Lung Cancer : Articles

Lung cancer is cancer that begins in the lungs, the two organs found in the chest that help you breathe. The lungs are made up of areas called lobes. The right lung has three lobes; the left lung has two, so there's room for the heart. When you breathe, air goes through your nose, down your windpipe (trachea), and into the lungs where it spreads through tubes called bronchi. Most lung cancer begins in the cells that line these tubes. There are two main types of lung cancer: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer; Small cell lung cancer makes up about 20% of all lung cancer cases. If the lung cancer is made up of both types, it is called mixed small cell/large cell cancer. If the cancer started somewhere else in the body and spread to the lungs, it is called metastatic cancer to the lung.

Lung cancer is a malignant disease in which lung cells become abnormal, characterized by uncontrollable, unlimited growth. These cells can then invade nearby normal tissue and destroy organ structure, a process called "invasion." Lung cancer cells can also break down lung tissue structure and enter the bloodstream or lymphatic system and thus spreads to distant organs in other parts of the body, a process called metastasis. Clinically, lung cancer can be classified into two groups according to its cell types under microscopy: non-small cell lung cancer and small cell lung cancer. Non-small cell lung cancer includes cancers of three cell types: squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Small cell lung cancer, also called oat cell cancer, is a less common cancer that grows faster, and is more likely to spread to other parts of the body than non-small cell lung cancer. Lung cancer is a highly lethal disease in the United States and worldwide. According to Parkin et al. (1999), lung cancer was the most frequent cancer in 1990, worldwide, with 1.04 million new cases (771,800 in men and 265,100 in women). It is the most common cancer in men and the fifth most frequent cancer in women. Lung cancer is the leading cause of cancer deaths worldwide, with a total of 921,000 deaths per year (692,600 in men and 228,400 in women) in 1990. In the United States, it was estimated that 169,500 new lung cancer patients (90,700 men and 78,800 women) would be diagnosed and 157,400 (90,100 men and 67,300 women) would die of lung cancer in 2001. The five-year survival rate of lung cancer is 13.7 percent in the United States, 7.8 percent in developing countries, 7 percent in Eastern Europe, 7.9 percent in China, and 6.7 percent in India. The changes (increase or decrease) of lung cancer incidence corresponds to the alterations of prevalence of smoking in the population twenty to thirty years earlier, representing a latent period between tobacco exposure and the occurrence of lung cancer. A significant decrease in the incidence of lung and bronchus cancer in males in North America started in the late 1980s. Between 1990 and 1996 there was a 2.6 percent decline in incidence per year. Incidence rates of lung and bronchus cancer in females are stabilizing in the United States. Although the death rate from lung cancer in males is decreasing, it is increasing among females, and it has now exceeded the breast cancer death rate among females. Tobacco smoking is a major cause of lung cancer. Over 4,000 chemical compounds have been identified in the tobacco leaf. Carcinogens in tobacco smoke can damage the cells in the lungs, which may lead to the development of lung cancer. More than fifty chemical compounds in tobacco smoke have been recognized as known or probable human carcinogens, some of which may be formed during combustion (or smoking) and some which may exist naturally in tobacco. Several groups of carcinogens in tobacco smoke are related to lung cancer, including polycyclic aromatic hydrocarbons (PAHs), aromatic amines, benzene, hydrazine, and vinyl chloride. Smoking results in damage to the bronchial and lung epithelium, which leads to lung cell proliferation and finally to lung cancer. Animal studies confirm the carcinogenic potential of tobacco smoke in tissues having smoke contact: in these studies smoke exposure leads to laryngeal tumors and pulmonary adenomas. In humans, cigarette smokers have increased levels of tobacco carcinogen DNA adducts in the lung and bronchus when compared with nonsmokers. A very strong association between cigarette smoking and lung cancer has been consistently observed in studies done since the early 1950s. These studies have shown that cigarette smoking precedes lung cancer occurrence. It has been estimated that cigarette smokers have a ten-fold higher risk of lung cancer, in comparison with nonsmokers. With the increased number of cigarettes smoked per day, the risk is increased—heavy s

Lung cancer is a disease in which the cells of the lung tissues grow uncontrollably and form tumors. It is the leading cause of death from cancer among both men and women in the United States. The American Cancer Society (ACS) estimated that in 1998, at least 172,000 new cases of lung cancer were diagnosed, and that lung cancer accounted for 28% of all cancer deaths, or approximately 160,000 people. In 2002, the ACS reported that more than 150,000 Americans die from the disease every year. Only 15 percent of people with lung cancer will live five years.

Lung cancer is a disease in which the cells of the lung tissues grow uncontrollably and form tumors. It is the leading cause of death from cancer among both men and women in the United States. The American Cancer Society estimates that in 2001 at least 169,500 new cases of lung cancer will be diagnosed, and that lung cancer will account for 28% of all cancer deaths—approximately 157,400 people.

Surgery for Lung CancerSurgery can be done to both diagnose and treat lung cancer. In most cases, surgery is used if the cancer is found in an early stage.