Lung cancer - non-small cell

 

Alternative Names

Cancer - lung - non-small cell; Non-small cell lung cancer; NSCLC; Adenocarcinoma - lung; Squamous cell carcinoma - lung

Definition

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 common types 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 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

Smoking causes most cases (around 90%) of lung cancer. The risk depends on the number of cigarettes you smoke each 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 do 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:

  • Asbestos
  • 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

Symptoms

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

Other symptoms that may be due to NSCLC, often in the late stages:

These symptoms can be due to other, less serious conditions. It is important to talk to your health care provider if you have symptoms.

Exams 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 you smoke 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 done to diagnose lung cancer or see if it has spread include:

In most cases, a piece of tissue is removed from your lungs for examination under a microscope. This is called a biopsy. There are several ways to do this:

If the biopsy shows cancer, more imaging tests are done to find out the stage of the cancer. Stage means how big the tumor is and how far it has spread. NSCLC 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 has not 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 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

Treatment

There are many different types of treatment for NSCLC. Treatment depends on the stage of the cancer.

Surgery is the common treatment for NSCLC 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 cells from growing. Treatment may be done in the following ways:

  • Chemotherapy alone is often used when the cancer has spread outside the lung (stage IV).
  • It may also be given before surgery or radiation to make those treatments more effective. This is called neoadjuvant therapy.
  • It may be given after surgery to kill any remaining cancer. This is called adjuvant therapy.

Controlling symptoms and preventing complications during and after chemotherapy is an important part of care.

Radiation therapy can be used with chemotherapy if surgery is not possible. Radiation therapy uses powerful x-rays or other forms of radiation to kill cancer cells. Radiation may be used to:

  • Treat the cancer, along with chemotherapy, if surgery is not possible
  • Help relieve symptoms caused by the cancer, such as breathing problems and swelling
  • Help relieve cancer pain when the cancer has spread to the bones

Controlling symptoms during and after radiation to the chest is an important part of care.

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

Support Groups

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 (Prognosis)

The 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 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 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.

When to Contact a Medical Professional

Call your health care provider if you have symptoms of lung cancer, particularly if you smoke.

Prevention

If you smoke, now is the time to quit. If you are having trouble quitting, talk with your doctor. There are many methods to help you quit, from support groups to prescription medicines. Also, try to avoid secondhand smoke.

If you smoke or used to smoke, talk with your doctor about getting screened for lung cancer. To get screened, you need to have a CT scan of the chest. 

References

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 Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Non-small cell lung cancer. Version 4.2014. Available at http://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf. Accessed August 31, 2014.

National Cancer Institute: PDQ Non-Small Cell Lung Cancer Treatment. Bethesda, MD: National Cancer Institute. Date last modified 06/30/2013. Available at: http://cancer.gov/cancertopics/pdq/treatment/non-small-cell-lung/Patient. Accessed August 31, 2014.

Review Date: 8/31/2014
Reviewed By: Yi-Bin Chen, MD. Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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