Stage IV breast cancer, also known as metastatic breast cancer, is the most serious form of the disease. In this stage, the cancer has spread to other parts of the body; for breast cancer, the most common sites of metastases are the liver, lungs, brain and bone, according to the Network of Strength. When breast cancer has spread to the bones, certain medications may be used to maintain bone strength, including zoledronate.
Significance
In 2010 in the United States, it is estimated that more than 207,000 women and almost 2,000 men will be diagnosed with breast cancer, according to the National Cancer Institute. That same year, nearly 40,000 women and 400 men will die from the disease. Ten percent of new breast cancer diagnoses involve metastatic disease, where the cancer has spread to distant organs of the body, says imaginis.com.
Treatment
Treatment for breast cancer depends on the size of the tumor, stage of the cancer, and the health and preferences of the patient. Typically, more than one treatment modality is used, and can include surgery, radiation, chemotherapy, hormone therapies, targeted therapies, high-dose chemotherapy with stem cell transplant and bisphosphonates. Bisphosphonates are not used to attack cancer cells, but help to strengthen and reduce the risk of fractures in individuals with bone metastases, according to the American Cancer Society. They are often used in conjunction with other treatments, such as chemotherapy or radiation. One of these bisphosphonates is zoledronate, often called zoledronic acid, with the brand name Zometa.
Function
Breast cancer that spreads to the bones causes the bone to break down, leading to weakening of the bones, bone pain and fractures. When bone breaks down, excess calcium is released into the bloodstream, causing high blood calcium levels, which can be dangerous. Zoledronic acid helps to stop the breakdown of bone from cancer and slows down tumor growth in the bones, according to the American Cancer Society. It also helps to reduce calcium blood levels by slowing down the release of calcium into the bloodstream, says the American Cancer Society.
Effects
Zoledronate can cause side effects, but these can vary among individuals. Rxlist.com lists several side effects, including fever, nausea, constipation, diarrhea, stomach pain, vomiting and loss of appetite. Some individuals may also experience symptoms similar to the flu, such as fever, chills and body aches. Osteonecrosis of the jaw, also termed ONJ, is a potential side effect of zoledronic acid and similar bisphosphonates, says rxlist.com. This involves damage and degradation of the jawbone, especially when these medications are taken after dental work, and can be serious.
Warning
Talking to the prescribing health-care professional about any medications or supplements an individual is taking can help to prevent adverse interactions and serious complications from this drug. During treatment with zoledronic acid, blood tests are typically given to monitor kidney function and avoid any problems. Women who are pregnant or want to get pregnant soon after treatment should not take zoledronic acid, says the American Cancer Society, as it can remain in the blood for years and may harm a fetus.
References
- National Cancer Institute: Breast cancer home page
- Imaginis: Advanced (Metastatic) breast cancer
- American Cancer Society: Breast cancer: Bisphosphonates
- American Cancer Society: Cancer Drug Guide: Zoledronic acid
- Rxlist: Zometa: Side effects and interactions
- Network of Strength: Recurrent and advanced breast cancer
