Lung Cancer - Research Paper Example

Lung Cancer Lung cancer involves the proliferation of abnormal cells of the tissues of the lungs. It could be in the form of adenocarcinoma, squamous carcinoma and large cell carcinomas. Every day we hear saddening news of illnesses and deaths from it. The disease continues to be among the top diseases causing mortality not only among men but also to women around the globe. Despite the advances in technology and medicine, thousands of individuals are diagnosed with the disease having little chance of survival. In the United States, about 203,536 people are found to suffer from the disease regardless of sex with death of over 157, 000 victims in 2010 (www.cdc.gov/cancer/lung). Other countries have showed the same trend. In Europe, many countries showed high rate of deaths with Hungary in the top list having deaths that reached over a hundred victims a day. In Canada, lung cancer accounts for 30% death with cases of women on the rise. Far East Asia is not spared from the disease. Philippines alone have 43 daily cases of deaths. Taiwan and Japan share the same sentiment regarding the disease. China also has continual increase in numbers who die from the disease (Pastorino, 102). This scenario provides a picture that lung cancer is prevalent worldwide regardless of sex. Limiting the incidences of the lung cancer involves understanding the pathophysiology, causes, signs and symptoms, and diagnosis to be able to treat the disease at an earlier stage and to prevent high prevalence of its occurrences. Pathophysiology The normal lung cell consist of two layers namely the columnar cells and basal cells. The columnar that contains mucus and covered with cilia makes up the surface layer. Basal cell which is the second layer contains the nuclei and basement membrane which in turn composes the glands, blood, blood vessels and lymphatic vessels. The initial response to a carcinogenic agent occurs in the tracheobronchial epithelium within the basal cells. Number of cells increase as it is triggered with the inhalation of any carcinogenic agents and referred to as carcinomas. This happens because oncogenes which make the body susceptible to cancer are activated. When a carcinogen enters the body, it binds with the DNA of the lung cells causing changes and differentiation of the cell. The structures of the cells are damaged which may cause abnormal growth. As the cell division continues to occur, the damaged DNA is also passed to the daughter cells and undergoes further mutations. Cell growth becomes unstable and genetic changes accumulate. The pulmoepithelium in turn undergoes malignant transformation from normal epithelium to invasive carcinoma (Day, et al, p 558). Among the lung cancer type, adenocarcinoma is the most prevalent. However, when cancer cells metastasize, the tracheal and broncheal lymph nodes are the earliest to show signs of the spread to distant lymph nodes, organs, kidneys and brain. On the other hand, broncheoalveolar type is usually slow in nature than other types. Pleural effusion results as an effect of direct involvement of the pleura, obstruction of mediastinal lymphatics, throracic duct, pulmonary lymphatics, and atelectasis with pneumonitis and pulmonary embolus. Causes Lung cancer is believed to have many causes. It could be provoked with many carcinogens like tobacco smoke, radiations and viral infections. Although the disease is known to be a familial tendency, the risk depends with the exposure to carcinogenic risk factors. Almost all types of lung cancer are caused by tobacco smoke. About 90% of patients seeking medical help are found to be directly exposed to it. The most affected cells are the small squamous types. Tobacco contains multiple components however, not all of these may cause lung cancer. It is known that there are only a few that may really trigger the cells to undergo changes. Mazzone (p1) in his study identified N-nitrosamines and polycyclic aromatic hydrocarbons to be the two most carcinogens that are related to lung cancer. Many studies had supported this research of Mazzone revealing the presence of high dosage of such components of tobacco in the lungs of most cancer patients. Unfortunately, not only active smokers themselves are found to suffer from lung cancer from tobacco smoke but also extend to affect passive smokers as well. Dockery &Trichopoulos (p 333) in their study revealed that components of tobacco by products inhaled by non smokers who participated in their study had shown the same components that affected active smokers increasing the incidences of lung cancer. The authors further explained that tobacco smoke is among the environmental carcinogens exposing non smokers to show elevated levels of tobacco smoke. However, age of exposure to N- nitrosamines and polycyclic aromatic hydrocarbons, the number of cigarette sticks per day and the duration of smoking play a role in influencing the development of the disease. This is to include other risks factors such as depth of inhalation and the intensity of smoking. Radiation is another carcinogenic agent affecting non smokers. It