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.

Smoking causes most cases of lung cancer. 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 lung cancer.

High levels of air pollution, working with or near cancer-causing chemicals or materials (such as asbestos), 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.

Early lung cancer may not cause any symptoms. Symptoms you should watch for include:

• Cough that doesn't go away
• Coughing up blood
• Shortness of breath
• Wheezing
• Chest pain
• Loss of appetite
• Losing weight without trying
• Fatigue

Other symptoms that may be due to NSCLC:

• Weakness
• Swallowing difficulty
• Nail problems
• Joint pain
• Hoarseness or changing voice
• Swelling of the face
• Facial paralysis
• Eyelid drooping
• Bone pain or tenderness

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 include:

• Chest x-ray
• CBC
• Sputum test
• Bone scan
• CT scan
• MRI
• Positron emission tomography (PET) scan
• Thoracentesis

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:

• Bronchoscopy combined with biopsy
• Pleural biopsy
• CT scan directed needle biopsy
• Mediastinoscopy with biopsy
• Open lung biopsy
• Endoscopic esophageal ultrasound (EUS) with biopsy

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

There are many different types of treatment for non-small cell lung cancer:

• Surgery - part or all of the lung is removed
• Radiation therapy - uses powerful x-rays or other radiation to kill cancer cells
• Chemotherapy - uses drugs to kill cancer cells and stop new ones from growing
• 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
• Watchful waiting - in rare cases, the person may only be monitored until symptoms change

Treatment depends upon the stage of the cancer. A combination of treatments may be needed. Research has suggested that chemotherapy or a combination of chemotherapy and radiation therapy prior to surgery might be the best treatment for some patients.

Surgery is the often the first line of treatment for most patients with stage I and II non-small cell lung cancer, and some patients with stage III tumors. Surgery can cure the disease.

Chemotherapy alone is often used when the cancer has spread (stage IV). Chemotherapy has been shown to prolong the life and improve the quality of life in some stage IV patients.

For additional information and resources, see cancer support group.

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

If you smoke, stop smoking. It's never too early to quit. 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 would not find help improve a person’s chance for a cure.

Mehra R, Moore BA, Crothers K, Tetrault J, Fiellin DA. The association between marijuana smoking and lung cancer: a systematic review. Arch Intern Med. 2006 Jul 10;166(13):1359-67.

American Cancer Society. Cancer Facts and Figures 2006. Atlanta, Ga: American Cancer Society; 2006.

U.S. Preventive Services Task Force. Lung cancer screening. Ann Int Med. 2004;140:738-739.

Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKena WG. Clinical Oncology. 3rd ed. Orlando, Fl: Churchill Livingstone; 2004:1690-1701.