BIOLOGY 20 General Biology : Acute Lymphocytic Leukemia

Introduction

Cancer can occur in any part of the body and results in cells growing at an abnormal rate, outnumbering the normal cells of the body. The abnormal growth of the cells can give rise to solid tumors.

Cancer is one of the most prominent causes of death. Tobacco is responsible for the majority of lung cancer deaths worldwide (Warren & Cummings, 2013). Cancer may be caused by genetic factors or external mutagenic agents.

This purpose of the report is to describe the causes, symptoms, diagnosis, treatment and prevention strategies for a type of cancer called Acute Lymphocytic Leukemia (ALL).

Acute Lymphocytic Leukemia

Acute Lymphocytic Leukemia (ALL) is also called Acute Lymphoblastic Leukemia. Acute means that the cancer spreads very quickly and is fatal. It is called lymphocytic meaning that it develops from immature forms of white blood cells called lymphocytes. This cancer occurs as a result of excessive production of immature cancerous white blood cells. It inhibits the formation of normal cells in the bone marrow thereby causing death (Harrison & Johansson, 2015). The leukemia cells invade the bloodstream and spread to other body parts like the lymph nodes, central nervous system, spleen, liver and testicles.

Symptoms, diagnosis, staging, and prognosis

Symptoms

The symptoms associated with ALL, include fatigue, fever, shortness of breath, persistent infections, nose and gum bleeding, weight loss, loss of appetite, night sweats, bone and joint pain. Enlargement of liver and spleen and enlargement of lymph nodes present in the underarms, neck and groin can result in the formation of lumps or swelling (Www.cancer.org, 2017).

Diagnosis

Determination of the morphologies of the lymphoblasts by microscopy and immunophenotypic determination by flow cytometry are some of the essentials required for correctly diagnosing ALL. Chromosomal analysis is an important tool for diagnosis. Moreover, RT-PCR, multiplex ligation dependent amplification of probes, FISH and flow cytometry helps to identify translocations, cellular DNA content and chromosomal abnormalities, respectively (Inaba, Greaves & Mullighan, 2013).

Staging

The leukemia staging involves accumulation of leukemia cells in the spleen or liver and by counting blood cells. The stages of ALL include: B cell and T cell staging. The B cell ALL stages include Early pre-B ALL, common ALL, Pre-B ALL and Mature B cell ALL or Burkitt leukemia. The T cell ALL stages include Pre-T ALL and mature T-cell ALL (Www.cancercenter.com, 2017).

Prognosis

Certain factors help in the prognosis of ALL. These include: age (younger patients show better prognosis), initial count of white blood cells, ALL subtypes (patients with T cell ALL have better chances of prognosis than individuals with Burkitt leukemia or B cell ALL), chromosome translocations (individuals with Philadelphia chromosome specific ALL suffer from poor prognosis), good response to chemotherapy, among others (Schultz et al., 2014). The IKZF1 gene that encodes transcription factors are altered in 15% of B ALL cases (Inaba, Greaves & Mullighan, 2013).  

Treatments

Treatment is carried out in 3 phases. These are induction, consolidation and maintenance. Induction helps in remission. Different chemo drug combinations are used like Vincristine, Prednisone or Dexamethasone and Doxorubicin. Other drugs include Cyclophosphamide, L-asparaginase, methotrexate, among others. Patients with Philadelphia chromosomes are given Imatinib. After remission, the next phase called consolidation involves a short chemotherapy course with the same drugs but in high doses. Following consolidation, patients are subjected to maintenance chemotherapy, which includes the use of drugs like 6-mercaptopurine or methotrexate. In some cases, other drugs like prednisone or vincristine are used in combinations (Pui et al., 2015). Other alternative treatments include stem cell transplantation, radiation therapy, T cell therapy, acupuncture, insulin potentiation therapy, infusion with high vitamin C and B17 doses, among others (Davila et al., 2014).

Causes or risk factors

The risk factors or causes of ALL include radiation exposure, chemical exposures to chemotherapy drugs and benzene, infection caused by human T cell lymphoma virus can give rise to T-cell ALL (Zhou et al., 2014). The Epstein Barr virus can cause Burkitt lymphoma (Rowe, Fitzsimmons & Bell, 2014). Certain inherited syndromes like Down, Klinefelter syndromes, Ataxia-telangiectasia, can cause ALL (Narayanan, & Shami, 2012). Studies revealed the role of the cell cycle genes CDK2, CCND1 and CMYC in the development of ALL (Jayaraman & Jamil, 2012). Individuals with polymorphisms in the thymidylate synthase gene are more prone to develop ALL (Akin et al., 2017).

Incidence rates

Estimates for ALL in the United States of America for 2017 were found to be 5970 cases of ALL and about 1440 deaths. From 2010-2014, the number of ALL and death cases were 1.7 and 0.4, respectively per 100,000 men and women per year. About 0.1% of individuals are diagnosed with ALL during some point in their lifetime. In 2014, approximately 81,837 individuals were living with ALL in USA (Www.cancer.org, 2017).

