| || |
Diseases And Conditions
The Paget Foundation
Breast Cancer Metastatic to Bone: Questions & Answers About...
Breast Cancer Metastatic to Bone: Questions & Answers About...
The most common form of cancer among women, breast cancer can eventually migrate (metastasize) into bone through the bloodstream, thinning the bone and sometimes resulting in fractures. Article discusses early detection, prevention, treatment and outlook for patients."
National Institute of Health
The Paget Foundation
...about Breast Cancer Metastatic to Bone
In 1978, The Paget's Disease Foundation was founded as an organization devoted to helping patients with Paget's disease, a bone disease in which increased bone resorption is an important factor. Over the years, the foundation has expanded its programs to include other disorders of increased bone resorption. Since 1992, two such disorders, primary hyperparathyroidism and fibrous dysplasia, were added to the foundation's programs. In 1997, the name of the foundation was changed to The Paget Foundation for Paget's Disease of Bone and Related Disorders. With this booklet, The Paget Foundation is pleased to begin a program to help breast cancer patients whose tumors have spread to bone, a serious complication of breast cancer that also involves increased bone resorption. The goal of this publication is to provide accurate and uptodate information to patients and their physicians in order to help them deal more effectively with this major complication of breast cancer.
General Information About Breast Cancer in Bone
How common is breast cancer in the United States today and how is it diagnosed and initially treated?Once discovered, a small piece of the tumor is taken and examined under a microscope to determine if it is cancerous. The most common initial treatment is to then remove the tumor itself (lumpectomy) followed by radiation therapy to the breast or to remove the whole breast (mastectomy). Hormonal therapy, for example, tamoxifen (Nolvadex®), or chemotherapy are also given if the tumor is more than a half inch in size or the tumor has spread to the Iymph nodes under the arm.
More than 180,000 women are diagnosed with breast cancer each year, making it the most common cancer among women. Mammography is today's best method for detecting breast cancer early, when the chances for cure are greatest. Mammography is particularly valuable in that it can detect a tumor when it is quite small and before it can be felt in a self examination or by a physician as part of a physical examination. The earlier a tumor is discovered, the greater the cure rate. Regular mammography is strongly recommended for women over the age of 50, as it decreases the risk of dying from breast cancer by about one third. Larger tumors — those that are an inch or more in size — can be felt by the woman herself or by her doctor.
How often does the initially treated breast cancer return? Where does it go?
Although initial therapy is curative in more than half of women with breast cancer, the breast cancer may later reappear in the breast area or spread to other parts of the body (metastasize). Spread can occur soon after initial diagnosis and treatment or even 15 to 20 years later. Larger tumors or those which spread to lymph nodes are more likely to metastasize than those that are small and have not spread to nearby lymph nodes at the time of initial diagnosis. Of the group of women whose tumors spread to other regions of the body, more than half eventually develop bone metastases (the spread of the cancer to the bone). Spread to other organs (lungs, liver, or brain) is somewhat less common. Bone is a more common site of initial spread of breast cancer in older patients who have gone through menopause than in younger women.
What happens when breast cancer spreads to bone?
Spread of breast cancer to bone occurs after tumor cells from the original cancer break off and travel through the blood stream to bone. The tumor cells grow and multiply in the bone, eventually causing thinning of bone in the area where the cancer cells are deposited, bone pain, and, in some cases, a broken or fractured bone.
Back to Table of Contents
How is the spread of breast cancer to bone detected? Depending on the location of the breast cancer cells in bone and the x-ray appearance, additional tests may be necessary. For example, to evaluate the severity of the problem in a long bone (an arm or a leg), a CT scan may be ordered. If a bone in the spine (a vertebra) is involved, an MRI scan may be used. Bone scans are often done to evaluate the entire skeleton. Generally, bone scans and x-rays are performed only if a woman has symptoms They are not usually done for routine followup of breast cancer patients who have no skeletal complaints.
When a woman who has previously had breast cancer reports that she has new bone pain, her physician takes a careful history of symptoms and examines her. If the pain could be due to the spread of breast cancer to bone, x-rays of the painful areas are taken. If the bone has been thinned by tumor cells, the x-ray will show changes in bone that are called lytic metastases. After the damaged or thinned bone is treated to kill the tumor cells, the bone cells often fill in the thinned area to form a scar, called a blastic metastasis, which can also be seen on the x-ray of an affected bone. Rarely, a blastic metastasis can occur spontaneously.
A biopsy (removal of a small amount of tissue) of an abnormal area of bone seen on an x-ray may be performed to determine if breast cancer cells are present, especially if the other tests do not clearly establish the diagnosis.
In addition to x-rays, blood tests to measure calcium and alkaline phosphatase may be obtained.
