Written by Adam RowdenReviewed by Christina Chun, MPH
There are two main types of lung cancer: non-small cell lung cancer and small cell lung cancer.
According to the American Cancer Society, non-small cell lung cancer (NSCLC) makes up 80 to 85 percent of lung cancers in the United States. Small cell lung cancer (SCLC) makes up between 10 and 15 percent of lung cancers in the U.S.
NSCLC usually grows and spreads more slowly than SCLC.
There are several different types of NSCLC. These types are grouped together because the approach to treatment and outlook are usually similar.
The three most common types of NSCLC are as follows:
This is the most common type of NSCLC lung cancer. According to Lung Cancer Alliance, it represents about one third of lung cancer diagnosis. Adenocarcinoma develops from cells that make mucus in the airway lining.
Squamous cell cancer
Squamous cell lung cancer starts off in the thin, flat cells that line a person’s airways. Smoking often causes this type of lung cancer.
Large cell carcinoma
This type of lung cancer has cancerous cells that are large and rounded when looked at under a microscope. It is not that common, but does tend to grow quite quickly.
Here are the most common risk factors for NSCLC:
- Smoking tobacco: The main risk factor is smoking. Around80 percent of lung cancer deaths occur as a result of smoking. This includes cigarette smoke, pipe smoking, and cigar smoking.
- Secondhand smoke: Secondhand smoke is also a risk factor. Breathing in secondhand smoke can increase a person’s risk of developing lung cancer. In the U.S., secondhand smoke is believed to cause more than7,000 deaths from lung cancer each year.
- Exposure to dangerous substances: Other risk factors include exposure to harmful substances including radon, asbestos, and a variety of other cancer-causing substances.
- Radiation therapy to the chest: People who have hadradiation therapy to treat cancers in the chest are also more likely to develop NSCLC.
- Family history: Relatives of people who have had lung cancer may have a slightly increased risk of developing the disease themselves. This risk is increased if the relative was diagnosed at a younger age.
There are a number of symptoms of NSCLC. These include a persistent cough and regular shortness of breath.
Often symptoms will not appear for a long time, which makes it difficult to detect NSCLC.
Here is a list of other symptoms that can occur due to NSCLC:
- issues with breathing
- wheezing breath
- coughing up blood
- hoarse voice
- loss of appetite
- unknown weight loss
- pain or trouble swallowing
- swollen face
- swollen veins in the neck
Although these conditions can be symptoms of NSCLC, they are more likely to be caused by something else. However, if a person does experience these symptoms then they should visit a doctor straight away.
If NSCLC is left untreated then it may spread. This can cause other cancers to develop in other parts of the body. Here are some of the symptoms that a person may experience if NSCLC has spread to other parts of the body:
- pain in bones, such as in the back or hips
- issues with the nervous system includingheadaches, dizziness, and seizures
- yellowing skin (jaundice)
- lumps near the body’s surface
If a person does have symptoms of NSCLC, they should visit the doctor.
The doctor will look at the person’s medical history, ask about any risk factors, and do an examination. The doctor might look for signs of NSCLC using a combination of physical signs and an imaging scan.
If the results of the exam and associated risk factors point to a NSCLC, a number of tests will be carried out, such as a blood test.
Imaging tests and scans
Imaging tests involve the use X-rays, magnetic fields, and other methods to look inside a person’s body. Tests can look at specific areas to see if cancer is present. They can also see how far a cancer may have spread. Imaging tests can be used to see if treatment is working.
Imaging tests can also be used to see if there are signs that cancer may be coming back after treatment. These can include an X-ray of a person’s chest, CT scans, MRI scans, and others.
A doctor may also wish to carry out other tests to see if a person has lung cancer. These include:
- Sputum cytology: A doctor will take a sample of mucus that a person has coughed up from their lungs. They will then examine it under a microscope to see if it contains cancer cells.
- Thoracentesis: If there is a buildup of fluid around the lungs then a doctor may carry out this procedure. The doctor will use a needle to drain some of this fluid. The fluid will then be examined beneath a microscope to see if it contains cancer cells.
- Needle biopsy: This procedure involves using a hollow needle to get a small sample of tissue. This tissue is then examined for cancer cells.
- Bronchoscopy: A lighted and flexible fiber-optic tube is passed through the mouth or nose. Small instruments can then be passed down the tube and used to take biopsy samples. These samples are examined beneath a microscope to look for cancer cells.
There are a number of treatments for NSCLC, including:
- Surgery: Surgery may be required to cut out and remove any cancerous tissue.
- Chemotherapy: This treatment method uses medicines to shrink or kill the cancer.
- Radiation therapy: This involves using high-energy rays to kill the cancer.
- Targeted therapy: A doctor may wish to use specific drugs to block the growth and spread of the cancer.
The different stages of NSCLC allow a doctor to label how far the cancer has grown. The stages run from 1 to 4. The lower numbers indicate that the cancer has spread less. The stages are below:
- Stage 1: Found only in one lung and no lymph nodes.
- Stage 2: Spread to the lymph nodes surrounding the infected lung.
- Stage 3a: Spread to lymph nodes that sit around the windpipe, chest wall, and diaphragm, on the same side as the infected lung.
- Stage 3b: Spread to the lymph nodes on the other lung or in the neck.
- Stage 4: Spread throughout the rest of the body and other parts of the lungs.
The outlook for a person with NSCLC varies depending on a number of factors. These include how early the cancer was detected, how big the cancer has grown, if it has spread, and the person’s general health.