Metastasis is the spread of cancer to other body parts (Fig. 38-3). Cancer cells break off the tumor and travel to other body parts. New tumors grow in other body parts. This occurs if cancer is not treated and controlled.

Fig. 38-3 A, Tumor in the lung. B, Tumor has metastasized to the other lung. (Modified from Belcher AE: *Cancer nursing,* St Louis, 1992, Mosby.)

Cancer can occur almost anywhere. Common sites are the skin, lung and bronchus, colon and rectum, breast, prostate, uterus, ovary, urinary bladder, kidney, mouth and pharynx, pancreas, and thyroid gland. Cancer is the second leading cause of death in the United States.

Risk factors

Certain factors increase the risk of cancer. The National Cancer Institute describes these risk factors:

• Growing older. Cancer occurs in all age-groups. However, most cancers occur in persons over 65 years of age.

• Tobacco. This includes using tobacco (smoking, snuff, and chewing tobacco) and being around tobacco (second-hand smoke). This risk can be avoided.

• Sunlight. Sun, sunlamps, and tanning booths cause early aging of the skin and skin damage. These can lead to skin cancer. Limit time in the sun. Avoid sunlamps and tanning booths.

• Ionizing radiation. This can cause cell damage that leads to cancer. Sources are x-rays and radon gas that forms in the soil and some rocks. Miners are at risk for radon exposure. Radon is found in some homes. Radioactive fallout is another source. It can come from nuclear power plant accidents and from the production, testing, or use of atomic weapons.

• Certain chemicals and other substances. Painters, construction workers, and those in the chemical industry are at risk. Household substances also carry risks—paint, pesticides, used engine oil, and other chemicals.

• Some viruses and bacteria. Certain viruses increase the risk of these cancers—cervical, liver, lymphoma, leukemia, Kaposi’s sarcoma (a cancer associated with AIDS, p. 598), stomach.

• Certain hormones. Hormone replacement therapy for menopause may increase the risk of breast cancer. Some pregnant women received diethylstilbestrol (DES), a form of estrogen, between the early 1940s and 1971. They are at risk for breast cancer. Their daughters are at risk for a certain type of cervical cancer.

• Family history of cancer. Certain cancers tend to occur in families. They include melanoma and cancers of the breast, ovary, prostate, and colon.

• Alcohol. More than 2 drinks a day increases the risk of certain cancers. Such cancers are of the mouth, throat, esophagus, larynx, liver, and breast. Women should have only 1 drink a day. Men should have only 2 drinks a day.

• Poor diet, lack of physical activity, and being over-weight. A high-fat diet increases the risk of cancers of the colon, uterus, and prostate. Lack of physical activity and being over-weight increase the risk for cancers of the breast, colon, esophagus, kidney, and uterus.

Treatment

If detected early, cancer can be treated and controlled (Box 38-1). Treatment depends on the tumor type, its site and size, and if it has spread. The treatment goal may be to:

• Cure the cancer

• Control the disease

• Reduce symptoms for as long as possible

Box 38-1

Some Signs and Symptoms of Cancer

• Thickening or lump in the breast or any other part of the body

• New mole or an obvious change in an existing mole

• A sore that does not heal

• Hoarseness or cough that does not go away

• Changes in bowel or bladder habits

• Discomfort after eating

• A hard time swallowing

• Weight gain or loss with no known reason

• Unusual bleeding or discharge

• Feeling weak or very tired

From National Cancer Institute: What you need to know about™ cancer, NIH Publication No. 06-1566, Bethesda, Md, August 2006.

Some cancers respond to one type of treatment. Others respond best to two or more types. Cancer treatments also damage healthy cells and tissues. Side effects depend on the type and extent of the treatment.

Surgery

Surgery removes tumors. It is done to cure or control cancer or to relieve pain from advanced cancer.

Post-operative pain is controlled with pain-relief drugs. The person may feel weak or tired for a while.

Radiation therapy

Radiation therapy (radiotherapy) kills cells. X-ray beams are aimed at the tumor. Sometimes radioactive material is implanted in or near the tumor.

Cancer cells and normal cells receive radiation. Both are destroyed. Radiation therapy:

• Destroys certain tumors

• Shrinks a tumor before surgery

• Destroys cancer cells that remain after surgery

• Controls tumor growth to prevent or relieve pain

Burns, skin breakdown, and hair loss can occur at the treatment site. The doctor may order special skin care measures. Extra rest is needed for fatigue. Discomfort, nausea, vomiting, diarrhea, and loss of appetite (anorexia) are other side effects.