Lung cancer is cancer that starts in the cells that make up the lungs. It isn’t cancer that spreads to the lungs from other parts of the body. This is key because treatment is based on the original site of the tumor. For example: If a tumor begins in the breast and spreads to the lungs, it would be treated as metastatic breast cancer—not lung cancer.
Lungs are sponge-like organs in your chest. Their job is to bring oxygen into the body and to get rid of carbon dioxide. When you breathe air in, it goes into your lungs through your windpipe. The trachea divides into tubes called bronchi, which enter the lungs. These split into smaller branches called bronchioles. At the end of the bronchioles are tiny air sacs called alveoli. The alveoli move oxygen from the air into your blood. They take carbon dioxide out of the blood. This leaves your body when you breathe out.
About 250,000 new cases of lung cancer are diagnosed each year. The average age of those who receive a diagnosis is 70.
There are two types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Understanding the differences between these types may lessen anxiety about your diagnosis and treatment.
Non-small cell lung cancer: NSCLC accounts for 85% to 90% of lung cancer cases. Each subtype is named for the type of cell it develops in. There are three subtypes.
Small cell lung cancer: Only about one in 10 to three in 20 people diagnosed with lung cancer have small-cell lung cancer. It's also almost exclusively found in smokers. It tends to grow more quickly than NSCLC. It often spreads to other parts of the body at an earlier stage.
Lung cancer often doesn't cause symptoms in its early stages. This is when it's small and hasn't spread. In fact, many lung cancers don't cause symptoms until they've already spread.
When lung cancer does cause symptoms, they’re often like those you might have anyway if you smoke. For example, some early symptoms of lung cancer include shortness of breath and coughing.
These are some of the more common symptoms of lung cancer:
Some symptoms can be caused by lung cancer spreading to other parts of the body:
What causes lung cancer can be varied. But there are risk factors that increase the likelihood of developing lung cancer. Some risk factors can be controlled and some cannot.
Smoking tobacco is the leading risk factor for lung cancer. The longer you smoke, and the more you smoke each day, the higher your risk. Cigarettes are the main cause, but cigar and pipe smoking are almost as likely to cause the disease. Smoking is linked to about eight in 10 lung cancer deaths.
For people who smoke, this information might seem overwhelming. Yet, it’s important to know you’re in control of this risk factor. Quitting smoking, even after many years, can substantially lower your risk for lung cancer.
You can get cancer without smoking. Secondhand smoke is another leading cause of lung cancer. Quitting smoking will lower your risk for lung cancer and lowers the risk of your loved ones developing cancer, as well.
One of the most important ways to prevent getting lung cancer is to not smoke or to quit smoking.
Other ways to help prevent cancer include:
Studies have shown that low-dose CT (LDCT) scans can help detect lung cancer early in certain high-risk people. This specifically includes heavy smokers ages 50 to 77. Heavy smokers are defined as smoking at least one pack a day for over 20 years.
LDCT scans use X-rays to create detailed 3-D images of your lungs. The scans are painless and require no special preparation. You will lie down on a narrow table as your body passes through a ring-shaped CT scanner. You may be asked to hold your breath a few times during the test.
LDCT scans can spot abnormal areas that regular chest X-rays might miss. The benefit is significant: a lower risk of dying from lung cancer.
Keep in mind, LDCT scans do not find all lung cancers. It’s also possible the cancers they do find may have already progressed to a later stage.
If your health care provider thinks you may have lung cancer, you will need certain exams and tests to be sure. You might need to:
Any of these tests might suggest that you have lung cancer. If imaging tests show something that doesn't look normal, such as a mass or fluid, you'll need to have a biopsy. This is when a health care provider takes out a tiny sample of the mass or some of the fluid for testing at a lab. A biopsy is almost always needed to diagnose lung cancer.
A lung biopsy can be done in many ways:
If the biopsy confirms lung cancer, your providers likely will order more tests. The test results will help determine if the cancer has spread beyond the lungs and what treatment options are best for you.
When staging lung cancer, the following three factors are considered:
Both non-small cell and small cell lung cancers are then put into stage groupings based on this information. These groupings give an overall description of the cancer. A stage grouping can have a value of 0 to 4. The higher the number, the more advanced the cancer is.
Lung cancer staging is complex. Be sure to ask your healthcare provider to explain the stage of your cancer to you in a way you can understand.
Several types of treatment can be used for lung cancer. Different combinations of treatment may be used, depending on the type and stage (extent) of the cancer, and other factors. Each treatment has its own goals. Here is an overview of each type of treatment:
According to the American Cancer Society, the five-year survival rate is based on whether the cancer has spread.
The five-year survival rate for non-small cell lung cancer is about 65% if it has remained in the area of origin, known as localized. The five-year survival rate is 37% when the cancer has spread to areas nearby, like the lymph nodes. The five-year survival rate is 9% when the cancer has spread to distant areas in the body.
The five-year survival rate for small cell lung cancer is 30% when it’s localized, 18% when it has spread to other areas surrounding the lungs and 3% when it has spread to distant areas in the body.