Lung cancer is cancer of the trachea (windpipe), bronchus (airway) or lung air sacs (alveoli).
Lung cancer was a rare disease at the start of the 20th century, but increase in exposure to tobacco smoke and other triggers of the disease have contributed to a pandemic in the 20th and 21st centuries.
Lung cancer is now the leading cause of cancer deaths worldwide in both men and women. Survival rates vary depending on the cell type of the cancer and at what stage the disease was diagnosed. Research has shown that on average, only 12.6% of people with lung cancer are alive 5 years after diagnosis.
The most common symptoms and signs of lung cancer are:
- Weight loss
- Chest pain
- Bone pain
- Coughing up blood
- Clubbing, or swelling, of the fingers and toes
Tobacco smoke is responsible for more than 80% of all lung cancer cases. Other causes include exposure to:
- Diesel exhaust
- Air pollution
- Coal smoke
- Indoor emissions from other fuels
People with chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, head, neck or oesophageal cancer or breast cancer are also more at risk of developing the condition.
People can also have a genetic susceptibility to lung cancer and if there is a family history of the condition, they are more likely to develop the disease.
Stopping smoking is the most effective method of preventing the development of lung cancer. Attempts at reducing smoking in the Western World have been relatively successful, but more work is still needed to educate people on the harmful effects of smoking in some countries. Uniform policies on banning smoking in public places are also needed to help reduce the effects of passive smoke.
When asbestos is combined with cigarette smoking, the risk of developing lung cancer is 40 times greater. A worldwide ban on asbestos use is urgently needed to help prevent this risk.
CT scans are used to diagnose lung cancer. In 2011, The National Lung Screening Trial (NLST) in the USA demonstrated that screening with the use of low-dose CT reduced death from lung cancer by 20%.
Treatment to cure the lung cancer is not possible in up to 90% of cases because they are detected late. Experts now understand that there are different types of lung cancer. This means that treatments can be tailored according to each individual and the type of disease they have.
The main forms of treatment include surgery, chemotherapy and radiotherapy.
New techniques that are less invasive for a patient have been developed to try to remove the cancer. This includes keyhole surgery, known as video-assisted thoracic surgery (VATS). Surgery is carried out through a small incision in the skin, which is a much less serious operations than traditional surgery to remove a tumour. As it is a smaller operation, patients recover more quickly and it is possible for more patients to undergo surgery.
As patients with different types of lung cancer respond differently to surgery, it is possible to tailor chemotherapy depending on the type of tumour a person has. As experts have understood more about the biology of lung cancer, they have also been able to develop new drugs that target specific parts of the cancer. For example, tyrosine kinase inhibitors such as erlotinib or gefitinib have been found to be particularly beneficial for people with some advanced lung cancer.
Modern radiotherapy techniques have developed to reduce the damage caused to the areas surrounding the tumour. New techniques have allowed people with poor lung function, who were previously advised against radiotherapy, to receive radiotherapy.
- In 2008, there were an estimated 1.56 million new lung cancer cases worldwide, representing 12.7% of all new cancers
- More than a quarter of lung cancer cases occur in the under-60s
- Lung cancer accounts for the loss of 1.4 million disability-adjusted life-years (DALYs), which is the sum of years of potential life lost due to premature death and the years of productive life lost due to disability
- Lung cancer is the leading cause of cancer deaths worldwide, with 1.38 million in 2008
- Men are more frequently affected worldwide with 1.1 million cases in 2008, compared with 0.5 million in women
- In Europe, the overall survival rate at 5 years after diagnosis is 11.2% in men and 13.9% in women
Mortality rate for lung cancer. Data from the World Health Organization World and Europe Detailed Mortality Databases, November 2011 update
Current and Future Needs
The main area for action is, besides smoking prevention, is prolonging survival and improving the quality of life for people with lung cancer.
- Since smoking is the leading cause of lung cancer tobacco control measures such as smoking prevention and smoking cessation remain the most effective methods of reducing the incidence of lung cancer
- Smoking bans in public places are needed to help reduce the effects of passive smoke
- A worldwide ban on asbestos use is urgently required to help prevent the development of lung cancer
- New techniques that help doctors understand what stage the lung cancer has developed to are needed to help reduce hospital admissions and speed up decisions about treatment
- More research is needed to refine radiotherapy techniques and identify markers for lung cancer to ensure early diagnosis
- Screening of people who are thought to be at high risk of developing lung cancer could lead to detecting the disease at an early stage while it is still curable
- A well-organised and reliable database of lung cancer cases is needed to allow for trends to be identified and investigation at a public health level to look at differences for survival in different countries
- There needs to be an increased understanding of lung cancer in people who have never smoked