Lung cancer is “the uncontrolled growth of abnormal cells in one or both lungs”. These abnormal cells do not carry out the functions of normal lung cells and do not develop into healthy lung tissue. As they grow, “the abnormal cells can form tumors and interfere with the functioning of the lung, which provides oxygen to the body via the blood”. There are two major types of lung cancer, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Staging lung cancer is based on whether the cancer is local or has spread from the lungs to the lymph nodes or other organs.
Because the lungs are large, tumors can grow in them for a long time before they are found. Even when symptoms—such as coughing and fatigue—do occur, people think they are due to other causes. For this reason, “early-stage lung cancer (stages I and II) is difficult to detect. Most people with lung cancer are diagnosed at stages III and IV. Non-small cell lung cancer accounts for about 85 percent of lung cancers”(Lung Cancer 101. ). The most common form is called Adenocarcinoma. Disease history.
Hanspeter Witschi, a journalist from ITEH and Department of Molecular Biosciences, said, “a hundred years ago, lung cancer was a reportable disease, and it is now the commonest cause of death from cancer in both men and women in the developed world, and before long, will reach that level in the developing world as well. Lung cancer continues to be the leading cause of death in both men and women in the US, with over 158,900 deaths in 1999. Worldwide, lung cancer kills over 1 million people a year.
The disease has no particular symptoms or signs for its detection at an early stage. Most patients therefore present with advanced stage IIIB or IV disease” (Witschi, H. ). “Screening tests began in the 1950s with annual chest x-ray films and sputum cytology but they resulted in no improvement in overall mortality compared with control subjects. The same question is now being asked of spiral low-dose computed tomographic scanning. There have been big refinements in the staging classification of lung cancer and advances in stage identification using minimally invasive technology.
Postsurgical mortality has declined from the early days of the 1950s but 5-year cure rates have only barely improved. The addition of chemotherapy to radical radiotherapy, together with novel radiotherapy techniques, is gradually improving the outcome for locally advanced, inoperable non–small cell lung cancer. In 1912, Adler published a book entitled Primary Malignant Growths of the Lungs and Bronchi, where he reported all cases of lung cancer in the published literature worldwide.
He could verify only 374 cases. Smoking was popularized during the First World War. Today, in the United States, the combined annual number of deaths from breast, colon, and prostate cancer would not equal the death toll from lung cancer, and last year more than 150,000 patients died of this disease. It represents the most preventable respiratory disease worldwide and, while its incidence is decreasing in the developed world, an epidemic of untold proportions is unfolding in the developing countries.
Advances in imaging, diagnosis, staging, and treatment have come relatively recently, but despite our best efforts, the 5-year survival for this disease remains a dismal 16% in the United States and 5% in the United Kingdom” (Spiro, S. G. , & Silvestri, G. A. ). Cause Adenocarcinoma of the lung is a type of lung cancer. It occurs when abnormal lung cells multiply out of control and form a tumor. Eventually, tumor cells can spread to other parts of the body including the lymph nodes around and between the lungs, liver, bones, adrenal glands, and the brain.
Compared with other types of lung cancer, Adenocarcinoma is more likely to be contained in one area. If it is truly localized, it may respond to treatment better than other lung cancers. It’s generally found in smokers. However, it is the most common type of lung cancer in nonsmokers. It is also the most common form of lung cancer in women and people younger than 45. As with other forms of lung cancer, your risk of Adenocarcinoma increases if you smoke. “Smoking cigarettes is by far the leading risk factor for lung cancer. In fact, cigarette smokers are 13 times more likely to develop lung cancer than nonsmokers.
Cigar and pipe smoking are almost as likely to cause lung cancer as cigarette smoking. As well as breathing tobacco smoke, nonsmokers who inhale fumes from cigarette, cigar, and pipe smoking have an increased risk of lung cancer. Those who are exposed to radon gas are prone to the inhabitance of Adenocarcinoma. Radon is a colorless, odorless radioactive gas formed in the ground. It seeps into the lower floors of homes and other buildings and can contaminate drinking water. Radon exposure is the second leading cause of lung cancer”(Adenocarcinoma of the Lung).
It’s not clear whether elevated radon levels contribute to lung cancer in nonsmokers. But radon exposure does contribute to increased rates of lung cancer in smokers and in people who regularly breathe high amounts of the gas . “Those who are exposed to asbestos are also prone to this type of lung cancer. Asbestos is a mineral used in insulation, fireproofing materials, floor and ceiling tiles, automobile brake linings, and other products. People exposed to asbestos on the job (miners, construction workers, shipyard workers, and some auto mechanics) have a higher-than-normal risk of lung cancer.
