Lung Cancer

• Lung Cancer
• Symptoms
• Risk Factors
• Diagnostic Procedures
• Treatment
• Research

What is Lung Cancer?

Lung cancer is cancer that usually 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. It is the leading cause of cancer death in both men and women. In 2005, 172,570 new cases of lung cancer are expected, according to the American Cancer Society.

Lung cancers are believed to develop over a period of many years.

Nearly all lung cancers are carcinomas, a cancer that begins 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. More than 95 percent of lung cancers belong to the group called bronchogenic carcinoma.

Lung cancers are generally divided into two types:

• Nonsmall cell lung cancer is more common than small cell lung cancer. The three main kinds of nonsmall cell lung cancer are named for the type of cells in the tumor:
  • Squamous cell carcinoma, also called epidermoid carcinoma, is the most common type of lung cancer in men. It often begins in the bronchi and usually does not spread as quickly as other types of lung cancer.
  • Adenocarcinoma usually begins along the outer edges of the lungs and under the lining of the bronchi. It is the most common type of lung cancer in women and in people who have never smoked.
  • Large cell carcinomas are a group of cancers with large, abnormal-looking cells. These tumors usually begin along the outer edges of the lungs.
• 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.

It is important to find out what kind of lung cancer a person has. The different types of carcinomas, involving different regions of the lung, may cause different symptoms and are treated differently.