Leukaemia is a cancer of the white blood cells, which are produced by the bone marrow. There are two main types: lymphocytic leukaemia (arising from a type of white blood cell called a lymphocyte) and myeloid leukaemia (arising from an immature type of white blood cell called a myeloid stem cell).
The bone marrow produces two main types of white blood cells: granulocytes and lymphocytes. These work together to fight infection in the body. The fully developed white blood cells circulate around the body in the blood.Many patients with chronic leukemias are asymptomatic. Other leukemias present with splenomegaly, fever, weight loss, malaise, frequent infections, bleeding, thrombosis, or lymphadenopathy. Some chronic leukemias enter a blast phase where the clinical manifestations are similar to the acute leukemias.
Chronic myelogenous leukemia (CML) is characterized by an uncontrolled proliferation of granulocytes. Usually an accompanying proliferation of erythroid cells and megakaryocytes is present. Many patients are asymptomatic but may present with splenomegaly, weight loss, malaise, bleeding, or thrombosis.
Chronic lymphocytic leukemia (CLL) represents a monoclonal expansion of lymphocytes. In 95% of cases, CLL is a predominantly malignant clonal disorder of B lymphocytes. The remainder is secondary to a T-cell clone. The neoplastic cell is a hypoproliferative, immunologically incompetent small lymphocyte. There is primary involvement of the bone marrow and secondary release into the peripheral blood. The recirculating lymphocytes selectively infiltrate the lymph nodes, the spleen, and the liver. The majority of patients are asymptomatic at diagnosis. As the disease progresses, lymphadenopathy, splenomegaly, and hepatomegaly develop. A secondary immune deficiency with hypogammaglobulinemia exists.
Acute lymphocytic leukemia (ALL) is a malignant clonal disorder of the bone marrow lymphopoietic precursor cells. In ALL progressive medullary and extramedullary accumulation of lymphoblasts are present that lack the potential for differentiation and maturation. An inhibition of the normal development of hematopoietic cell elements occurs. The clinical presentation is dominated by progressive weakness and fatigue secondary to anemia, infection secondary to leukopenia, and bleeding secondary to thrombocytopenia. When 50% of the bone marrow is replaced then peripheral blood cytopenias are observed.
Acute myelogenous leukemia (AML) is a group of neoplastic disorders of the hematopoietic precursor cells of the bone marrow. AML is subdivided by the French-American-British system into 6 categories depending on the morphology. AML is not a disorder of rapidly proliferating neoplastic cells. The time for one cell division is prolonged with respect to that of normal bone marrow blast cells. A failure of maturation of the neoplastic cell clone exists. The bone marrow is gradually replaced by blast cells. Therefore, the most important complications are progressive anemia, leukopenia, and thrombocytopenia. Chemotherapy is a treatment of an illness or disease with a chemical substance, e.g. in the treatment of cancer.
Treatment for Leukaemia :
The first treatment for all types of leukaemia is usually Chemotherapy (treatment of an illness or disease with a chemical substance, e.g. in the treatment of cancer). This is a powerful drug treatment that kills the leukaemia cells. Chemotherapy drugs can be given in the form of tablets or injected directly into a Veins (Intravenous or IV).
Sometimes they are injected directly into the fluid around the brain and spinal cord, to destroy any cells that are in the nervous system. How you receive the drugs depends on whether your leukaemia is chronic or acute, and what stage of treatment you are at. The first stage of chemotherapy is called induction. It consists of several sessions each lasting a few days, with rest periods of several weeks in between. Induction is a period of intensive therapy and usually manages to kill most of the cancerous cells.
Induction is usually followed by one or two further cycles of treatment. This is the intensification or consolidation stage, and aims to increase the chances of a cure by continuing to destroy leukaemia cells. In both induction and consolidation, chemotherapy drugs are usually injected directly into a vein.
Finally, there is a stage of maintenance therapy. This is less intensive and the drugs are given as tablets. It can continue for another two years and is designed to kill any remaining leukaemia cells. Steroid drugs are sometimes given at the same time as chemotherapy, to help destroy the leukaemia cells.
2. Bone marrow transplant
Bone marrow is the soft, spongy tissue in the centre of bones that produces blood cells. Bone marrow transplant is also used to treat leukaemia. It can be used in conjunction with chemotherapy to greatly improve the patient’s chances of recovery. It provides the patient with a new set of parent-forming cells(cells that are at an early stage of development, so they still have the ability to turn into any type of cell in the bodystem cells, we called as stem cells ) that can produce healthy new red and white blood cells.
Before a transplant takes place, the patient’s abnormal bone marrow is destroyed through total body radiation, in combination with the drug cyclophosphamide. Bone marrow transplant requires a matched donor (whose cells are compatible with the Leukaemia patient) to donate some of their stem cells. Matched donors may be found among close relatives such as brothers or sisters, or can be from an unrelated donor.
In certain forms of leukaemia it is even possible to take marrow from a person in remission, store it, expose the person to heavy radiation and then replace the original sample to start up the marrow function again. The transplant involves sucking marrow out of the pelvis or breastbone of the donor and injecting it into one of the recipient’s veins. The bloodstream carries the marrow cells to the recipient’s bone marrow, where they settle and begin to produce new cell lines (clones) Certain treatments for leukaemia can have an effect on your fertility (your ability to have children).
Leukaemia’s drugs have more effect on fertility than others; radiation prior to bone marrow transplant is very likely to cause infertility, but patients treated with certain chemotherapy drugs will still be able to have children. If you may want to have children in the future, you should discuss options with your hospital consultant prior to treatment, because it is sometimes possible to remove sperm or eggs from your body and store them for future use.