Lung cancer kills more people than any other type of cancer.10 According to the American Cancer Society; there were 215,020 new cases of lung cancer and 161,840 deaths expected due to lung cancer in the United States in 2008. I know how lethal this cancer can be. I was 15 years old when the Surgeon General, Luther Terry, in 1964 announced that cigarette smoking could cause lung cancer.13 I came from a family of smokers, my parents as well as my grandmother who lived with us smoked. Everyone I knew smoked including most of my classsmates. By 16 I was smoking to be “sophisticated and adult”. In my early 20s, I developed asthma which forced me to quit. It was a blessing in disguise. My father was not so lucky. He quit smoking in the early 90s due to a heart attack and did quite well until he developed a nagging pain in his side. It was a shock to learn he had small cell lung cancer that had metastasized to the liver. The oncologist advised with chemotherapy he could prolong his life, with quality of life – for about seven months. Without it, he would be dead in two. Although he sailed through chemotherapy, two months afterwards he had a stroke. The cancer had spread to his brain. Treated then with radiation, he lived another four months. My father became another lung cancer statistic.
There was hardly any reference to lung cancer prior to the nineteenth century. The use of tobacco in the 1800s was primarily cigar use by wealthy gentlemen; cigarettes were made of the leftover cigar scrapings and smoked by the poor. 19 It wasn’t until World War I when cigarettes were mass produced and given away free to millions of soldiers by tobacco companies that cigarettes became popular. Because of the time lag of about 20 to 30 years between starting to smoke and lung cancer development, it wasn’t until the 1930s that suddenly there was an increase in the cases of lung cancers. 19
In the 1950s studies in the United States and in England proved the association between smoking and lung cancer. 10 However, cigarette smoking was, by then, a way of life. The rich and famous, the sophisticated and attractive, all smoked. Macho men such as The Marlboro Man, John Wayne, Yul Brynner, Jason Robards, Paul Newman and a huge number of Hollywood actors, entertainers such as Nat King Cole, TV broadcasters such as Edward R. Murrow, and even Walt Disney, all smoked. Old movies from the 40s and 50s almost always showed actors smoking. Women started smoking as well during World War II in part to huge marketing campaigns by the tobacco companies. Lung cancer went from hardly been heard of, to the number one cancer killer in the Western world by the 1970s.19
By the 1990s the public was made aware of the methods that some tobacco companies used to making cigarettes even more addicting. 9 Of the above mentioned actors (including three who appeared in the Marlboro commercials as the Marlboro Man), all died of lung cancer. 10, 7, 20, 11, 14 Yul Brynner made a very profound commercial against smoking which aired in the 1980s shortly after his death.
Lung cancer begins in the tissues of the lungs and is primarily caused by cigarette smoking. It is responsible for about 85-95% of all lung cancer deaths and is primarily a disease of the elderly usually over the age of 65. 9, 16 There are over 4,000 chemical compounds in tobacco smoke. There are two primary carcinogens, nitrosamines and polycyclic aromatic hydrocarbons, as well as many other carcinogenic compounds. Smoking one pack of cigarettes a day increases the risk of developing lung cancer that is 25 times that of a nonsmoker and the risk increases by the number of years smoked. Cigar and pipe smoking can also cause lung cancer and the risk of developing cancer is about 5 times that of a non tobacco user. 16
Radon gas is a natural radioactive gas that is the second leading cause of lung cancer among non-smokers and is responsible for about 21,000 lung cancer deaths each year. Radon gas can travel through pipes, foundation gaps, or other openings into homes. It is invisible, and undetectable by smell or taste. One out of every 15 homes can contain lethal levels of radon gas per the Environmental Protection Agency. This gas can be detected with simple testing kits. 13
Secondhand smoke, inhaling the smoke from tobacco users, is another cause of lung cancer. There is a 24% increased risk for developing lung cancer in a nonsmoker who resides with a smoker. 16
