Lung cancer is cancer that starts in the lungs. There are two main types of lung cancer: small cell and non-small cell.
The treatment for each type of lung cancer is very different. About 10 to 15 percent of all lung cancers are small cell lung cancer (SCLC), named for the size of the cancer cells when seen under a microscope. About 85 to 90 percent of lung cancers are non-small cell lung cancer (NSCLC). There are three main subtypes of NSCLC. The cells in these subtypes differ in size, shape and chemical make-up when viewed under a microscope. Be sure to ask your doctor which type of lung cancer you or your loved one has.
The lungs are two sponge-like organs in the chest. Their main function is taking in oxygen and getting rid of carbon dioxide. When you breathe in, air enters through your mouth and nose and goes into your lungs through your windpipe. Your windpipe divides into tubes called the bronchi (just one is called a bronchus), which divide into smaller branches called the bronchioles. At the end of the bronchioles are tiny air sacs known as alveoli. A thin lining called the pleura surrounds the lungs. The pleura protects your lungs and helps them slide back and forth against the chest wall as they expand and contract during breathing. Below the lungs, a dome-shaped muscle called the diaphragm separates the chest from the abdomen. When you breathe, the diaphragm moves up and down, forcing air in and out of the lungs.
Small cell lung cancers start in the cells lining the bronchi and in other parts of the lung such as the bronchioles or alveoli. As a cancer develops, the cancer cells may make chemicals that cause new blood vessels to form nearby, nourishing the cancer cells until they grow into a tumor large enough to be seen on imaging tests such as x-rays. At some point, cells from the cancer may break away from the original tumor and spread to other parts of the body. Lung cancer is often a life-threatening disease because it tends to spread in this way even before it can be detected in x-rays or other tests.
Lung cancer cells can enter lymphatic vessels and begin to grow in lymph nodes around the bronchi and in the area between the two lungs. When lung cancer cells have reached the lymph nodes, they are more likely to have spread to other organs of the body as well. The extent of the cancer and decisions about treatment are based on whether or not the cancer has spread to the nearby lymph nodes.
Lung cancer is the most commonly diagnosed cancer. Detecting lung cancer in its early stages is difficult because it spreads quickly and many lesions are hard to see or reach. Traditionally, when doctors identify a suspicious lesion they perform a bronchoscopy, a needle biopsy or major surgery to remove a section of the lung. But as technology advances so are the tools available to help doctors diagnose and treat lung cancer.
Staging is the process of finding out how far a cancer has spread. Your treatment and outlook depend, to a large extent, on the cancer's stage. Also, staging is different for the two main types of lung cancers.
The system used to describe the growth and spread of non-small cell lung cancer (NSCLC) is based on three key pieces of information:
The TNM staging system is complex and can be difficult to understand. If you have any questions about the stage of your cancer, ask your doctor to explain it to you.
Depending on the stage of the disease and other factors, the main treatment options for people with non-small cell lung cancer (NSCLC) may include:
In many cases, more than one of these treatments may be used.
For small cell lung cancers, most doctors prefer the 2-stage system that divides these cancers into limited stage and extensive stage.
Roughly two out of three people with small cell lung cancer have extensive disease when their cancer is first found. Small cell lung cancer is often staged in this way because it helps separate patients who may benefit from more aggressive treatments, such as chemotherapy combined with radiation therapy, to try to cure the cancer from those for whom these treatments aren't likely to cure the cancer.
In choosing a treatment plan for small cell lung cancer, one of the most important factors is the stage of the cancer. Depending on the stage of the disease and other factors, the main treatment options for people with small cell lung cancer include:
If you have small cell lung cancer, you will probably get chemotherapy if you are healthy enough. If you have limited stage disease, radiation therapy and – rarely – surgery may be options as well.