Resources

Resources that a patient can use include diagnostic tests like complete bone marrow count, bone marrow aspiration or biopsy, genetic tests, among others. Other resources include cord blood or bone marrow transplant, immunotherapy, Cellie cancer coping kits, support groups who provide safe environments dedicated to give support, hope and education to the affected individuals (Www.chop.edu, 2017).

Prevention

ALL can be prevented by decreasing exposures to radiation, avoiding alcohol, tobacco consumption, use of drugs like marijuana. Cancer in general can be prevented by eating a healthy diet and healthy weight and exercising (Www.who.int, 2017).

Conclusion

ALL affects the white blood cells of bone marrow and can give rise to severe consequences that can eventually result in death. Proper prevention strategies and medications are needed for early detection and treatment of patients.

References

Akin, D. F., Oner, D. A., Sipahi, K., Mumcuoglu, M., Kurekci, E., Ezer, U., & Akar, N. (2017). Screening of polymorphisms in the folate pathway in Turkish pediatric Acute Lymphoblastic Leukemia patients. Egyptian Journal of Medical Human Genetics, 18(4), p349-353. 5p.

Davila, M. L., Riviere, I., Wang, X., Bartido, S., Park, J., Curran, K., ... & Qu, J. (2014). Efficacy and toxicity management of 19-28z CAR T cell therapy in B cell acute lymphoblastic leukemia. Science translational medicine, 6(224), 224ra25-224ra25.

Harrison, C. J., & Johansson, B. (2015). Acute lymphoblastic leukemia. Cancer Cytogenetics: Chromosomal and Molecular Genetic Aberrations of Tumor Cells, 198.

Inaba, H., Greaves, M., & Mullighan, C. G. (2013). Acute lymphoblastic leukaemia. The Lancet, 381(9881), 1943-1955.

Jayaraman, A., & Jamil, K. (2012). Clusters of CDK2, CCND1, and CMYC genes involved in cancers: Acute Lymphocytic Leukemia (ALL) as a model. Biology and Medicine, 4(1), 37.

Narayanan, S., & Shami, P. J. (2012). Treatment of acute lymphoblastic leukemia in adults. Critical reviews in oncology/hematology, 81(1), 94-102.

Pui, C. H., Yang, J. J., Hunger, S. P., Pieters, R., Schrappe, M., Biondi, A., ... & Escherich, G. (2015). Childhood acute lymphoblastic leukemia: progress through collaboration. Journal of Clinical Oncology, 33(27), 2938-2948.

Rowe, M., Fitzsimmons, L., & Bell, A. I. (2014). Epstein-Barr virus and Burkitt lymphoma. Chinese journal of cancer, 33(12), 609.

Schultz, K. R., Carroll, A., Heerema, N. A., Bowman, W. P., Aledo, A., Slayton, W. B., ... & Gaynon, P. S. (2014). Long-term follow-up of imatinib in pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia: Children's Oncology Group study AALL0031. Leukemia, 28(7), 1467-1471.

Warren, G. W., & Cummings, K. M. (2013). Tobacco and lung cancer: risks, trends, and outcomes in patients with cancer. In American Society of Clinical Oncology educational book. American Society of Clinical Oncology. Meeting (pp. 359-364).

Www.cancer.org. (2017). Signs and Symptoms of Acute Lymphocytic Leukemia. Cancer.org. Retrieved 12 November 2017, from https://www.cancer.org/cancer/acute-lymphocytic-leukemia/detection-diagnosis-staging/signs-symptoms.html

Www.cancer.org. (2017). What Are the Key Statistics About Acute Lymphocytic Leukemia?. Cancer.org. Retrieved 12 November 2017, from https://www.cancer.org/cancer/acute-lymphocytic-leukemia/about/key-statistics.html

Www.cancercenter.com. (2017). Stages of Acute Lymphocytic Leukemia | CTCA. CancerCenter.com. Retrieved 12 November 2017, from https://www.cancercenter.com/leukemia/stages/tab/acute-lymphocytic-leukemia/

Www.chop.edu. (2017). Acute Lymphoblastic Leukemia and the Cellie Cancer Coping Kit: Justin's Story | Children's Hospital of Philadelphia. Chop.edu. Retrieved 12 November 2017, from https://www.chop.edu/stories/acute-lymphoblastic-leukemia-and-cellie-cancer-coping-kit-justins-story

Www.who.int. (2017). Cancer prevention. World Health Organization. Retrieved 12 November 2017, from https://www.who.int/cancer/prevention/en/

Zhou, Y., Zhang, S., Li, Z., Zhu, J., Bi, Y., Bai, Y., & Wang, H. (2014). Maternal benzene exposure during pregnancy and risk of childhood acute lymphoblastic leukemia: a meta-analysis of epidemiologic studies. PloS one, 9(10), e110466.