Lung cancer is a leading cause of death all over the world. In fact death from lung cancer even exceeds the number of death caused from other cancers combined together which include breast, prostate, pancreas and colon. We all know smoking is the biggest risk factor for development of lung cancer. But very less people realize lung cancer can also occur in never smokers. According to an estimate at least 25 percent of lung cancer develops in non smokers.
Although lung cancer in smokers and non smokers is considered together as same while discussing cancer of lungs, there are several differences.For example two thirds of women who suffer from lung cancer are non smokers. There are many woman who have nerve smoked in their life develop lung cancer. The number of women in such category is more among those of Asian origin.
People developing lung cancer at younger age are usually non smokers. The genetic mutation of lung cancer in people who do not smoke is different from that of people who smoke. This is why the medicines act well in non smoker having lung cancer. They usually live longer than those who have developed cancer of lung because of smoking.
Main Causes Of Lung Cancer In Nonsmokers
Here are some important causes that are related to lung cancer in non smokers:
- Secondhand smoke: At least 30 percent of lung cancer in non smokers is caused due to secondhand smoke. Some people refer it as passive smoking. People who remain near smokers and inhale smoke released by smokers are vulnerable to many lung problems which also includes lung cancer.
- Exposure to radon gas in houses is the main cause for lung cancer in people who are not smoking. Radon is a natural radioactive gas which is present in the environment when uranium in the soil breaks down. The gas has no odor, taste and is invisible. Normally radon spreads in the environment and is not a concern. But if it gets accumulated in the home and its concentration is high, people who get exposed to it for long time can have many health risks which also include lung cancer.
- Lung cancer can be related to people working in certain occupations. It can be an occupational hazard even if a person is non smoker. If a person is exposed to carcinogens for long duration he is susceptible to develop lung cancer. People working in asbestos factories, those dealing and handling regularly with silica, arsenic, and pesticides are at risk of suffering from lung cancer.
- Air pollution is another important cause for lung cancer. Air pollution can occur from power plants, motor vehicle exhaust, wood stoves, etc.
- Radiation therapy for breast cancer or for Hodgkin’s disease can increase the risk of lung cancer even if the patient is a non smoker.
- Lung cancer also has an underlying genetic disposition. A non smoker having family history of lung cancer is more vulnerable to develop this dreaded disease.
How Is Lung Cancer Different In Non-Smokers?
Majority of lung cancer in smokers is squamous cell lung cancer. Most non smokers suffering from lung cancer are of adenocarcinoma type. Both these forms of lung cancer are non- small cell lung cancer. The cancerous tumor in smokers is usually present near the bronchi. Cough and blood in sputum are its common symptom.
The symptoms of lung cancer in non smokers develop very late. The tumor usually grows in the outer area of lung. Symptoms include breathing difficulty and fatigue in its early stage. Various other symptoms may develop if the cancer spreads to other parts of the body such as the bones, brain, liver etc.
Lung cancer in non smokers has various differences than lung cancer in smokers at molecular and genetic level. However, treatment for both these cancer remains similar. Chemotherapy, radiation and targeted therapy are few treatments.
In some cases surgery is indicated if the cancer is detected in its very early stage before it has spread to other organs. The survival of patients with lung cancer who do not smoke is slightly better than lung cancer in smokers.