Leukaemia or blood cancer is amongst the ten most common cancers seen in India.
Cancer is an abnormal growth of cells that grow uncontrollably to form a lump or tumour. Cancer cells have two properties that make them dangerous, they can invade into neighbouring tissues, and they can spread to distant areas of the body, forming secondary tumors or metastases.
Blood is made up of plasma and three types of blood cells -
White blood cells are of five types - lymphocytes, granulocytes, monocytes, eosinophils and basophils. Blood cells are produced in the bone marrow in an orderly fashion and only mature cells are released.
What is Leukemia?
Leukemia or blood cancer is a cancer of the white blood cells (WBC). In leukemia a large number of white blood cells are produced in the stem cells of the bone marrow. These immature cells are incapable of normal functions. Cancer starts in the bone marrow but can spread to the blood, lymph nodes, the spleen, liver, central nervous system (the brain and spinal cord), testes (testicles), or other organs.Leukemia can be acute (rapid growing) or chronic (slowly growing). It can further be classified as myelogenous or lymphocytic, depending on which white blood cell type is affected. Thus, the four major types of leukemia are:
What are the signs and symptoms of Leukemia?
In leukemia the marrow is busy producing abnormal white cells and not enough red blood cells are produced resulting in anemia. Patients look pale, feel weak and tired. Reductions in number of healthy platelets cause patients to bruise and bleed easily. Leukemia cells are functionally abnormal, hence the body cannot fight infections and thus patients often get infections and fevers.
Like all blood cells, leukemia cells travel throughout the body. Depending on the number of abnormal cells and where these cells collect, patients with leukemia may have a number of symptoms. In acute leukemia, symptoms appear and get worse quickly. People with this disease visit their doctor because they feel sick.
In acute leukemia, the abnormal cells may collect in the brain or spinal cord (also called the central nervous system or CNS). The result may be headaches, vomiting, confusion, loss of muscle control and seizures. Leukemia cells also can collect in the testicles and cause swelling. Also, some patients develop swelling in the eyes or on the skin. Leukemia affects the digestive tract, kidneys, lungs or other parts of the body.
Common symptoms seen in Leukemia are:
Some of the symptoms mentioned above are quite common in everyday illnesses and do not necessarily indicate cancer. Nevertheless, it is wise to pay heed to these symptoms and seek advice from your doctor. If symptoms persist consult a specialist and get a full check up done. Early detection gives the best chance of cure.
How is Leukemia diagnosed?When we visit a doctor with a problem, the doctor first listens to our complaints in detail and then examines us. In some cases it may be very easy to rule out cancer, using this simple measure but at other times, the doctor recommends tests to be carried out to enable him to confirm or disprove his suspicion.
After history taking and clinical examination, routine examination of the blood, urine, and stool is often the starting point. Depending on circumstances of the case, the doctor may then also recommend other special tests.
The only way to make the diagnosis of cancer is to examine cells or tissues from the suspected lesion under a microscope. Merely establishing the diagnosis of cancer is not enough to select appropriate treatment.Although a simple blood smear examination may reveal that a patient has leukemia, it may not show what type of leukemia it is. To check further for leukemia cells or to decide the type of leukemia, the doctor examines a sample of bone marrow under a microscope. The doctor withdraws the sample by inserting a needle into a large bone (usually the hip) and removing a small amount of liquid bone marrow. This procedure is called bone marrow aspiration. A bone marrow biopsy is performed with a larger needle and removes a small piece of bone and bone marrow. If leukemia cells are found in the bone marrow sample, the doctor orders other tests to find out the extent of the disease. A spinal tap (lumbar puncture) checks for leukemia cells in the fluid that fills the spaces in and around the brain and spinal cord (cerebrospinal fluid). Chest X-rays can reveal signs of disease in the chest.
How is Leukemia treated?
Treatment for leukemia is complex. The treatment depends not only on the type of leukemia, but also on certain features of the leukemia cells, the extent of the disease, and whether the leukemia has been treated before. It also depends on the patient's age, symptoms and general health.
The aim of treatment for acute leukemia is cure. Complete remission means no evidence of cancer. The primary treatment for acute leukemia is chemotherapy. Radiation therapy may be used in certain cases. Presently in some cases bone morrow transplantation is also done.Chronic leukemia patients who do not have symptoms may not require immediate treatment. However, they should have frequent checkups to see how the disease is progressing. Treatment can often control the disease and its symptoms. However, chronic leukemia can seldom be cured.
