Leukemia 1990
Leukemia is an issue of major concern in medicine today, especially given the fact that it affects children. There are different types of the disease; each one is reported to have different occurrence. In the United States alone, there were 2000 cases of acute lymphoblastic leukemia (ALL) diagnosed among children each year back in the 90s. Acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) occurred in 500 and 100 children respectively. Pui’s article “Childhood Leukemias” reviews the disease in detail and covers risk factors, pathological features, cell classification, evolution in clinical management of different types of leukemia, effects of the therapies and future considerations for the management of the disease.
Risk Factors
According to the article, there was still no plausible explanation for 90 percent of childhood leukemia cases (Pui, 1995). However, some types of leukemia are hereditary. ALL and AML are among the types of leukemia that have hereditary influence. Chromosomal rearrangement, especially among twins, is also another risk factor related to the development of the disease. Furthermore, children exposed to carcinogens, chemicals and ionizing radiation at an early age are also at risk of developing the disease (Pui, 1995).
Pathological Features and Cell Classification
First of all, it must be noted that the expansion of clonal immature lymphoid or myeloid cells causes leukemia. The cells’ expansion is blocked during the process of expansion, which causes different genotypes and phenotypes and presents various characteristics of the disease. It becomes evident from the article that the differences in genotypes and phenotypes cause the diverse nature and involve different characteristics of childhood leukemia.
There are various cell classification systems for the disease, such as the French-American-British system, which has helped in distinguishing eight subtypes of myeloid leukemia. The system has also been applied in the classification of ALL, distinguishing among three subtypes of ALL. This classification, therefore, relies on the cytoplasmic antigens in the differentiation of various types of leukemia.
Another classification feature is related to cellular and molecular genetic characteristics of leukemia cells. This method makes it possible to classify the type of leukemia by using the number of chromosomes in every cell affected by leukemia. The classification is important as it allows not only predicting a diagnosis and prognosis, but also identifies the sites involved in leukemic transformation and multiplication (Pui, 1995).
Evolving Areas in Clinical Management
This part of the article looks at the different therapies available in the management of leukemia. Risk-specific therapy is one of the most important management methods that helps to deal with leukemia. This therapy acknowledges the inappropriateness of a uniform approach to the different types of leukemia and their prognosis. For this reason, it suggests specific therapies for ALL, AML and CML. Among the treatment suggested there are glucocorticoid, vincristine and asparaginase for ALL, cytarabine and anthracycline, in addition to chemotherapy for AML, and allogeneic bone marrow transplant for CML.
However, according to the article, there are alternative management methods, which include intrathecal chemotherapy. This method is applicable for patients with more than 100,000 white-cell count. The method is more effective than traditional chemotherapy and, in addition, is less toxic. Another management method is cell growth and drug-sensitivity testing, which helps in testing the response of the leukemia cells to drugs. While the results have been positive for AML drugs, the lack of survival of bone marrow cells has been a challenge for ALL leukemic cells. However, using stomach cells that duplicate bone marrow environment has been especially helpful for culturing cells for ALL.
Late Effects
Despite the management capabilities of therapies prosed, there are risks of adverse effects in later years. The risks include development of central nervous tumors and other types of cancers. Specifically, the therapies have the risk of increasing 7-fold and 22-fold cancers and central nervous tumors (Pui, 1995). Furthermore, cranial irradiation had its risks such as brain tumors, especially for children who underwent the process at the age of five years old or before. Bone marrow transplantation, on the other hand, presented greater risk (sevenfold) for brain tumor, melanoma, and non-Hodgkin’s lymphoma. Other effects include neuropsychological deficits and endocrine dysfunction following cranial irradiation, in addition to cardiomyopathy. Further effects include short stature and obesity, especially among children who underwent cranial irradiation at a young age.
Future Considerations
Developing therapies for patients with poor response to the available treatment remains a major concern for leukemia specialists. Bone marrow transplant from none-related donors has a positive outlook for patients with relapses. With better research and removal of complication, bone marrow transplantation looks to be one of the most important therapies for leukemia. Leucocyte infusion, on the other hand, should be especially feasible and effective for patients with CML, in addition to its use in other types of leukemia. The idea in this case is to use therapies that are successful in the management of one type of leukemia in other related types. Even more important is that research in the treatments should be thorough to avoid any late effects, most of which can be life threatening to the patient. It is for this reason that there is need to develop antileukemic drugs that improve the therapeutic index of the drugs through the reduction of their dispositional variability.
References
Pui, C. (1995). Childhood Leukemias. The New England Journal of Medicine, 332(24), 1618-1630.