Risk Factors and Occurrence of Leukemia - Research Paper Example

LEUKEMIA Institute Leukemia is a neoplasm of the white blood cells of the human body. It is divided into different types which include acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), adult T-Cell leukemia and hairy cell leukemia. There are many underlying factors that have been identified in the causation of leukemia. These include radiations, chemotherapy, certain genetic disorders as well as the human T-cell leukemia virus-1. The pathological condition affects the males more commonly and is seen mainly amongst the whites. The different types of leukemia present with different clinical features and there are differing signs and symptoms. The condition affects the bone marrow as well as the blood with the presence of altered cells in the bloodstream. Different diagnostic procedures are utilized to diagnose this condition. These include the full blood count as well as blood smears. Biopsy of the bone marrow is also performed for a definitive conclusion. Each form of leukemia has its own pharmacological treatment directed towards treating the condition. Bone marrow transplant is the last treatment resort for all types of leukemia. Leukemia Introduction: Neoplasms within the blood arise when there is disruption in the normal pattern of differentiation of blood cells. Leukemia falls within the classification of the cancerous pathological conditions of the blood which results in a rise in the white blood cells at their site of production that is the bone marrow as well in the blood which is present in the circulation. There is no specific definitive cause that has been identified for this condition but there are many risk factors and proposed causes which are considered to increase the susceptibility of the development of leukemia. Leukemia is a malignancy which is further categorized into many subtypes. These include the acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), adult T-Cell leukemia and hairy cell leukemia (Davidson et al 2009; Kumar et al 2005). Risk Factors and Occurrence: The occurrence of leukemia has been associated with different causes. It has been analyzed that alterations in the normal chromosomal development which may be due translocations as well as rearrangements in the chromosomal structure may lead to leukemia. An interesting aspect of leukemia is that it is seen to be present at a higher rate in the people who suffer from other genetic pathological conditions. A higher incidence of acute leukemia is seen in people who suffer from Bloom Syndrome, Fanconi anemia and ataxia telangiectasia. In a similar manner, increased susceptibility of childhood leukemia is seen in children suffering from Down’s syndrome and neurofibromatosis type I. A virus which is referred to as human T-cell leukemia virus-1 (HLTV-1) has been considered to be a pathological agent that leads to the condition of leukemia. It has also been seen that some forms of therapeutic procedures also serve as factors for the formation of leukemias. These include ionizing radiations as well as a few agents of chemotherapy. Radiations due to wars are also associated with the same effects as the ionizing radiations associated with therapeutic procedures. Alkylating drugs and contact with benzene for a long time is also linked to leukemia. It has also been proved that there is a greater predisposition for the condition to develop in men than in women. Furthermore, there is an increased chance of the development of this condition in people who have inefficient immune systems. Hypogammaglobulinemia is an example of one such condition which reduces the efficiency of the immune system and hence raises the risk for the development of leukemia (Davidson et al 2009; Kumar et al 2005). The National Cancer Institute in the United States has presented with interesting findings with regard to the occurrence of leukemia in the country with regard to age, sex and racial characteristics. Between the years of 2004 and 2008, it was analyzed that the highest percentage of people who were diagnosed with the condition lied in the age group of 75 to 84 years. The susceptibility for the diagnosis of leukemia increases with advancing age. The only exception is for people below the age of 20 years who also have a raised chance of being diagnosed with the condition. Amongst the races, the whites have the highest risk for the development of leukemia in the United States. The Asians and the Pacific Islanders have the lowest risk for being diagnosed with leukemia in comparison to the other races. According to statistics, on the first day of the year 2008, there were 142,702 males and 110648 females who had a history of being diagnosed with leukemia and had survived the disease. These statistics clearly highlight the fact that the males have a greater chance of developing the disease. It is indicated that in the year 2010, there will be approximately 43,050 people who will develop this condition and the disease will result in the death of approximately 21,840 people in the same year (National Cancer Institute 2011). Types and Clinical Features of Leukemia: There are different types of leukemia and they have their own clinical presentations and features. Acute leukemias are mainly categorized into acute lymphoblastic leukemia and acute myeloid leukemia. These leukemias result in an increase in the primal bone marrow cells within the bone marrow which tend to replace the normal cells within the bone marrow. These alternate cells tend to produce abnormal cells which are different from the normal bone marrow cells. Acute lymphoblastic leukemia is mainly seen in children below the age of 15 years. The lymphoblasts that are formed in this leukemia do not mature and precursor B and precursor T cells are seen in this condition. Acute myeloid leukemia is a condition in which the myeloblasts replace the normal bone marrow cells. This condition is mainly seen in people above the age of 15 years and below the age of 40 years. These acute leukemias present with similar signs and symptoms owing to the fact that primordial cells tend to replace the marrow in both the conditions. The patient may present with anemia, reduced number of neutrophils as well as thrombocytopenia. The enlargement of the lymph nodes, spleen as well as the liver is also seen but it is more marked in acute lymphoblastic leukemia. The increase in the substance of the bone marrow leads to the presentation of pain in the bones. The