Hypercalcemia in Cancer Patients

Hypercalcemia—that is, an elevated calcium level in the blood—is a common and serious complication, affecting 10 to 15 percent of people with advanced cancer. It is diagnosed by a simple blood test and is checked frequently in people living with cancer.

An elevated calcium level is most common in people with lung cancer or breast cancer but may occur with any type of cancer, especially cancers like lymphomas and multiple myeloma.

An awareness of the symptoms of elevated calcium may help you contact your doctor before it becomes a serious problem. Many of the symptoms are vague and can be present with conditions other than hypercalcemia, especially some cancer treatments, so it's important to be aware of them. Some of these include:

• Nausea
• Vomiting
• Loss of appetite
• Abdominal pain
• Increased thirst
• Decreased urination
• Weakness
• Constipation
• Muscle and joint pain
• Kidney stones
• Confusion, hallucinations, or personality changes
• Irregular heart rate
• When severe, coma and death

There are several causes of a high calcium level in people with cancer. Some of these include:

• Release of calcium from cancer growing in bones (such as multiple myeloma) or spread of cancer to bones
• Secretion of hormone-like substances by cancer cells that increase the calcium level (in paraneoplastic syndrome for example.) These substances act like parathyroid hormone (a hormone secreted by the parathyroid glands which sit behind the thyroid gland) and stimulate the release of calcium from the bones 
• Kidney dysfunction in which the kidneys do not remove calcium from the blood as they are meant to do
• Dehydration

The treatment of hypercalcemia will vary depending upon how elevated your calcium is, as well as the cause. In addition to treating the tumor (which may decrease the level) other treatments include:

• IV fluids
• Steroids
• Medications to lower the calcium level such as bisphosphonates. Calcitonin, gallium nitrate, or mithramycin may sometimes be used. New therapies are being studied (such as denosumab) that appear promising for treatment in the future
• Dialysis if hypercalcemia is very severe

Hypercalcemia can be a very serious complication of cancer (especially advanced cancer) but can be very treatable when caught early. In general, hypercalcemia is associated with a poorer prognosis overall for someone living with cancer, and specifically, has been found to be associated with a shorter life expectancy in people with lung cancer.

Preventing hypercalcemia is the best treatment, and there are a few things you can do to help maintain a normal calcium level. Some of these include:

• Stay well hydrated, and call your doctor if you are nauseous and unable to keep fluids down.
• Engage in regular physical activity.
• Get enough salt in your diet.

While staying well hydrated can help, decreasing the amount of calcium in foods you eat, such as avoiding dairy products, doesn't help prevent an elevated calcium level.

Caring for Yourself

Hypercalcemia is but one of the complications that may occur with cancer. Taking a moment to learn about the warning signs ahead of time can sometimes less anxiety when you are actually faced with these symptoms. Check out some of the common emergencies which can occur with cancer, and when to call 911.