Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. It usually grows and spreads more slowly than small cell lung cancer.
There are three forms of NSCLC:
- Adenocarcinomas are often found in an outer area of the lung.
- Squamous cell carcinomas are usually found in the center of the lung by an air tube (bronchus).
- Large cell carcinomas can occur in any part of the lung. They tend to grow and spread faster than the other two types.
Cancer - lung - non-small cell; Non-small cell lung cancer; NSCLC; Adenocarcinoma - lung; Squamous cell carcinoma - lung
Smoking causes most cases of lung cancer. The risk depends upon the number of cigarettes smoked every day and for how long someone has smoked. Being around the smoke from others (secondhand smoke) also raises your risk for lung cancer. However, people who do not smoke and have never smoked have become sick with lung cancer.
A review of decades of research has recently shown that smoking marijuana may help cancer cells grow, but there is no direct link between the drug and developing lung cancer.
High levels of air pollution and drinking water containing high levels of arsenic can increase your risk for lung cancer. Radiation therapy to the lungs can also increase the risk.
Working with or near the following cancer-causing chemicals or materials can also increase your risk:
- Products using chloride and formaldehyde
- Certain alloys, paints, pigments, and preservatives
Early lung cancer may not cause any symptoms. Symptoms you should watch for include:
Other symptoms that may be due to NSCLC:
Note: These symptoms can be due to other, less serious conditions. It is important to talk to your health care provider.
The health care provider will perform a physical exam and ask questions about your medical history. You will be asked if you smoke, and if so, how long you have smoked.
When listening to the chest with a stethoscope, the health care provider can sometimes hear fluid around the lungs, which could (but doesn't always) suggest cancer.
Tests that may be performed to diagnose lung cancer or see if it has spread include:
- Chest x-ray
Sputum test to look for cancer cells
- Bone scan
- CT scan of the chest
- MRI of the chest
- Positron emission tomography (PET) scan
In some cases, the health care provider may need to remove a piece of tissue from your lungs for examination under a microscope. This is called a biopsy. There are several ways to do this:
If the biopsy reveals you do have lung cancer, more imaging tests will be done to determine the stage of the cancer. Stage means how big the tumor is and how far it's spread. Non-small cell lung cancer is divided into five stages:
- Stage 0 - the cancer has not spread beyond the inner lining of the lung
- Stage I - the cancer is small and hasn't spread to the lymph nodes
- Stage II - the cancer has spread to some lymph nodes near the original tumor
- Stage III - the cancer has spread to nearby tissue or spread to far away lymph nodes
- Stage IV - the cancer has spread to other organs of the body such as the other lung, brain, or liver
For additional information and resources, see cancer support group.
The outlook varies widely. Most often, NSCLC develops slowly and causes few or no symptoms until very late stages. However, in some cases, it can be extremely agressive and cause rapid death. The cancer may spread to other parts of the body, including the bone, liver, small intestine, and brain.
Chemotherapy has been shown to prolong the life and improve the quality of life in some patients with stage IV NSCLC.
Cure rates are related to the stage of disease and whether you are able to have surgery.
- Stage I and II cancer can be cured with surgery, sometimes in more than 50% of cases.
- Stage III tumors can be cured in some cases, but cure rates are much lower than earlier stage NSCLC
- Patients with stage IV disease are almost never cured, and the goals of therapy are to extend and improve the quality of their life.
- Spread of disease beyond the lung
- Side effects of surgery, chemotherapy, or radiation therapy
There are many different types of treatment for non-small cell lung cancer. Treatment depends upon the stage of the cancer.
Surgery is the often the first line of treatment for patients with non-small cell lung cancer that has not spread beyond nearby lymph nodes. The surgeon may remove:
- One of the lobes of the lung (lobectomy)
- Only a small part of the lung (wedge or segment removal)
- The entire lung (pneumonectomy)
Some patients need chemotherapy. Chemotherapy uses drugs to kill cancer cells and stop new ones from growing.
- Chemotherapy alone is often used when the cancer has spread (stage IV).
- It may also be given before surgery or radiation to make those treatments more effective.
- It may be given after surgery (called adjuvant therapy) to kill any remaining microscopic areas of cancer.
Radiation therapy uses powerful x-rays or other forms of radiation to kill cancer cells. Radiation therapy can be used with chemotherapy if surgery is not possible.
The following treatments are mostly used to relieve symptoms caused by NSCLC:
- Laser therapy - a small beam of light burns and kills cancer cells
- Photodynamic therapy - uses a light to activate a drug in the body, which kills cancer cells
If you smoke, stop smoking. It's never too early to quit. People who have smoked in the past can be at increased risk for lung cancer more than 20 years after quitting, although the risk drops significantly in the first year after quitting. There are benefits to quitting smoking, even for people who are well into middle age.
Try to avoid secondhand smoke.
Eat a diet rich in fruits and vegetables.
Routine screening for lung cancer is not recommended. Many studies have been done to look at the idea, but scientists have concluded that, at this time, screening does not help improve a person’s chance for a cure.
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