patient may be lethargic due to anemia. Fever may also be a presentation owing to the fact that the patient has an increased susceptibility to develop infections. This is owing to the fact that the number of normal white blood cells is reduced. Bleeding symptoms are also common presentations owing to the thrombocytopenia. These include bleeding from the nose, gums as well as bleeding into the organs. Other bleeding symptoms include ecchymoses and petechiae. The bleeding signs are more common amongst patients of acute myeloid leukemia. The central nervous system may also get affected and the patient may present with headaches as well as vomiting. The cranial nerves might also lose their normal functioning (Davidson et al 2009; Kumar et al 2005). Chronic lymphocytic leukemia is another type of leukemia and it is considered to be the most widespread type. It is seen between the years of 65 to 70. In this condition there is increased differentiation of B lymphocytes which are not capable of generating the normal immune responses. This results in reducing the efficiency of the immune system of the patients. The condition has a greater predisposition towards males. The patients may be lethargic and they may complain of reduction in their weight. This may also be accompanied with enlargement of the lymph nodes, liver and the spleen (Davidson et al 2009; Kumar et al 2005). Chronic myeloid leukemia is a form of leukemia which involves all the types of white blood cells in the bone marrow but mainly encompasses upon the granulocytes. This form of leukemia is seen mainly in people who are above the age of fifty years. This condition has two phases which includes the chronic variant that is less severe and treatment modalities prove to be effective for this phase. There is an accelerated phase that tends to be a period of greater differentiation and is more severe than the chronic phase. The last phase is the blast crisis where the severity of the disease is increased and it may develop into an acute leukemia. The patients of chronic myeloid leukemia present with reduction in weight along with shortness of breath and lethargy. They may also have pain in the abdomen. Enlargement of the spleen and liver are also common presentations (Davidson et al 2009). Adult T- Cell Leukemia is another type of leukemia that results due to the virus human T-cell leukemia virus type 1. This condition is seen mainly in Japan and Africa. The condition results in enlargement of spleen, liver and lymph nodes accompanied with abnormal lymphocytes in blood as well as raised calcium levels. For a large number of infected cases, the disease may result in death. Hairy cell leukemia is also an uncommon form of leukemia and it tends to affect mainly the men from the Caucasian races. It is a cancer of the B cells and it is known as hairy cell leukemia as the cancerous cells look like hair. The most marked finding is the enlargement of the spleen and these patients have a susceptibility of being infected with bacterial infective agents (Kumar et al 2005). Diagnosis and Treatment: The diagnosis is principally based on clinical examination in association with other investigations. These include the full blood count and the blood smears to assess the number of blood cells as well as to check the appearance of the cells. The aspiration of the bone marrow can also be taken and subjected to tests to check for the type of leukemia present (Davidson et al 2009). Different forms of treatment are available for the leukemia patients. The different pharmacological treatments for acute lymphoblastic leukemia include corticosteroids, mercaptopurine, cyclophosphamide, vincristine, daunorubicin as well as asparginase. The best form of treatment which is widely used is the combined therapy of vincristine and prednisone. The cancer cells have shown a tendency to move towards the brain and the testes. Therefore, to make the therapy more effective methotrexate is administered intrathecally. The treatment of acute myeloid leukemia comprises of administration of cytarabine and idarubicin. It is advisable to provide transfusions of platelets along with antibiotic therapy to these patients for the relied of the signs and symptoms. In chronic myeloid leukemia, the aim of the treatment is to increase the level of hemoglobin and to lower the level of the granulocytes. Imatinib is considered to be the most effective form of treatment measure employed for these patients. In the case of chronic lymphocytic leukemia, there are different treatment regimens available. Fludarabine is used along with cyclophosphamide and mitoxantrone. Cloramburacil is also a pharmacological agent which is administered alone and leads to the treatment of the condition. Alemtuzumab is a form of treatment which is used in patients who develop the disease again after the initial treatment is ended. In all types of leukemia, if all treatments fail, bone marrow transplant is the only option to treat the condition. This option is not used for the elderly patients (Davidson et al 2009; Katzung 2004). Conclusion: Leukemia is a cancerous condition of the white blood cells in the human body. It is classified into many different types which include acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphoblastic leukemia and chronic myeloid leukemia. These leukemias have differing features and present in different age groups. The main signs and symptoms seen in leukemia include abnormal blood cells in the blood associated with reduced efficiency of the immune system and the enlargement of the liver, spleen and lymph nodes in most of the cases. The diagnosis is based upon blood count, blood smear and the analysis of the bone marrow. Different pharmacological treatments are available for the different forms of leukemia. The final treatment for unresponsive leukemia is the transplantation of bone marrow. References Top of Form Davidson, S., & Innes, J. A. (2009). Davidsons essentials of medicine. Edinburgh: Elsevier/Churchill Livingstone. Katzung, B. G. (2004) Basic and Clinical Pharmacology. New York: McGraw Hill Medical. Print. Bottom of Form Top of Form Kumar, V., Abbas, A. K., Fausto, N., Robbins, S. L., & Cotran, R. S. (2005). Robbins and Cotran pathologic basis of disease. Philadelphia: Elsevier Saunders. National Cancer Institute. (2011). Cancer Statistics: SEER Stat Fact Sheets: Leukemia. U.S. National Institutes of Health. Retrieved from: http://seer.cancer.gov/statfacts/html/leuks.html Bottom of Form Read More