What is Lung Cancer?
Lung cancer results from an abnormal and uncontrolled division of lung cells. It may spread to other parts of the body, including the brain.
There are two main types of lung cancer:
- Non-small cell lung cancer: This is the most common category of lung cancer, accounting for more than 80% of cases. A number of lung cancers that are considered non-small cell. The abnormal growth observed in each of these cancers tends to begin in similar cells, which look similar under a microscope. Sub-types include large cell carcinoma, squamous cell carcinoma, and adenocarcinoma.
- Small-cell lung cancer: A relatively rare but aggressive form of lung cancer, which spreads faster than those above, is small-cell lung cancer. The two key subtypes of this cancer are small cell carcinoma (oat cell cancer) and combined small cell carcinoma.
Cancer from other parts of the body can also spread to lungs, which is known as “secondary lung cancer.”
How common is lung cancer?
Lung cancer is the most common cancer worldwide. It is the number one cause of cancer-related deaths, accounting for 18.4% of all cancer deaths in 2018.
The highest incidence of lung cancer is in Asia, followed by Europe, North America, Latin America and the Caribbean, Africa, and Oceania. Mortality rates from lung cancer follow the same geographic pattern, with Asia having the highest number of deaths from lung cancer. This correlates with the biggest smoking populations also living in Asia.
About 4.3 percent of all lung cancer cases in 2018 were reported in Latin America and the Caribbean, whereas 4.6 percent of all lung-cancer-related deaths occurred in this region.
The following data was reported by the International Agency for Research on Cancer (IARC) for 2018:
Jamaica: Lung cancer in Jamaica is the 2nd most common cancer in men in terms of incidence and death rates
Barbados: Lung cancer in Barbados is the 3rd most common cancer in men in terms of incidence.
Trinidad and Tobago: Lung cancer in Trinidad and Tobago is the 2nd most common cancer in men in terms of incidence
Risk factors for lung cancer
- Smoking: Tobacco smoke is the most significant factor contributing to lung cancer, whether in the form of cigarette, cigar, pipe tobacco, or home-rolled tobacco. Tobacco smoke contains more than 7,000 chemicals, 70 of which are known to cause lung cancer. Smoking increases the risk of lung cancer twenty-fold. It is responsible for 9 out of 10 lung cancer cases in men and about 8 out of 10 cases in women. The risk increases with the number of cigarettes consumed each day and also the number of years a person smokes.
- Passive smoking: The risk of lung cancer is significantly increased in people exposed to secondhand smoke. Those inhaling air where a person is smoking, are inhaling the same toxic chemicals.
- Personal or family history: Someone whose first-degree relative (mother, father, sibling) has had lung cancer is twice as likely to have it compared to people who do not have a family history of lung cancer. Moreover, a person who had lung cancer has a greater chance of developing it again. This is especially true if the person smokes.
- Radiation: Exposure to radiation increases a person’s risk of developing lung cancer. Sources of radiation may include radiation therapy, especially in the chest region, high-dose CT scans, atomic bomb radiations, and Radon (a radioactive gas that comes from rocks and soil as a result of uranium breakdown). Studies show that the greater the exposure to radiation, the greater the risk of lung cancer. High levels of radon gas in the home or work environment increases the cases of lung cancer. The risk is higher in people who smoke and are also exposed to radon than non-smokers who are exposed to it.
- Asbestos and other substances: Research has discovered that people who are exposed to the following substance have a greater risk of developing lung cancer:
- Tar and soot
- Air pollution
The risk is even greater in people who smoke and are also exposed to these substances.
- HIV infection: Individuals with human immunodeficiency virus (HIV) infection have two times greater risk of developing lung cancer than those without HIV infection.
- Tuberculosis: Tuberculosis (TB) infection can increase the risk of lung cancer. The chronic inflammation that comes with TB makes our cells more susceptible to cancer formation.
Individuals who smoke are up to 30 times more likely to get lung cancer than non-smokers. Smokers can reduce their risk if they quit smoking. They can also lower the risk of those around them who are exposed to secondhand smoke. Some studies also suggest that a healthy diet and physical activity can lower the risk of lung cancer. Though evidence is still emerging it is desirable to adopt these lifestyle changes for countless health benefits and preventive effects.