Lung cancer is a neoplasm that originates in lung tissue. It is the most frequent carcinoma in the world, affecting men and women equally. The main risk factor is tobacco, which is responsible for 80% of the cases. Early diagnosis of lung cancer is the main condition for its successful treatment.
Lung cancer
Lung cancer accounts for almost 12% of all carcinomas diagnosed worldwide. The main cause of the development of lung cancer is smoking. It is estimated that around 80% of cases are caused by smoking and many of the remainder by exposure to tobacco smoke.
Smoking is undoubtedly the main risk factor for lung cancer, although others have also been identified that may contribute:
- Time and number of cigarettes. The risk of lung cancer increases the more and longer cigarettes are smoked.
- Passive exposure to tobacco smoke.
- Exposure to radon, a radioactive gas that accumulates inside some homes and workplaces. It is estimated to be responsible for between 3-14% of lung cancer cases.
- Exposure to asbestos
- Environmental contamination. Some studies suggest that pollution in large cities may increase the risk of lung cancer.

Symptoms
In the early stages, lung cancer does not usually show symptoms. These appear when the cancer is more advanced, making its prognosis poor. The most characteristic signs and symptoms are:
- Persistent cough with blood.
- Shortness of breath.
- Chest pain.
- Hoarseness.
- Weight loss without apparent cause.
- Bone and joint pain.
- Headache.
- Inflammation in the neck and face.
Prevention
Lung cancer is the leading cause of death in the world. Although it is not totally preventable, its risk can be effectively reduced by a series of measures.
- Avoid exposure to tobacco. Not smoking and avoiding exposure to tobacco smoke is the most effective measure to reduce the risk of lung cancer.
- Avoid exposure to radon or asbestos, chemicals directly related to lung cancer.
- Healthy lifestyle, with a balanced diet rich in fruits and vegetables and regular physical exercise.
Number of observed variants
13.5 million variants
Number of risk loci
21 loci
Genes analyzed
Bibliography
Mao Y, Yang D, He J, Krasna MJ. Epidemiology of Lung Cancer. Surg Oncol Clin N Am. 2016 Jul;25(3):439-45.