Occupational hazards, such as asbestos exposure, can cause cancer although the use of asbestos today has been banned or very limited. Asbestos fibers can last permanently in the lungs after exposure, and smoking vastly increases the risk of lung cancer to as much as 50 to 90 times that of nonsmokers. 16
Environmental causes, the smallest percent of lung cancer deaths at 1%, can be attributed to air pollution. Whether industrial, vehicle, power plants, etc, the prolonged exposure to air pollution can carry a risk similar to that of secondhand smoke. 16
Genetically there is also a predisposition in some people to the development of lung cancer as well, those people with a relative who has had lung cancer are more likely to develop lung cancer, regardless of whether they smoke or not. There is also recent research that has determined a chromosome that likely contains a gene that increases the chance for development of lung cancer in smokers. 16
The symptoms of lung cancer often are similar to other respiratory disorders and can make early detection very difficult in a smoker. A chronic cough, shortness of breath, coughing up blood, chest pain or back pain, a new cough, wheezing, decrease in exercise capacity, pneumonia or repeated respiratory infections all can be signs of lung cancer. These symptoms are caused by the effects of the tumor or possible disturbances of blood or hormones. 17
There can be other symptoms that can be caused by the tumor’s effect due to metastasis to other organs in the body. Some of the more common symptoms can be bone pain, joint pain, vision problems, hoarseness, seizures, weakness, fatigue, chills, clubbing, atrophy, loss of appetite and weight loss. It is estimated that 1/4 of people with lung cancer will not have any symptoms until the cancer has been diagnosed by other means, such as a chest x-ray. 22
Classes of Lung Cancer:
Lung cancer is a disease of uncontrolled cell growth in the lung tissues. It is divided into two classes and further divided by histological appearance, non small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). The classifications determine the treatment and the prognostic factors. 6
The most common type of lung cancer is NSCLC. It makes up approximately 80% of all lung cancer cases. It is divided into three main categories. The two most common types of non-small cell lung cancer are adenocarcinoma (ADC) and squamous cell carcinoma (SCC). ADC originates in the cells that are in the lining of the lungs and is the most common type in non-smokers. It can be histologically sub classified further into bronchioloalverolar (BAC), papillary, acinar, mixed and solid with mucin carcinomas.4 SCC originates in the cells that line the passages of the respiratory tract. There is an additional third type called large-cell carcinoma (LCC) or large-cell undifferentiated carcinoma which makes up a group of cancers which have variants including clear cell carcinoma, giant cell carcinoma, and large cell neuroendocrine carcinoma (LCNEC). 4, 14 These cancers are somewhat slow growing as opposed to the SCLC. NSCLC usually starts in the bronchi/lung lining but it can also start in other parts of the lungs, and commonly spreads to the mediastinum and the lymph nodes. It can take years sometimes, for NSCLC to develop to the point where it is symptomatic.
SCLC, on the other hand, is the most aggressive of the lung cancers, making up about 20% of all lung cancer cases. 15 The statistics for survival are low – only a 5-year survival rate. SCLC is considered a neuroendocrine tumor and is subdivided into three classes which are small cell carcinoma (oat cell cancer) the most common, mixed small cell/large cell carcinoma, and combined small cell carcinoma. It usually originates in the central airways; the lobar or main bronchi and lymph nodes are involved very early in the disease process. 5 This is a particularly lethal cancer that grows extremely rapidly. Usually no symptoms are ever indicated until there is already metastasis to another organ site. The course, treatment and prognosis are much different from LSCLC as it is considered a systemic disease. 5
Last to mention are the carcinoid tumors, which recently have been discovered to be a form of bronchopulmonary neuroendocrine tumors which include SCLC but not as lethal. These are fairly uncommon pulmonary neoplasms; typical carcinoid tumors grow slowly and metastasis is rare, atypical carcinoid tumors are much more aggressive. Approximately 1 to 6% of lung carcinomas are carcinoid. 5
There are several additional rare forms of cancer that can occur in the lung such as adenoid cystic carcinoma and mucoepidermoid carcinoma, but these are primarily salivary gland tumors. 6 Read More +