Leukemia According to the Cancer Book from the American Cancer Society, Leukemia is a cancer of the blood. It was first identified as a new disease in around 1830 in Germany. The scientific term, "leukemia," comes from the Greek words that mean "white blood.
" The disease is described as a cancerous disorder not just of the blood itself, but also of the organs that produce the blood cells in the body. The organs are mainly the bone marrow and the lymph system, where normal red and white cells, lymph cells, and platelets grow before entering the bloodstream. Normal cells usually go through the same process but with differences in rate, number, and function ability. With the disease, the bone marrow will not be able to produce the sufficient levels of red blood cells and platelets, while the white blood cells will produce so rapidly that the cells will not become mature enough to fight off infections.As the disease progresses, the whole blood system will become useless due to the vast amount of immature cells produced. If a person with the disease is not treated, there will be excessive bleeding and infections until the body reaches the point where it becomes defenseless.
The body will make minor injury or infection very serious. Leukemia itself does not always kill people. Instead, people die from infections such as small virus or bacteria because there are not enough normal white blood cells in the body. Also, people could die form internal bleeding, which could have been prevented by the platelets. Leukemia appears more commonly in adults then children.A survey in 1989 stated that approximately 25,000 new cases of the disease are diagnosed annually in the United States, 22,500 of them are adults and only 2,500 are children.
It also shows that men are affected by leukemia 30 percent more frequently than women. Ten years ago, about 17,000 people die from the disease each year. Many of the advanced industrial nations have increased the study of leukemia since the 1930s. In the Personal Health Report, the information stated that there are two major types are leukemia: "Lymphocytic leukemia which involves lymphoid committed cells which form and mature in the lymphatic system, and granulocytic leukemia which affects myeloid committed cells which form and mature in the bone marrow" (355). Each of the two types can occur in either acute or chronic form.
Acute form usually affects young cells that are still in the process of growing; they can divide very quickly and may speed the progress of the disease. The chronic form involves the mature cells that reproduce in a low rate or the ones that have stopped dividing. According to the Home Medical Guide, acute lymphocytic leukemia is most commonly seen in children between the age of two and nine. In this type of leukemia, males are affected more frequently than females. Before treatment was available, the average survival rate is only 5 to 6 months.As treatment developed, more then 95 percent of all children are putted into complete remission.
Both adult and childhood disease can be cured in around four years, and the therapy can be discontinued. Chronic lymphocytic leukemia is the most common form of cancer found in the industrialized countries. Like acute lymphocytic, it occurs more frequently in males then in females. The patients that are affected by chronic lymphocytic leukemia are usually older then any other patients with different types of leukemia.The cause of this specific type of disease is still unknown: Strong evidence points to problems of function and control in the immune system diagnosis is very often discovered by accident in the course of routine blood testing for other medical reasons, since fully 25 to 30 percent of newly diagnosed patients have no symptoms.
.the degree of bone marrow infiltration by small lymphocytes is a much more accurate sign of degree of disease. (452) According to the Home Medical Guide, acute granulocytic leukemia usually occur in older ages: "The typical patient is thirty to sixty years old, the frequency of the disease increasing with age. The natural course of untreated this disease leads to an average survival of only two to five months" (451). With chemotherapy, the survival rate can be lengthened to about 5 years.
Around 75 percent of the patient can be cured with a complete remission.This type of leukemia can cause heart attacks and strokes by blocking the arteries: "It is treated by removing large numbers of white cells from the patient's blood and increasing the intensity of the chemotherapy"(453). Over 50 percent of the patients are found with abnormalities in the chromosomes: "Evidence strongly suggests that each patient's individual chromosomal makeup has a strong direct bearing on prognosis" (453). Patients that have abnormal genes in their leukemia cells usually have the disease. Chronic granulocytic leukemia occurs in people with ages forty to sixty. The disease starts out very slowly.
Patient will not notice anything wrong until after three to six months.Many organs such as the liver, spleen and lymph nodes will enlarge in over half of the patients. The study of chromosomes are important in this type of leukemia: "The so-called Philadelphia chromosomes, the first abnormal chromosome found in the leukemias, occurs in over 90 percent of patients" (454). Applying therapy may reduce of Philadelphia in the white blood cells. In the Cancer Book, the author explained that the basic cause of leukemia is still unknown. Factors such as exposure to radiation, chemicals, and certain drugs may cause the disease: "Certain chemicals, such as benzene, have long been known to cause damage to bone marrow calls which form the blood, and it is logical to conclude they can also cause a cancer in those cells" (378).
Also, the genes called oncogenes may be directly involved in the development of many types of cancers, including leukemia: Oncogenes are cancer-causing genes that are part of many people's normal genetic makeup. These genes can apparently be activated under circumstances that has not yet identified..by identifying and understanding specific oncogenes, people who are considered at risk can be identified long before a cancer begins. Although this is a long way in the future.
.the concept of the oncogene has given scientists a new and fundamental approach to the study of cancer that much believe will yield fruitful result. (379) The book further explained the causes of leukemia, and it says the hereditary causes of the disease are still far form being fully understood. There are chances that close relatives of leukemia patients have a risk of getting the disease. The greatest possibility is found in the identical twin of a child who has the acute leukemia before the age of eight: "Approximately 20 percent of these individuals will develop the disease within one year of their twin's diagnosis" (379).
This shows that genetics are playing an important role in the disease. But whether heredity is also involved in all cases is still an unanswered question. According to the Personal Health Report, leukemia may be caused by other types of disease that damage the bone marrow, or anticancer drug used to treat other variety of cancer: "Diseases that cause severe depression of the marrow, such as aplastic anemia, are associated with a high incidence of leukemia." (356) Patients that ...