is the next leading cause of lung cancer. It could come from exposure to x-rays, ultraviolet rays, nuclear reactions, and many other sources that may emit radiation. Cells are damaged by the high radiation frequency that could ionize the DNA of the cells and damage it. Low frequency radiation from cell phones, microwaves, television also is a contributory factor. However, the amount of radiation is not the same that is taken from high frequency sources. Radon could also affect non smokers. Exposure to contaminated air, water from radon and building materials made of asbestos could post as a potential hazard in the development of lung cancer. Radon gas can accumulate in buildings and often times in confined areas such as basement and attics. This is the reason why underground miners are vulnerable to develop lung cancer. A study had shown that miners who were exposed to the same components are found to show evidences that could identify symptoms of lung cancer (Samet, 745). Human papilloma virus (HPV) is yet another culprit of lung cancer. The virus is found to alter how the normal cells function by causing apoptosis which in turn results to cell death and uncontrolled growth of squamous cells. Klein, Amin, and Petersen (p 13) supported this claim where they found out that the virus does not only affect the cervix in women but also is the cause of most squamous cell carcinomas. Other viruses likewise play an important role in the causation of the disease. However, it is through an indirect manner. Signs and Symptoms Although lung cancer is asymptomatic in its early stage, signs and symptoms of it depend on the growth and spread of cancer cells. Coughing and shortness of breath which are always mistaken to be associated with ordinary colds are symptoms of localized growth. Since most individuals consider such coughing as ordinary, lung cancer is diagnosed when it has involved other body parts. As the disease progresses, the cough may interfere with eating and sleeping. The patient can experience continuous episode of coughing during the day and at night time. Chest discomfort and pain are also common. Impingement of tumor on the nerves may cause pain. In other cases, pain may be a sign that the tumor had invaded the chest wall, ribs and muscles. Other symptoms may occur related to the extension of the disease involving other parts. Fever and purulent sputum as a sign of infection is experienced. Dysphagia is a result of compression which may also interfere with the swallowing. As a result, the patient may have difficulty eating that may lead to weight lose, weakness and other health problems like anemia and other conditions. Dyspnea, wheezing, and cyanosis are all related to obstruction of the growing tumor. There is also hoarseness as a result of invasion of the left laryngeal nerve by the tumor. The presence of ulceration may cause hemoptysis that may urge the patient to consult medical help. When the airway is obstructed, collapse of the lungs occurs referred to as atelectasis. Metastasis of the disease may cause several discomforts like headache, hepatomegaly, seizures, syncope, papilledema, weakness, and changes in mental status. All of which if experienced for a duration of time may cause impending doom to the patient. Because signs and symptoms are most often illusive in lung cancer until it metastasizes, individuals should seek consultation when he/ she experiences chronic cough which is persistent, bronchitis with the same characteristics, blood in the sputum or hemoptysis, chest pain, fatigue, unexplained weight loss, and breathing difficulties. These all serve as a warning to the person not to postpone consultation. Diagnosis Since lung cancer could not be reliably diagnosed with history taking alone, diagnostic procedures has to be carried out with the goal to establish diagnosis and determine the stage of the disease. It could be done employing several radiological studies. Initial evaluation to screen the condition or abnormalities of the lungs includes the performance of chest x-ray. However, this procedure is found not effective to most patients. Thus, computed tomography (CT) scan is advised. Positive result may reveal a coin lesion. However, the patient still has to undergo further diagnostic examinations for staging purposes and to determine the proper treatments needed. Radiographic result suggesting nodule with lobulated border, growing nodule or mass, calcification in the detected lesion, and a thick cavitary lesion may also entail further evaluation to include some non surgical but invasive procedures such as angiography, bronchoscopy and cytotoxic examination since the above changes are features of malignancy. Bronchoscopy which is the obtaining of body tissue for study specimen is preferred by most physicians as it has a high diagnostic yield. CT scan is used when liver and adrenals are included for evaluation and confirmation. It is found to be sensitive and reliable in revealing detecting small pulmonary lesions in just a few seconds. Although there is no significant reduction of mortality rate from lung cancer, patients who had