The lungs are two large organs made of spongy tissue, which lie above the diaphragm and under the rib cage. When you breathe in, your lungs absorb oxygen and deliver it to the bloodstream where it’s pumped throughout the body. When you exhale, the lungs remove carbon dioxide, a waste gas, from the bloodstream. Lung cancer interferes with this vital process and can make breathing more difficult. Lung cancer is the second-most diagnosed cancer among both men and women. Smoking significantly increases a person’s chance of developing the disease, but people who have never smoked may develop lung cancer, too.
According to the National Cancer Institute, one out of every 14 Americans will be diagnosed with lung or airway cancer in their lifetime. In 2009, there were more than 219,000 people diagnosed with lung cancer in the United States.
There are two main types of lung cancer: small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). Each one is distinguished by the appearance of cells under a microscope, and how fast they spread in the body.
Non-small cell lung cancers account for nearly 80 percent of lung cancers and spread more slowly in the body. There are three lung cancer types listed under the non-small cell lung cancer umbrella:
Adenocarcinoma is generally found in the mucus-producing glands of the lung. When it develops in the lung’s alveoli (tiny lung sacs), it is referred to as bronchioalveolar adenocarcinoma.
Squamous cell carcinoma typically originates in the lung’s large breathing tubes (bronchi) and is closely linked to cigarette smoking.
Large cell carcinoma usually begins in the branches of the smaller breathing tubes (bronchioles). This type of lung cancer may migrate towards an area behind the breastbone called the mediastinum, which houses the esophagus, windpipe, bronchi and heart.
Small cell lung cancers account for approximately 20 percent of lung cancers. They typically begin in the lung’s bronchi and spread quickly, often to other parts of the body. Small cell lung cancer is sometimes called oat cell cancer because of its oat grain-like shape when viewed under a microscope.
Metastatic lung cancer is cancer that has spread to other parts of the body.
There are also rarer lung cancer types, including bronchial carcinoids and cancers that start in other parts of the lung.