What is Lung Cancer?

Lung cancer is a growth of malignant cells in the lungs.
You see, throughout your life the cells in your body continually divide and reproduce. Believe it or not, every minute of your life this process takes place ten million times. Think about it ... ten million times a minute! Not only is that incredible, it's a demonstration of how complex your body really is.
Now, for the most part, this all takes place in an orderly manner as your cells go about doing their job of meeting the needs of your body. Occasionally, however, a cellular mutation will occur and rather than maturing and dying as it was intended to do, a cell continues reproducing. This is cancer ... the uncontrolled reproduction and growth of abnormal cells in the body.
Lung cancer is the growth of these malignant cells in the lungs.
Most often, the malignant cells are believed to form in the epithelial lining of the airways, where the oxygen is extracted from the air we breathe. This is why lung cancer is sometimes referred to as bronchogenic carcinoma (cancer arising from the bronchia). A relatively small percentage of lung cancer (10% or less) begins in the pleura, the thin tissue sac that surrounds the lungs. These cancers are called mesothelioma. The most common form of mesothelioma is linked to exposure to asbestos. The rarest form of begins in the blood vessels or other supporting tissues of the lungs.
Types of Lung Cancer
There are two main types - small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).
SCLC is the less common of the two, which is good, because it's also the more deadly. Less than one percent of SCLC is diagnosed in non-smokers. This means that smoking is the primary culprit behind this type of lung cancer. SCLC is aggressive and fast-moving. It rapidly metastasizes to other organs, and is often not discovered until the cancer is already widespread throughout the body.
Non-small cell lung cancer accounts for approximately 80% of diagnosed lung cancer cases. Within this category, there are three main sub-categories ... squamous cell cancer, adenocarcinomas, and large cell carcinomas. Sometimes two or even all three can appear together.
Finally, there are some less common types such as bronchial carcinoids (small tumors that are most often found in people under 40 years of age). These tend to be less aggressive, grow slowly, and often can be effectively treated.
A Deadly Cancer
Cancer of the lungs is one of the deadliest forms of cancer. This is primarily due to the fact that lung cancer tends to metastasize early in the process of the disease and is often not discovered until it's spread. Additionally, when it does metastasize, it tends to spread to the most vital yet vulnerable organs of the body. The adrenal glands, the liver, the brain and the bones are all early targets.
Finally, because the lungs are so susceptible to metastatic cancers from other sources throughout the body, it's not uncommon to find a cancer in the lungs that is not lung cancer but a metastatic cancer. These cancers tend to make their home in the peripheral tissues of the lungs rather than the primary tissues.