People who live or work in buildings with asbestos-containing materials that are deteriorating also have an increased risk of lung cancer. In addition to having a higher risk of Adenocarcinoma, people who have been exposed to asbestos have a greater risk of developing Mesothelioma”. This is a type of cancer that starts in the tissue surrounding the lungs. Treatment Treatment depends on the cancer’s stage as well as the patient’s condition, lung function, and other factors. If the cancer has not spread, surgery is the best treatment. There are three types of surgery.
Wedge resection surgery removes a only a small part of the lung, lobectomy removes one lobe of the lung and pnuemonectomy removes the entire lung. Because surgery will remove part or all of a lung, breathing may be more difficult afterwards, especially in patients with other lung conditions. Doctors can test lung function prior to surgery and predict how it might be affected by surgery. Depending on how far the cancer has spread, treatment may include chemotherapy and radiation therapy. These may be given before and/or after surgery.
When the tumor has spread significantly, chemotherapy may be recommended to slow its growth, even if it cannot cure the disease. Chemotherapy has been shown to ease symptoms and prolong life in cases of advanced lung cancer. “Chemotherapy offers modest survival improvement for patients with non–small cell lung cancer, the modern agents being better tolerated resulting in an improved quality of life” (Witschi,H. ) Radiation therapy can relieve symptoms, too. It is often used to treat lung cancer that has spread to the brain or bones and is causing pain.
It can also be used alone or with chemotherapy to treat the lung cancer that is confined to the chest. People who may not withstand surgery due to other serious medical problems may receive radiation therapy, with or without chemotherapy, to shrink the tumor. Medications One of the most exciting developments in lung cancer medicine is the introduction of targeted treatments. Unlike chemotherapy drugs, which cannot tell the difference between normal cells and cancer cells, targeted therapies are designed specifically to attack cancer cells by attaching to or blocking targets that appear on the surfaces of those cells.
People who have advanced lung cancer with certain molecular biomarkers may receive treatment with a targeted drug alone or in combination with chemotherapy. These treatments for lung cancer include Erlotinib (Tarceva), Bevacizumab (Avastin), and Crizotinib (Xalkori). “A targeted treatment called erlotinib has been shown to benefit some people with non-small cell lung cancer. This drug blocks a specific kind of receptor on the cell surface—the epidermal growth factor receptor (EGFR). Receptors such as EGFR act as doorways by allowing substances in that they can encourage a cancer cell to grow and spread.
Lung cancer cells that have a mutation on the EGFR are likely to respond to treatment with erlotinib instead of chemotherapy. For patients who have received chemotherapy, and are in need of additional treatment, erlotinib can be used even without the presence of the mutation. Just like normal tissues, tumors need a blood supply to survive. Blood vessels grow in several ways. One way is through the presence of a substance called vascular endothelial growth factor (VEGF). This substance stimulates blood vessels to penetrate tumors and supply oxygen, minerals, and other nutrients to feed the tumor.
When tumors spread throughout the body, they release VEGF to create new blood vessels. Bevacizumab works by stopping VEGF from stimulating the growth of new blood vessels. When combined with chemotherapy, bevacizumab has been shown to improve survival in people with certain types of non-small lung cancer, such as adenocarcinoma and large cell carcinoma. Crizotinib is a newly available treatment that has shown benefits for people with advanced non–small cell lung cancer who have the ALK biomarker. Mutations in the way cells program ALK result in changes to the way it functions, leading to increased tumor cell growth.
Crizotinib works by blocking ALK and stopping the growth of the tumor” (Lung Cancer 101). Prognosis The outlook depends on the cancer’s stage and the patient’s overall health. In general, the prognosis is poor, especially if the lung cancer has spread beyond the chest or has invaded lymph nodes between the lungs. “Adenocarcinoma of the lung can only be cured if the entire tumor is removed surgically or destroyed with radiation”. However, many lung cancers are diagnosed at a stage when this is not possible. “Less than one-fifth of patients survive five years or longer”(Adenocarcinoma of the Lung). References Adenocarcinoma of the Lung.
(n. d. ). Retrieved December 4, 2013, from Drugs website: http://www. drugs. com/health-guide/adenocarcinoma-of-the-lung. html Lung Cancer 101. (n. d. ).
Retrieved December 5, 2013, from Lung Cancer website: http://www. lungcancer. org/find_information/publications/163-lung_cancer_101/265-what_is_lung_cancer Spiro, S. G. , & Silvestri, G. A. (2005). One Hundred Years of Lung Cancer. American Journal of Respiratory and Critical Care Medicine, 172(5), 523-529. http://dx. doi. org/10. 1164/rccm. 200504-531OE Witschi, H. (2001). A Short History of Lung Cancer. Toxicological Sciences, 64(1), 4-6. http://dx. doi. org/10. 1093/toxsci/64. 1. 4.