undergone screening test show better prognosis compared to those who did not. Reports have it that almost 80% of patients who are screened had a better chance to live even if it is not for a long time. This might be attributed to the early detection of asymptomatic cases who are good candidates for effective treatment. The study of the National Lung Screening Trial Research Team (abstract) reveals that screening test could possibly detect the disease in its preclinical stage in which it may respond effectively to treatments. Treatments Treatment depends on the category and staging of the lung cancer. Small cell carcinomas that are associated with extrathoracic metastasis, aggressive and with extensive involvement of mediastinal region may respond to chemotherapy however small cell carcinomas are advance by the time the patient is diagnosed making their prognosis poor. Chemotherapy is the use of strong drugs purposely to kill cancer cells however it is also known to include destroying healthy cells. Side effects of the therapy comprise of nausea, vomiting, and hair loss. Unfortunately, such side effects are sometimes caused not by the drugs alone but also by the inappropriate dosage of the medication, age, presence of deficiency and the reaction of combined drugs. All of these contribute more insult to the injury. Since among the goal of therapy is to remove cancerous part, surgery is another option in the treatment of lung cancer. However, the procedure is successful only in localized carcinoma and that there are no other body parts affected with cancer cells. Surgery could be lobectomy, the removal of involved lobe and pneumonectomy, the removal of involved lungs. Surgery is also found effective in large cell carcinoma. Ma and company (p 342) exposed that lobectomy is the best solution for primary tumors that did not involved the pleura. They further pointed out that lobectomay is better than other forms of surgery because it has a lesser rate of complications and deaths. It is also revealed that survival rate of operated patients can reach up to three years survival. Similar study of Kocaturk and others (abstract) reported the same success in surgery. The group explained that there is a satisfactory survival rate of patients who undergone complete resection surgery. Radiation which is a form of x-ray that delivers high energy is yet another treatment of lung cancer. It could be in combination with surgery or chemotherapy. Patients can be subjected to radio therapy after operation if deemed necessary. This is when the physicians are in doubt of the effectiveness of surgery in totally eliminating cancer cells. The treatment could also be used as a primary treatment. Patient who are inoperable and whose condition shows presence of metastasis are good candidates for radio therapy. It could also be a treatment for patients with delayed operation. The purpose might be to shrink the tumor so that it could be better handled during surgery. Preventions With the identification of the risk factors and causes of lung cancer, prevention should be focused on eliminating such causative agents. One way of convincing smokers to stop smoking is through education. They should be taught of the health risks smoking can do to the body and to other people around them. For chain smokers, technique of gradually eliminating the dependency should be presented. Individuals who were successful in this situation should be invited to share their experience on how they did it for other to follow. Although, the technique might not be applicable to all but at least smokers may realize that it could be possible to stop smoking. Non smokers may take precautions when exposed to such carcinogenic agents if it is impossible to totally remove them. Use of mask or handkerchief to cover the mouth and nose proves helpful as a preventive measure as some doctors always remind that prevention is better than cure. Works Cited Day, Rene., et al. “ Medical- surgical”. Canada’s Nursing publisher. Canada. 2007. Dockery DW, & Trichopoulos D. Risk of lung cancer from environmental exposure from tobacco smoke. Environmental Epidemiology Program. 333. May 1997. Web. 6 May 2011. Klein, F., Amin, Kotbe., & Petersen. I., “Incidence of human papilloma virus in lung cancer”. Lung cancer. 13- 8. July 2009. Web. 6 May 2011. Kocaturk, CL., et al. “Prognosis in Patients with Non-Small Cell Lung Cancer and Satellite Tumors.” Thorac Cardiovascular Surgery. 28 March 2011. Ahead of print. Web. 6 May 2011. Ma, Q., et al. “Surgical therapeutic strategy for non-small cell lung cancer with mediastinal lymph node metastasis (N2).” Zhongguo Fei Ai Za Zhi. April 2010. 13(4):342-8. Mazzone, PJ., “ Lung cancer”. The Cleveland clinic foundation. 1 . 2000. Web. 6 May 2011. National Lung Screening Trial Research Team. “The National Lung Screening Trial: Overview and Study Design”. Radiology. 143. January 2011. Web. 6 May 2011. Pastorino, U., “Lung cancer screening”. British Journal of Cancer. 102. April 2010. Web. 6 May 2011. Samet, JM., “ Radon and lung cancer”. Journal of national cancer Institute. 745-57. 1989. Web. 6 May 2011. Read More