Leukemia is a type of cancer that starts in the blood forming tissues, such as the bone marrow, and then spreads in the body. The bone marrow is a name given to the soft material which is found in the middle of most bones. Bone marrow contains cells which are responsible for forming blood. The name given to these specialized cells is stem cells. All stem cells undergo their maturation phase within the bone marrow and then travel to different parts of the body through the blood vessels once they have been matured.
Each cell that a stem cell matures into has a separate function. For instance red blood cells are responsible for transporting oxygen and carbon dioxide away from all the cells of the body. Platelets are responsible for helping in the formation of blood clots in order to prevent excessive bleeding and loss of blood from wounds and injuries. White blood cells are responsible for combating different infections.
White blood cells are of two main types namely monocytes and granulocytes. The main cells of the lymphoid tissues of the body are known as the lymphocytes and constitute a major portion of the immune system of every individual. Lymphocytes, similar to the blood cells originate from marrow of bones.
What is Leukemia?
Leukemia is the name given to a group of specific cancers of the blood which are diagnosed in nearly 44,000 children and adults every single year. Almost 11% of all new cases of leukemia that are diagnosed, are those diagnosed in children. This percentage is equal to 3,800 childhood leukemia cases each year. It is important to understand that the mechanism of childhood leukemia is different from the leukemia that affects adults. Children also have a different survival rate as compared to adults.
Types of Leukemia
Leukemia is broadly divided into two main subgroups in case of adults. These are acute leukemia and chronic leukemia. Acute leukemia is the name given to a group of cancers whose progress is highly rapid and is characterized by the production of a large number of abnormal cells in the blood which hinder the normal functionality of the bone marrow as well as the blood.
In case this type of cancer is left untreated, it can progress rapidly to manifest a number of symptoms in the body. The reason why prominent symptoms are not seen in many cases when the cancer is diagnosed is the fact that many normal cells of the body are still capable of functioning normally despite the production of and destruction caused by the abnormal cells.
Chronic leukemia is the name given to the form of leukemia which progresses over a long period of time, but has the potential to become acute during some phase of the cancer. The process of the development of chronic leukemia can take several years. It has been observed that nearly 55% of all leukemia cases are acute where as 45% of them are chronic. The 5 year survival rate for all leukemia cancers is about 48%. The survival rate of the patients is entirely dependent upon the age, gender, form of leukemia and race.
Risk factors for Leukemia
Some of the most prominent risk factors in case of adult leukemia include exposure to certain chemicals including benzene and various drugs used in chemotherapy. Exposure to radiation is also a major risk factor. All the different types of leukemia that affect adults or children initiate from different types of blood cells.
ALL, or the acute lymphocytic leukemia and the CLL or chronic lymphocytic leukemia are the two types of this cancer which originate from lymphocytes. AML, or acute myelogenous leukemia initiates from the granulocytes whereas the chronic myelogenous leukemia originates from the cells which help in the formation of blood, found in the bone marrow.
A rare form of leukemia known as the hairy cell leukemia, or HCL, is characterized by the formation of abnormal lymphocytes which are covered with small projections resembling hair. The most common type of acute leukemia found in the majority of adults is the AML and is responsible for 83% of all leukemia cases. On the other hand, CLL is responsible for 63% of all the chronic leukemia cases that are diagnosed in adults.
There is an immediate need for treatment and medication in all cases of acute leukemia the moment that it is diagnosed in a patient. The first treatment that is given in this case is an aggressive dose of chemotherapy.
Induction is the first phase of the treatment given to patients and is responsible for bringing about a remission. Once the symptoms have successfully disappeared, a second dose of chemotherapy is given to ensure the prevention of a relapse. This phase of leukemia treatment is known as the maintenance therapy.
Cases of chronic leukemia need not be treated with aggressive chemotherapy immediately. In case the symptoms grow worse, the treatment can be initiated in order to gain control of the disease and all of its symptoms. In some cases, chronic leukemia can be cured, but the treatment can keep the leukemia in the phase of remission for a considerable time.
The Leukemia & Lymphoma Society. Access at: www.lls.org/waystohelp/advocate/ The site of the world’s largest organization dedicated to blood cancers includes many sections and features for people with all types of leukemia. Live and archival versions of educational teleconferences and Webcasts enable users to study complicated topics explained by top experts. The site also includes medical news about leukemia, short and longer overviews of the diseases, and information about the organization’s support services for patients.
Leukemia Research. Access at: leukaemialymphomaresearch.org.uk/ Leukemia Research is a British research charity focusing on blood cancers and disorders. The “Information and Education” section offers printable booklets on adult and childhood blood cancers, including some on rare subtypes and conditions. The “News” section includes stories about research developments and other related articles.
Access at: www.cancer.org and select from the menu under “Choose a Cancer Topic.” Detailed guides about specific types of leukemia can be printed by section or as Adobe Acrobat (.pdf) files.
Healthology. Leukemia. Access at: www.healthology.com/content/consumerhealthlibrary/ and click on “Consumer Health Library.” This site offers detailed articles, Webcasts, and transcripts featuring cancer rofessionals.
National Cancer Institute. Leukemia. Access at: www.cancer.gov and click on “Types of Cancer.” The top page of the section links to patient versions of PDQ@ statements on specific leukemia types, clinical trial information, and other NCI publications on this topic.
This article was originally published on 7/12/2014 and last revision and update of it was 9/14/2015.