Lung Cancer Causes and Types

As previously mentioned, cigarette smoking is the number one cause of lung cancer. Exposure to secondhand smoke, asbestos and other industrial carcinogens, and high concentrations of radon are other potential causes of lung cancer. In particular, smokers who experience exposure to asbestos or radon are even more at risk for cancer than nonsmokers.

A cancer is named by the body part in which it originated. So even if a nonsmoker has cancer in the kidney that spreads (metastasizes) to the lungs, it is considered metastatic kidney cancer. Nonsmokers rarely get lung cancer, and smoking does not affect the spread of cancer from other body parts to the lungs.

Of cancers originating in the lungs, there are two main types: small cell and non-small cell. Small cell cancer afflicts smokers almost exclusively, and spreads early on during the course of the disease. This type of cancer is typically treated with chemotherapy and radiation, as surgery is generally not an option. However, the five-year survival rate is very low. 

More than 75 percent of lung cancers are non-small cell. The four main types of non-small cell cancer are squamous cell carcinoma, adenocarcinoma, large cell carcinoma, and bronchoaveolar carcinoma. If caught early in the course of the disease, non-small cell cancer can often be surgically removed. Adenocarcinoma is common for nonsmokers and people exposed to secondhand smoke. On the other hand, bronchoaveolar carcinoma tends to occur more often in smokers and in more than one location simultaneously.

Lung Cancer Causes and Types

Conclusion

Causing nearly 90 percent of lung cancer cases, smoking is by far the greatest risk factor for this disease. However a decade after quitting, your risk of lung cancer is reduced by one-third. Reducing the number of cigarettes smoked can also reduce the risk, although it is not nearly as effective as quitting entirely.