Lung Cancer, Leukemia, Obesity and Alzheimer's Disease

Introduction

This paper provides an overview of four major diseases: lung cancer, childhood leukemia, obesity, and Alzheimer's disease. For each disease, a definition, risk factors, treatments, prognosis, and prevention strategies are discussed. The paper also includes brief literature reviews of four relevant scholarly articles.

Lung Cancer

The lungs are the organs that enable human beings to breathe — to inhale and exhale. Their primary function is to supply oxygen to every cell in the body. Cancer cells are abnormal, deformed cells characterized by rapid growth and multiplication compared to healthy cells. Lung cancer begins in the lung tissues when lung cells start to become deformed. It is the deadliest cancer for human beings; more people die from lung cancer each year than from breast, colon, and prostate cancers combined. Older adults are most likely to develop lung cancer, and it rarely affects people under the age of 45 (Roth, Hong & Cox, 2008). In the USA, lung cancer is the leading cause of cancer death in both males and females. It arises after recurring damage to the hereditary material of the cell. Tobacco smoke is, without doubt, the most common cause of such damage and is responsible for approximately 85% of lung cancer deaths in the USA. In contrast, the smoking patterns in other countries determine the prevalence of lung cancer in their societies ("lung cancer," 2012).

There are other carcinogens found in the workplace that also cause lung cancer. Chemical workers are affected by bischloromethyl ether and chloromethyl ether, while those involved in copper smelting are affected by arsenic. Asbestos affects those involved in shipbuilding. Similarly, miners who work in uranium and fluorspar mines are exposed to radon, which can also be hazardous for some private residents. Research has found that European Americans are less likely to develop lung cancer than African Americans ("lung cancer," 2012).

Lung cancer is often referred to as bronchiogenic cancer or bronchiogenic carcinoma (Suliman, Qureshi & Akhter, 2009). Nearly all types of lung cancer begin in the bronchi — specifically in the cell linings. Lung cancer is categorized into two main types based on how the cells appear under a microscope: SCLC (small cell lung cancer) and NSCLC (non-small cell lung cancer). Both types have different patterns of development and growth, and for this reason the treatments used to address them differ as well. Classification of lung cancers is therefore determined by the cell type present in the tumor. The disease typically spreads to the brain, bone, liver, or bone marrow. Cough, shortness of breath, hoarseness, blood in the sputum, and pain are the main symptoms of lung cancer. In some types, cancer cells themselves produce hormones or other substances that result in imbalances and additional symptoms ("lung cancer," 2012).

Physical examination, chest X-rays, bronchoscopy, or percutaneous needle biopsy (insertion of a fine needle through the skin and into the lung to obtain tissue for examination) can be helpful in diagnosing lung cancer. In many cases, a definitive diagnosis is completed after evaluation of surgical specimens. CAT scans or magnetic resonance imaging (MRI) may be used to evaluate suspected sites of metastasis ("lung cancer," 2012). Helical low-dose CAT scanning, a specialized method, is also sometimes used for initial diagnosis because it can detect small tumors before they spread further in the body. Lung cancer is staged according to its location, extent, cell structure, and growth pattern. Together with the patient's overall health, this staging guides treatment decisions ("lung cancer," 2012).

Generally, treatment involves surgical removal of the tumor, either alone or combined with external-beam radiation therapy or chemotherapy using one or more anticancer drugs ("lung cancer," 2012). When the cancer remains localized, photodynamic therapy may also be used. As far as prevention is concerned, the most effective measure is either never starting to smoke or quitting. In ex-smokers, the risk of lung cancer begins to decrease approximately five years after quitting. After fifteen to twenty years without smoking, the chances of developing lung cancer diminish by as much as 80% ("lung cancer," 2012).

Cigarette smoking has been unanimously identified as the major contributor to all lung cancers (Suliman, Qureshi & Akhter, 2009). Therefore, any strategy for combating lung cancer must include smoking avoidance, smoking cessation, and anti-smoking initiatives ("Lung Cancer," 2007). Every patient who smokes must be encouraged to quit, and this effort must be supported by healthcare staff involved in their care. All hospitals should have smoking cessation support groups, and pharmacotherapy and nicotine replacement therapies should be made readily available. It is also necessary to avoid breathing in environments where others smoke and to determine whether one's home or workplace is exposed to cancer-causing chemicals. Indoor radon levels should be monitored, particularly at home, as a further preventive measure. Regardless of smoking status, eating a healthy and balanced diet rich in fruits and vegetables can also reduce the risk of lung cancer ("Lung Cancer," 2007).

Childhood leukemia is the most frequently occurring type of cancer in children. In this cancer, white blood cells become abnormal and begin appearing in the bone marrow. As a result, the rapid expansion of abnormal white blood cells crowds out the healthy cells in the bloodstream, increasing the risk of developing infections ("Childhood Leukemia"). The risk factors for childhood leukemia are mostly unknown. However, the chances of developing the disease are increased if the child has an inborn disorder such as Down syndrome, ataxia telangiectasia (an inherited immune system problem), a sibling — particularly an identical twin — with leukemia, a history of exposure to high levels of radiation, prior chemotherapy or chemical exposure, or a record of immune system suppression ("Childhood Leukemia").

