are many subtypes of
each of these 4 major varieties and the outlook is highly
Another form of blood cancer is referred to as multiple myeloma.
Leukemia is diagnosed on the basis of its clinical features and laboratory tests.
Clinical features. Depending on the
type of leukemia presentation is highly variable and
ranges from fever, weakness, and loss of weight. In acute
leukemia there may be bleeding into skin or bleeding from
nose, mouth or intestine. Chronic leukemia may, on the
other hand, present with dragging sensation or a mass in
the abdomen due to enlargement of spleen.
Laboratory features: Leukemia may be detected through a routine blood test. In leukemia the precursors (parent cells) of the blood cells, that in healthy state remain in the bone marrow, may get released into blood. The white cell counts are often markedly increased. The diagnosis rests on finding that most of these cells are immature (i.e. they resemble parent cells) and not mature cells. Some immature cells are also found in blood in many non-malignant conditions especially infections. Therefore, presence of immature cells in blood is not a definite evidence of leukemia.
In some cases immature cells do not
appear in the peripheral blood and examination of bone
marrow is required to make a diagnosis. Bone marrow
examination is often necessary to determine exact type of
leukemia by special tests and extent of disease. The bone
marrow shows proliferation (increase) in primitive
(parent) cells of blood. These primitive cells differ
from normal cells and can be identified by routine
techniques or by special procedures.
Special tests consist of (i) cytochemical stains (ii) cytogenetic studies to determine chromosomal pattern and (iii) immunochemistry/immunophenotyping. These help in clearly defining the precise nature of the cell from which the cancer arises. Some other tests such as genetic markers can also be studied but are generally not required. The special tests are performed in specialised laboratories as they are expensive and need expertise to interpret results.
Special tests are necessary because
the treatment and prognosis markedly differ with the type
and subtype of leukemia. For example for most types of
acute lymphocytic leukemia (ALL), chemotherapy is the
treatment of choice while for some types the preferred
treatment is bone marrow transplantation.
No. The prognosis of leukemia has markedly changed and many forms of leukemia are curable? Somewhat paradoxically, the cure rate in acute leukemia is higher than in most forms of chronic leukemias. In one form of chronic leukemia referred to as "hairy cell leukemia' the prognosis is good.
The treatment is highly specialized and for many patients requires hospitalization at suitable intervals. The primary modality is courses of combination chemotherapy i.e. administration of drugs by parenterally (by injection) or orally. These medicines kill not only cancer cells but also normal blood cells. Therefore, there is further fall in hemoglobin, white cells and platelets. The ill effects are controlled through (i) regulation of dose of anti-cancer drugs, (ii) replacement (transfusion) of specific products, (iii) administration of antibiotics and (iv) barrier nursing. The effects include fever (due to infections), diarrhea, bleeding, hair loss and kidney and liver damage. Many other serious complications can occur requiring expert management. Generally the courses of therapy are referred to as 'Remission induction', 'Consolidation' and 'Maintenance'. The courses are spread over about 2 years.
Some patients require drugs that induce immune response against leukemic cells. Other treatment modalities include radiotherapy and bone marrow transplantation. In India the bone marrow transplantation facilities are now available at (i) Christian Medical College Hospital, Vellore, Tamil Nadu, (ii) Tata Memorial Centre, Mumbai, Apollo Hospital, Chennai and All India Institute of Medical Sciences, New Delhi.
Psychological support for the patient and the family is required.
If one therapeutic regimen fails or the disease relapses, many patients respond to alternate regimens of drugs.
Several groups are conducting intensive research to understand the nature of cancer and find new therapies. Every year new medicines are introduced which are more effective and have fewer side effects. Drugs are being attached to molecules that will reach the cancer cells and spare the normal cells. Alternatives to bone marrow transplantation are also emerging. It is hoped that in the next two to three years several new modalities will be commercially available.
Swaroop K Sood, , MD (AIIMS), is the head of Pathology
services at Sir Ganga Ram Hospital. Formerly Associate
Professor of Pathology at the All India Institute of
Medical Sciences, and later Professor and Head of
Pathology, University College of Medical Sciences, Dr
Sood has a special interest in Hematology. He has had an
active academic career and has published several papers
in national and international journals.
Last revised: May 12, 2000