Which parts of the skeleton are most likely to be involved with breast cancer and what types of problems can this cause for the patient? Fractures can occur when the hard surface of the bone is weakened by the growth of breast cancer cells. Weight-bearing bones such as those in the legs are more susceptible to such fractures. Pain in the knee, thigh, or groin when walking may be a symptom of spread of the breast cancer to the bones in these parts of the body and a possible warning that the affected bone could fracture with minimum stress, such as exercise. An arm bone weakened by breast cancer may break from the stress to the bone that occurs if the patient carries a heavy object. If the spine is an area of metastatic spread, a vertebra may fracture and collapse on itself, causing back pain. Breast cancer cells growing in a vertebra can also lead to pressure on the spinal cord or spinal nerves, resulting in weakness or loss of sensation in the arms and/or legs.
Breast cancer can spread to any part of the skeleton. Pain in a bone with or without evidence of a fracture is the most common symptom.
Less commonly, the spread of breast cancer to bone may release calcium into the blood, causing high blood calcium levels (hypercalcemia) and producing symptoms such as excessive thirst and urination, constipation, loss of appetite, excessive sleepiness, confusion, and, rarely, coma.
All of these problems require immediate medical attention. Effective treatments are available for pain, for prevention of fractures, and for hypercalcemia. Therefore, patients should not delay in reporting any of the above symptoms to their physician.
Treatment of Breast Cancer That Has Spread to Bone
Once the breast cancer has spread to bone, what treatments are given? If breast cancer cells are shown by bone scan and additional x-rays to have spread to several parts of the skeleton, radiation therapy to all of these locations may not be possible, since the total amount of radiation that can be given safely is limited. In this situation, hormonal therapy or chemotherapy might be started if not previously used or might be changed in some manner if the patient had been receiving such therapy before.
If x-rays of the skeleton reveal that the cancer has spread to bone in only one location, radiation therapy is given to that bone. This will typically eliminate the pain, prevent fractures, and may be the only treatment needed at that time.
Some patients are started on tamoxifen, a form of hormonal therapy. A temporary increase in bone pain (a "flare") or, more rarely, a short period of hypercalcemia occasionally develops in the first month of tamoxifen treatment in this setting and then improves with time. Pain flares or hypercalcemia associated with the starting of tamoxifen need to be evaluated by the patient's physician. For reasons we don't understand, they often predict a good response to tamoxifen over time.
Patients should also be provided with the pain medication that they require to relieve bone pain. If chemotherapy or hormone treatment are no longer effective in controlling bone pain, a radioactive substance called strontium 90 may be tried.
Recently, a bisphosphonate drug called pamidronate (Aredia®) has been approved by the FDA for the treatment of bone metastases from breast cancer. Given intravenously once a month, this medication appears to reduce the number of skeletal complications and to decrease the severity of the problems that can occur from breast cancer metastatic to bone.
What can be done if the tumor has weakened the bone so that a fracture is likely or has already occurred?
If an x-ray shows that a bone is thinned to the point that a fracture is likely, an orthopedic procedure may be necessary to support the bone and prevent fracture. For example, if the x-ray shows that the hip is at high risk of fracture, a hip replacement operation might be required. Preventing a fracture is easier and less painful than fixing a bone that has already broken. However, should a fracture of a bone weakened by breast cancer occur, orthopedic procedures can be promptly done to repair the fracture.
What can be done if the calcium released from the bone causes high blood levels of calcium?
The treatment of high blood calcium (hypercalcemia) usually involves the use of fluids containing sodium chloride given intravenously, often with the addition of other drugs by vein such as the bisphosphonate drugs, pamidronate or etidronate (Didronel®), or other drugs such as gallium nitrate (Ganite®) or plicamycin (Mithracin®). Sometimes salmon calcitonin, (Calcimar® and Miacalcin®), another drug which inhibits thinning of bone, is given intravenously or by injections under the skin. Steroid medicines such as prednisone or cortisone are sometimes used to treat hypercalcemia, but generally the bisphosphonate drugs mentioned above are the first choice of therapy.
What can be done to prevent the spread of breast cancer to bone? Ongoing research with several new bisphosphonate drugs and gallium nitrate is directed at prevention of the spread of breast cancer to bone.
The use of certain forms of chemotherapy or hormone therapy called "adjuvant" chemotherapy, beginning after the breast cancer is removed surgically, decreases the risk of breast cancer spreading to other organs including bone by 25-30 Radiation therapy given to the breast after a lumpectomy decreases the risk of a reappearance of breast cancer in the breast region, but does not decrease the risk of the cancer spreading to bone. The choice of which of these therapies should be used at the time of first treatment is based on the specific characteristics of each patient.
Back to Table of Contents
General Bone Health in Women With Breast Cancer
How important is calcium intake for women who have had breast cancer?
Women who have had breast cancer have the same nutritional needs for adequate calcium and vitamin D to maintain good bone health as do women without breast cancer. Current recommendations include taking between 1000 mg and 1500 mg of calcium daily after age 50. Note that four 8-ounce glasses of milk contain about 1200 mg of calcium. For women who do not consume many dairy products, calcium supplements in the form of tablets can be taken. A standard multivitamin generally contains 400 units of vitamin D, which is an appropriate daily intake.
If a woman who has had breast cancer is concerned about osteoporosis, can she take hormones such as estrogen?
