Sylvester Comprehensive Cancer Center

Education: Lung Cancer

Chest and upper body

Lung cancer typically starts in the lining of the bronchi (the main airways of the lungs), but can also begin in other areas of the respiratory system, including the trachea, bronchioles, or alveoli. According to the American Cancer Society, more than 220,000 new cases are diagnosed in the U.S. each year. Lung cancer is the second most common cancer and the leading cause of cancer death in both men and women. However, according to the National Cancer Institute, the death rate from lung cancer continues to decrease among white and black men, while the rate of increase has slowed among women, reflecting reductions in tobacco smoking.

Lung cancer is believed to develop over a period of many years. Nearly all lung cancers are carcinomas (cancers that begin in the lining or covering tissues of an organ). The tumor cells of each type of lung cancer grow and spread differently, and each type requires different treatment.

Lung cancers are generally divided into two types, non-small cell lung cancer and small cell lung cancer. There are three main types of non-small cell lung cancer (squamous cell carcinoma, adenocarcinoma and large-cell undifferentiated carcinoma), named for the type of cells found in the tumor. Small cell lung cancer, sometimes called oat cell cancer because the cancer cells may look like oats when viewed under a microscope, grows rapidly and quickly spreads to other organs. Non-small cell lung cancer is more common than small cell lung cancer.

Risk Factors

A risk factor is anything that increases a person’s chance of developing a disease such as cancer. Different cancers have different risk factors. Several risk factors make a person more likely to develop lung cancer.

Smoking is the leading risk factor for lung cancer. According to the American Cancer Society, tobacco smoke causes more than eight out of 10 cases of lung cancer. Other risk factors include:

  • Exposure to second-hand smoke
  • Smoking marijuana
  • A personal and/or family history of lung cancer
  • A disease, such as tuberculosis and some types of pneumonia, that leaves scars on the lung
  • Exposure to asbestos or industrial grade talc
  • Exposure to cancer-causing agents in the workplace, such as uranium and other radioactive ores, arsenic, vinyl chloride, coal products, and certain fuels
  • Exposure to radon, a radioactive gas with no color, taste, or smell
  • Exposure to air pollution

These factors do not necessarily cause lung cancer.