Common symptoms of childhood leukemia include fatigue or pale skin, infections and fever, easy bleeding or bruising, severe tiredness or weakness, shortness of breath, and cough. Additional symptoms can include bone or joint pain, swelling in the abdomen, face, arms, underarms, sides of the neck, or groin, swelling above the collarbone, loss of appetite or weight loss, headaches, seizures, balance problems, abnormal vision, vomiting, rashes, and gum problems ("Childhood Leukemia").

Several tests are used to diagnose childhood leukemia. These include blood tests to measure the number of blood cells and examine their appearance. Sometimes bone marrow is taken from the pelvic bone to confirm the diagnosis. A lumbar puncture is also performed to check for leukemia cells in the cerebrospinal fluid — the fluid in which the brain and spinal cord are immersed ("Childhood Leukemia").

Childhood Leukemia

Treatment for childhood leukemia depends primarily on the type of leukemia and other factors. The primary treatment is chemotherapy, in which the patient receives anticancer drugs orally, intravenously, intramuscularly, or directly into the spinal fluid. To prevent the return of leukemia, cycles of maintenance therapy are administered over a period of two to three years. Doctors also use targeted therapy, which focuses on specific components of cancer cells and works differently from standard chemotherapy. It is often regarded as a preferable treatment because its side effects tend to be less severe ("Childhood Leukemia").

Radiation therapy uses high-energy radiation to kill cancer cells and shrink tumors, and is frequently used to prevent or treat the spread of leukemia to other parts of the body. Surgery is rarely used to treat childhood leukemia. When standard treatment is insufficiently effective, a stem cell transplant may be the best option. This method involves transplanting blood-forming stem cells after whole-body radiation combined with high-dose chemotherapy to first destroy the child's bone marrow ("Childhood Leukemia").

The condition of obesity results from excessive fat accumulation in the body. It can be defined as a weight more than 20% above what is considered normal according to standard age, height, and weight tables, or by a complex formula known as the body mass index (BMI) ("obesity," 2012). According to estimates, 30–35% of Americans are overweight or obese ("obesity," 2012). The main cause of obesity is the consumption of more calories than the body requires for energy, as the surplus calories are stored as fat. Other contributing factors include physical inactivity and insufficient exercise. Overeating may result from unhealthy eating patterns established by family and cultural environment. Obesity can also be worsened by psychological distress, an emotional reliance on food, or easy access to high-calorie foods ("obesity," 2012).

Major treatments for weight loss include wiring the jaw shut, reducing stomach size through surgery, and intestinal bypass operations in which a large portion of the small intestine is bypassed to restrict the area where food is absorbed. However, diet and exercise remain the primary treatments for obesity, complemented by emotional and behavioral support ("obesity," 2012). An overweight or obese person can be treated through a two-step process of assessment and management. Assessment involves evaluating the degree of obesity and overall health status, while management includes weight loss, maintenance of a healthy body weight, and measures to control other risk factors. Because obesity is a chronic disease, both the patient and the practitioner must understand that lifelong effort is essential for successful treatment. There is strong evidence demonstrating that weight loss reduces blood pressure, lowers blood glucose, and improves dyslipidemias.

As the population ages, Alzheimer's disease is becoming an increasing health, social, and public well-being concern. It is a form of dementia characterized by the progressive deterioration of thinking abilities severe enough to interfere with social, occupational, and intellectual functions, causing severe and permanent loss of intellectual capacity. Patients with Alzheimer's begin by becoming forgetful and progressively lose memories — including those of family events — as well as skills acquired earlier in life (Nowotny, Kwon & Goate, 2001). After several years with the disease, patients may become completely incapable of even the most basic self-care. Alzheimer's disease therefore affects not only the patient but also imposes a heavy burden on family members and communities. It is recognized as the primary cause of late-life dementia, and the population most commonly affected is aged over 65 (Nowotny, Kwon & Goate, 2001).

Alzheimer's disease is a degenerative disease of the nerve cells present in the cerebral cortex. It may lead to deterioration of the brain and senile dementia. The disease causes problems with memory, thinking processes, and behavior, and therefore cannot be regarded as a normal part of aging. The disease worsens over time. It is distinguished by the irregular accumulation of plaques and by abnormal nerve cells. Alois Alzheimer was the first to describe these changes in nerve cells in 1906. Plaques form as excessive amounts of amyloid-beta protein are released and accumulate. These are normal proteins, though their precise function in the body is not fully understood. Neurofibrillary tangles — deformed nerve cells — prevent manufactured products within the cell from being transported to organelles and target sites ("Alzheimer's disease," 2012).