Chemotherapy is treatment of cancer by drugs. Cancer chemotherapy employs cytotoxic drugs capable of arresting fast cellular growth. Chemotherapy also affects other fast growing normal cells in the body. Anti cancer drugs are normally given by injection into a vein. Chemotherapy is also given into the muscle, under the skin, cerebrospinal fluid (CSF), or taken by mouth. The treatment is given in cyclic form once in 3 to 4 weeks or weekly regimens to allow for adequate recovery of normal tissues and to ensure that cancer cells are killed at the same time. In general, AML treatment will use higher doses of chemotherapy over a shorter period of time, and ALL will take chemotherapy over a longer period of time.
Bone Marrow Transplant
Bone marrow transplantation is a newer type of treatment. First, high doses of chemotherapy with or without radiation therapy are given to destroy all of the bone marrow in the body. Healthy marrow is then taken from another person (a donor) whose tissue is the same as or almost the same as the patient's. The donor may be a twin (the best match), a brother or sister, a parent or another person not related. The healthy marrow from the donor is given to the patient through a needle in a vein, and the marrow replaces the marrow that was destroyed. It is a very complicated and costly procedure. The procedure is reserved for relapsed cases or very aggressive cases.
There are generally four phases of treatment for acute leukemia. The first phase uses chemotherapy to kill as many of the leukemia cells as possible to cause the cancer to go into remission. Once a patient goes into remission and there are no signs of leukemia, a second phase of high-dose chemotherapy is given to attempt to kill any remaining leukemia cells. The third phase is preventive therapy, here high-dose systemic chemotherapy is given to the central nervous system (CNS) to kill any leukemia cells present there, or to prevent the spread of cancer cells to the brain and spinal cord, even if no cancer has been detected there. Radiation therapy to the brain may also be given, in addition to chemotherapy, for this purpose. The fourth phase of treatment uses chemotherapy for 2 years to maintain the remission.
Leukemia and its treatment can cause a number of complications and side effects. Patients need supportive care to prevent or control these problems and to improve their quality of life during treatment. Because leukemia patients get infections very easily, they may receive antibiotics and other drugs to help protect them from infections.
Anemia and bleeding are other problems that often require supportive care. Transfusions of red blood cells may be given to help reduce the shortness of breath and fatigue that anemia can cause. Platelet transfusions can help reduce the risk of serious bleeding. Leukemia and chemotherapy can make the mouth sensitive, easily infected and likely to bleed. Doctors often advise patients to have a complete dental exam before treatment begins.
What will happen after treatment for leukemia?
Every leukemia patient needs close monitoring following treatment. This is referred to as "follow-up". Follow-up is an integral part of cancer treatment and is usually done by physical examination, blood examination, x-ray tests. Cancer patients need life long follow-up. Cancer treatment is never complete theoretically because cancer can occur at the primary site or anywhere else in the body at a later date. For several years after treatment, regular follow-up examination will be very important. The doctors will continue to watch for signs of disease, as well as for short-term and long-term side effects of treatment.
Can leukemia be prevented?
Although many cancers of adults can be prevented by lifestyle changes, which reduce certain risk factors, there is currently no known way to prevent childhood cancers, particularly leukemia.
Are there any tests for early detection of leukemia?At present, there are no special tests recommended for the early detection of leukemia. The best policy for early diagnosis is prompt attention to the signs and symptoms of this disease. Close follow-up is important for children with a known genetic abnormality which might increase their risk of leukemia, children who have had another cancer treated with chemotherapy or combined chemotherapy and radiation therapy and children who have received organ transplants and are taking immune system-suppressing drugs.
What are the chances of cure in acute leukemia?In ALL of children, the long-term survival (cure) is almost in the range of 70-80% (in western countries). In our country it is in the range of 50-55%. Adult ALL-Adults do not fare as well as children. The long-term survival is in the range of 40-45%. AML-the outcome is very dismal for children and adults, the long-term survival in the range of 20%. With high dose chemotherapy & BMT, the maximum long-term survival, which has been achieved is around 35-40%. CML-the only curative treatment is allogenic BMT. Other treatment only increases the survival. CLL-there is no curative treatment, but it is a disease of elderly people, who can maintain good quality of life up to 10 years with proper treatment.