Lung cancer is the most common cause of death from cancer for men and women around the world. For 2009, the American Cancer Society has estimated that there was almost 220,000 new cases of lung cancer and just over 159,000 deaths as a result of the disease. To put this in perspective, it is thought that on in fourteen people will develop cancer of the lungs in their lifetime. Today, in America, lung cancer deaths are more prevalent than breast cancer fatalities amongst women.
While this may sound depressing, it should be borne in mind that people tend to control their risk factors for the disease by making lifestyle choices. It would be surprising if any reader is not aware that smoking dramatically increases the risk of contracting the disease, nor that passive smoking is linked to increased incidence of lung cancer amongst those who do not smoke.
Nevertheless, the incidence of lung cancer is primarily constrained to the elderly, i.e. those over the age of 65 years. Lung cancer is rarely found in patients under the age of 45 (less than 3%), and more than 70% are over 65.
The incidence of lung cancer rose dramatically from the 1930’s as tobacco smoking took hold and became fashionable and socially acceptable. On a global basis, it can be seen that lung cancer rises where anti-smoking education is not practised, however, where countries implement smoker awareness campaigns and it becomes recognized that smoking is a major factor in disposition for contracting the disease.
What Are the Causes of Lung Cancer?
Smoking and lung cancer are very closely related, and indeed it is thought that 90% of lung cancers are caused because the patient smoked or is smoking. Research indicates that continuing to smoke tobacco increases the incidence of the disease and stopping smoking, even for as little as a year, can dramatically reduce the relative risk of contracting the condition.
The greater the usage of tobacco, the greater the risk of contracting lung cancer and the there is a direct correlation between the total amount of tobacco smoked and the disease,. Someone who smokes 10 cigarettes a day for 20 years has the same risk as someone who smokes 20 cigarettes a day for 10 years.
More poignantly, those who smoke more than 2 packs of cigarettes a day, one in seven will die from the disease. The culprit is in the constituents of tobacco smoke, with more than 4,000 chemical compounds amongst which, many are known as carcinogens, i.e. cancer causing compounds.
A common question is how long does a smoker have to quit smoking before their risk levels return to those of a non-smoker? The answer seems to be that a smoker needs to have ceased smoking for approximately 15 years for them to have the same low level of risk as someone who has never smoked.
Passive smoking has also been linked to lung cancer and this is where a patient has been inhaling second-hand cigarette smoke from a smoker. Non-smokers who live with a smoker experience an increase in their risk profile of almost a quarter, and in the US annually, some 3,000 people die as a result of second-hand smoke.
Smoking may be the primary cause of lung cancer deaths, however it is not the only cause. Exposure to asbestos and radon gas are also linked with increased risk of contracting lung cancer. There is also the genetic predisposition of patients for contracting the disease which plays a clear role, though how this operates in practice is not clearly understood.