Adenocarcinomas are often found in an outer area of the lung.
Squamous cell carcinomas are usually found in the center of the lung next to 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.
Causes, incidence, and risk factors
Smoking causes most cases of lung cancer. The risk depends on the number of cigarettes you smoke every day and for how long you have smoked. Being around the smoke from other people (secondhand smoke) also raises your risk of lung cancer. But some people who do not smoke and have never smoked develop lung cancer.
Research shows that smoking marijuana may help cancer cells grow. But there is no direct link between smoking marijuana and developing lung cancer.
Constant exposure to high levels of air pollution and drinking water that has a high level of arsenic can increase your risk of lung cancer. A history of radiation therapy to the lungs can also increase risk.
Working with or near cancer-causing chemicals or materials can also increase risk. Such chemicals include:
Chemicals such as uranium, beryllium, vinyl chloride, nickel chromates, coal products, mustard gas, chloromethyl ethers, gasoline, and diesel exhaust
Certain alloys, paints, pigments, and preservatives
Products using chloride and formaldehyde
Early lung cancer may not cause any symptoms. Symptoms you should watch for include:
These symptoms can be due to other, less serious conditions. It is important to talk to your health care provider.
Signs and tests
The doctor will perform a physical exam and ask about your medical history. You will be asked if you smoke, and if so, how much and for how long. You will also be asked about other things that may have put you at risk of lung cancer, such as exposure to certain chemicals.
When listening to the chest with a stethoscope, the doctor may hear fluid around the lungs.
This may suggest cancer.Tests that may be performed to diagnose lung cancer or see if it has spread include:
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
You can ease the stress of illness by joining a cancer support group. Sharing with others who have common experiences and problems can help you not feel alone.
Outlook varies. Most often, NSCLC grows slowly. In some cases, it can be very aggressive 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.
Cure rates are related to the stage of disease and whether you are able to have surgery.
Stages I and II cancers have the highest survival and cure rates.
Stage III cancer can be cured in some cases.
Stage IV cancer that has returned is almost never cured. The goals of therapy are to extend and improve quality of life.
Calling your health care provider
Call your health care provider if you have symptoms of lung cancer, particularly if you smoke.
If you smoke, now is the time to quit. Also, try to avoid secondhand smoke,.
Johnson DH, Blot WJ, Carbone DP, et al. Cancer of the lung: non-small cell lung cancer and small cell lung cancer. In: Abeloff MD, Armitage JO, Niederhuber JE, et al., eds. Abeloff’s Clinical Oncology. 4th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 76.
National Cancer Institute: PDQ Non-Small Cell Lung Cancer Treatment. Bethesda, MD: National Cancer Institute. Date last modified 08/08/2013. Available at:http://cancer.gov/cancertopics/pdq/treatment/non-small-cell-lung/Patient. Accessed September 24, 2013.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Non-small cell lung cancer. Version 2.2013. Available at http://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf. Accessed September 24, 2013.
Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.