The use of postmenopausal estrogen replacement therapy in women who have had previous breast cancers remains controversial. Most physicians prefer to avoid estrogen for such women. Tamoxifen, a drug frequently used to treat breast cancer, may also help prevent the loss of bone that leads to osteoporosis. Alendronate (Fosamax®), another bisphosphonate, and salmon calcitonin, drugs used for the treatment of osteoporosis in postmenopausal women, may be used safely in women who have had breast cancer.
Is exercise useful and safe in women with breast cancer?
Appropriate exercise is good for all women and should be undertaken under the direction of a physician to individualize the appropriate program to each patient's needs. For a woman with breast cancer that has spread to bone, certain types of weight-bearing exercise may cause pain or cause undue stress on weakened bone. If appropriate, exercise should be undertaken only after weight-bearing bones have been evaluated and treated.
Who Treats Patients With Breast Cancer in Bone?
What types of physicians and other health professionals treat patients with breast cancer affecting the skeleton? Orthopedic surgeons play a role if there is a risk of fracture or if a fracture has occurred. Neurologists and neurosurgeons may be part of the treatment team if a tumor involving the vertebrae in the spine is causing pressure on nerves. Physical medicine physicians may help in prescribing physical therapy. An endocrinologist may be called upon if hypercalcemia is a problem.
One or more of a group of healthcare professionals may be involved. Typically, the woman's oncologist (an internist who specializes in the medical treatment of cancer) together with her breast surgeon plan an initial approach to treatment, often with the help of a radiation oncologist, a specialist in radiation (x-ray) therapy for cancer.
Oncology and orthopedic nurses and physical therapists may also work with patients to assist with the use of medications and rehabilitation needed to return the patient to her regular daily activities.
To deal with the emotional and social impact of breast cancer that has spread to bone, the patient may want to consult a mental health professional (eg, psychologist, social worker, or psychiatrist). The use of psychotherapy and/or antidepressant medication may be helpful in some cases.
adjuvant therapy: Hormonal therapy or chemotherapy given at the time of initial diagnosis to decrease the risk of recurrence of breast cancer.
biopsy: A small piece of tissue from a tumor or suspected growth that is examined under a microscope to make a diagnosis.
bisphosphonates: Medications that inhibit or slow the thinning of bone.
bone scan: A test performed by a radiologist that allows the physician to check the entire skeleton for spread of cancer to bone.
chemotherapy: Drugs that kill cancer cells.
cortisone or prednisone: Steroid hormones sometimes used in the treatment of breast cancer.
CT and MRI scans: Special diagnostic procedures performed by a radiologist that allow a more detailed view of both bone and nearby muscles and other tissues.
hormonal therapy: Hormones that alter the environment of cancer cells in ways that stop them from continuing to grow.
metastases: Cancer cells growing in areas of the body a distance away from the original cancer location.
lytic metastases: The thinned areas of bone that occur when cancer cells spread into and grow within bone tissue.
blastic metastases: The thicker than normal bone that may occur spontaneously or with healing of a lytic bone metastasis.
osteoporosis: A generalized loss of and thinning of bone that occurs in women after menopause and increases the risk of fractures, especially in the spine, wrist, and hip.
radiation therapy: Use of radiation to a small region of the body to kill cancer cells.
salmon calcitonin: A medication that inhibits or slows the thinning of bone.
tamoxifen: A medication that works by interfering with the stimulation of certain types of breast cancer cells by estrogen.
tumor: An abnormal mass of tissue. Tumors are either benign (noncancerous) or malignant (cancerous).
For more information or additional resources, patients and families can contact their local chapter of the American Cancer Society, at 1-800-ACS-2345 (1-800-227-2345) or The National Cancer Institute at 1-800-4-CANCER (1-800-422-6237)
This publication was written by:
Karen Antman, MD, Professor of Medicine, Columbia University College of Physicians and Surgeons Director
Columbia Presbyterian Comprehensive Cancer Center,
New York, NY
Ethel S. Siris, MD, Professor of Clinical Medicine, Columbia University College of Physicians and Surgeons, New York, NY
Vice-Chair, Board of Directors, The Paget Foundation
Editorial assistance was also provided by:
Frederick R. Singer, MD Director
Endocrine/Bone Disease Program, John Wayne Cancer Institute at St. John s Hospital and Health Center, Santa Monica, CA
Chair, Board of Directors, The Paget Foundation
This brochure was developed in partnership with: Osteoporosis and Related Bone Diseases-National Resource Center
1150 17th Street, NW
Washington, DC 20036-4603
Tel: (202) 223-0344
Fax: (202) 223-2237
TTY: (202) 466-4315
The National Resource Center is operated by the National Osteoporosis Foundation in collaboration with The Paget Foundation and the Osteogenesis Imperfecta Foundation, and supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health.
This publication was developed in collaboration with the U.S. Public Health Service's Office on Women's Health within the Department of Health and Human Services.
©Copyright, The Paget Foundation, 1996
Back to Top
Back to Paget Foundation
Last updated April 03, 1997