What is lung cancer?
Lung cancer is a collective name for a number of malignant tumors arising in the lungs. The main types are:
- Bronchial
- Squamous cell lung cancer
- Adenocarcinoma
- Large cell undifferentiated carcinoma
The mesothelioma is not cancer but a tumor of the pleura. This occurs especially after exposure (decades earlier) to asbestos. In addition, is found in the lungs often tumors that have spread to other places, for example, prostate or breast cancer. A Pancoast tumor is a form of cancer where the tumor is located high in the Longtop. The term Pancoast tumor says nothing about the type of lung cancer, but only on where the tumor is located.
Only a small percentage (less than 25%) of patients with lung cancer being considered for surgery. This is to remove a portion of a lung or an entire lung. Often, surgery is no longer possible because at a late stage symptoms occur. The disease is often spread to the lymph nodes or to other organs. An operation is then usually pointless.
In about half of the patients, the disease occurs after an operation within 5 years back. The outlook is generally poor. After making the diagnosis dies about 60% of the patients within one year, 80% within 2 years and 90% within 4 years. The five year survival of all types of lung cancer together is less than 10%.
In 2003, the diagnosis of lung cancer in the Netherlands was set at more than 6000 men and 3000 women. The incidence in men has decreased over the past 20 years and actually increased in women. These trends are likely explained by trends in smoking habits.
Causes of lung cancer
Active smoking
Already in the forties taught William Wassink in Dutch Journal of Medicine on smoking as a cause of lung cancer. In the fifties by other research, in particular of Sir Richard Doll, the likelihood that the main cause of lung cancer is smoking, especially cigarettes. In 87% of cases of lung cancer, smoking is the cause. Smoking is strongly increase risk. Women who smoke are about 12 times as likely to develop lung cancer as women who have never smoked. For men the risk by 22 times higher. The latency period between smoking and lung cancer has an average of twenty to thirty years. Thus, the current decline in mortality from lung cancer in men is mainly due to the decline in smoking that several decades ago has started. Also, the duration of exposure is also important. It would appear that the duration of smoking a greater risk of getting lung cancer than to have the number of cigarettes smoked. The risk decreases again when the exposure is removed (so if you stop smoking).
Passive smoking
Passive smoking is passive smoking by the smoke of cigarettes (environment) to breathe. Probably increases inhaling the smoke of others, the risk of lung cancer. People who do not smoke but are regularly exposed to secondhand smoke have probably a 20 to 30% higher risk of developing lung cancer than people who do not smoke and are not exposed to passive smoking as well as an increased risk of many other diseases.
Air pollution
Polluted air in 2013 by the International Agency for Research on Cancer (IARC) as a cause of lung cancer. Previously all diesel fumes and other components of polluted air labeled as the cause of lung cancer, but now it applies to polluted air in general. In particular, the fine particle component contributes to the increase of the risk of lung cancer.
Exposure to radon gas
Radon is a colorless and odorless gas, which is a degradation product of the radioactive radium. This product is a decay product of uranium present in the earth's crust. The radioactive decay products ionize genetic material, which ensure mutations. Sometimes mutations that lead to cancer. In the US, radon is the second highest cause of lung cancer. The risk increases by 8-16% for every 100 Bq / m³ increase in radon concentration. The level of radon gas varies greatly by region, by the composition of the soil and rocks. For example, in the United Kingdom in Cornwall radon gas is a major problem. Buildings are must be ventilated to keep the concentration of radon gas is low. According to the European Commission in the European Union die every year 20,000 people from cancer due to exposure to radon gas. That is 9% of all lung cancer deaths, and 2% of all cancer deaths. In Belgium there are elevated levels in the Walloon part of the country, mainly in the provinces of Liege and Luxembourg. According to the Federal Agency for Nuclear Control, Belgium had a yearly 700 cases of cancer due to prolonged radon exposure.
Cancer caused by asbestos
As a result of exposure to asbestos, a malignant tumor of the pleura, mesothelioma, arise. The chance of the occurrence of this type of cancer is dependent upon the duration of exposure to asbestos fibers; as exposure to asbestos fibers, the greater the chance of getting cancer of the pleura, increasing. The severity of the disease is not dependent on the degree of exposure.
In lung cancer caused by asbestos exposure we know latency of 20 to 30 years. This long latency period makes it difficult to draw conclusions about the number of cases of cancer caused by asbestos. It is estimated that asbestos related pleural mesothelioma in the Netherlands occurs about 350 times a year.
Lung cancer symptoms
The symptoms vary from patient complaints that can be caused by lung cancer are:
- Weight loss, decreased appetite
- Stuffiness
- Hoarseness
- Haemoptysis (give blood)
- Cough
- Pain
- Difficulty swallowing
- Finger clubbing thickened ends of the fingers and bulging nails (also press finger straps)
Lung cancer treatment
The most common treatments for lung cancer include:
- Surgery, in which a lobe is removed (lobectomy) or an entire lung is removed.
- Radiation (radiotherapy)
- Chemotherapy (treatment with drugs inhibiting cell division)