Normal calcium regulation
Kidney function

Hypercalcemia occurs in 10%-20% of people with cancer, although it occurs much less often in children. The cancers most often associated with hypercalcemia are cancer of the breast and lung, as well as certain cancers of the blood, particularly multiple myeloma. Early diagnosis and treatment with fluids and drugs that lower calcium levels in the blood can improve symptoms in a few days, but diagnosis may be difficult. Symptoms of hypercalcemia can appear gradually and may resemble symptoms of many cancers and other diseases. Early diagnosis and treatment are not only lifesaving in the short term, but may also increase the patient's ability to complete cancer therapy and improve the patient's quality of life.

Patients who have advanced terminal cancer and are no longer receiving treatment for the cancer may choose not to be treated for hypercalcemia. This option should be considered by a patient and his or her family in advance, before symptoms of hypercalcemia occur.

Healthy people consume about the same amount of calcium in their diet as their bodies lose in urine, feces, and sweat. Hypercalcemia associated with cancer disrupts the body's ability to maintain a normal level of calcium.

Normal, healthy kidneys are able to filter large amounts of calcium from the blood, excrete the excess not needed by the body, and retain the amount of calcium the body does need. However, hypercalcemia may cause such high levels of calcium in the body that the kidneys are overworked and become unable to excrete the excess. Some tumors produce a substance that can cause the kidneys to excrete too little calcium. This results in a large amount of urine being produced, which then causes dehydration. Dehydration may lead to appetite loss, nausea, and vomiting which make the dehydration worse. Inactivity caused by weakness and tiredness may increase the amount of calcium in the blood by increasing the amount of calcium that is absorbed from the bones. Calcium deposits may collect in the kidneys, causing permanent damage.

Glossary Terms

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

A mineral found in teeth, bones, and other body tissues.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

A condition caused by the loss of too much water from the body. Severe diarrhea or vomiting can cause dehydration.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The things a person eats and drinks.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

Liquid.

Higher than normal levels of calcium in the blood. Some types of cancer increase the risk of hypercalcemia.

One of a pair of organs in the abdomen. Kidneys remove waste from the blood (as urine), produce erythropoietin (a substance that stimulates red blood cell production), and play a role in blood pressure regulation.

One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.

A type of cancer that begins in plasma cells (white blood cells that produce antibodies). Also called Kahler disease, myelomatosis, and plasma cell myeloma.

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Disease that cannot be cured and will cause death.

Treatment.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.

To eject some or all of the contents of the stomach through the mouth.