Like any other drug or therapy, breast cancer treatment also has its own side effects. One of the side effects of breast cancer treatment is rapid bone loss leading to osteoporosis. The following are treatments for breast cancer that can significantly cause bone loss:
- Chemotherapy: This therapy has a direct impact on the health of the bones. It is observed that women who are nearing menopause and are undergoing chemo treatment may show a significant amount of bone loss since chemotherapy can cause an early menopause. If this therapy pushes the body for an early menopause, then bone loss can start while one is on treatment and will continue to do so even after treatment.
- Aromatase Inhibitors: This is a type of hormonal therapy that works by preventing the formation of estrogen in the body. Less production of estrogen can result in bone loss while the treatment is ongoing. This treatment is also mostly used in women undergoing postmenopausal stage and diagnosed with hormone receptor-positive breast cancer.
- Ovarian Shutdown: Refers to a method of removal of ovaries with the help of medications. The removal of the ovaries causes an irreversible menopause, wherein the bone density tends to drop all of a sudden after the ovaries are removed. This method temporarily stops the ovaries to produce estrogen.
Treatment and Common Brands
Three types of drugs are suggested to reduce the risk of decline in bone density during the course of treatment, and they are:
- Bisphosphonates (zoledronic acid, risedronate, alendronate sodium, and ibandronate)
- Evista (raloxifene)
- Targeted therapies such as Xgeva and Prolia (denosumab)
Denosumab (Xgeva, Prolia)
Denosumab is usually given to patients with breast cancer and bone metastasis. The drug is also used to treat patients who have a giant cell tumor present in the bone, which can be removed with the help of surgery. Apart from these medical problems, denosumab is used for cancer patients who have high levels of calcium in the blood.
Denosumab is also a RANKL (receptor activator of nuclear factor kappa-B ligand) inhibitor. The drug works by slowing down the loss of bone mass, and in turn, increasing the strength of the bone. Thus, it would lead to a reduction in the risk of any bone-related medical problems in patients with bone metastasis (cancer that has spread to the bones).
Precautions Before Taking Denosumab
Do not take denosumab if you are allergic to any of the ingredients present in the medicine, if you have low levels of calcium in the body, and if you are taking other medications that have some traces of denosumab.
There are certain medications and medical conditions that can cause drug interactions. For this reason, before starting with the treatment, inform your doctor if you have the following conditions:
- Pregnant, planning for a pregnancy, or if you are nursing a baby
- If you are taking any medications, supplements, or vitamins whether prescribed or non-prescribed
- If you have allergies to food, medicine, and other substances
- A past medical history of thyroid disorders, low levels of calcium in the blood, high cholesterol issues, problems related to blood clotting, bone infection, pancreatic disorders, dialysis, and other kidney-related problems.
- If a part of your small intestine has been removed
- If you have a malabsorption syndrome
- If you have received any chemo or radiation therapy
- If you cannot take vitamin D supplements or calcium
- If you have poor dental health
Denosumab should be used exactly as prescribed by the doctor or you can check the label of the medicine for more detailed information on its usage and dose. Denosumab should be injected or administered by the doctor or nurse. Moreover, avoid missing or skipping any dose of this medicine.
Denosumab comes in the form of a solution or liquid that is injected anywhere in the upper arm, stomach area, and upper thigh. When denosumab is given to treat bone loss in men or women due to a certain type of cancer, it should be given once in every six months. When this medicine is given to reduce fractures caused by cancer, which has spread to the bones, then the drug is given once in every four weeks. The doctor would also prescribe certain calcium and vitamin D supplements while you are taking this drug. The supplements should not be missed and should be taken exactly as prescribed by the doctor.
Denosumab can cause jaw problems in certain individuals and the risk increases if that individual is already suffering from cancer, poor dental health, or other conditions. Hence, before starting denosumab, talk with the doctor to carry out a detailed dental checkup. While you are taking denosumab, ensure that you take care of your teeth by maintaining a healthy dental habit.
Ensure to have periodical checkups with the dentist. There have been certain cases reported that patients who were on denosumab have complained of fracture in the thigh bone or femur. Some of these patients were already taking another medication called prednisone, which is a glucocorticoid. Inform the doctor right away if you sense any kind of pain in your groin, thigh, or hip.
Patients may also experience low levels of calcium while being treated with denosumab. If the case is severe, then it can be fatal as well. Immediately ask for medical attention if you experience the following symptoms:
- Stiffness in the muscles
- Muscle twitching
- Muscle cramps
- Burning sensation
- Tingling sensation in the toes, face, or mouth
Denosumab should not be given to small children since the drug tends to affect the growth and development of their bones.
The common side effects of denosumab are:
- Loss of appetite
- Pain in the joints
- Back pain
- Red or itchy skin
- Peeling of the skin
The severe cases of denosumab side effects include:
- Pain in the groin and thigh
- Pain in the chest or chest tightness
- Swelling of the face, lips, and mouth
- Symptoms of low levels of calcium in the blood such as spasms
- Muscle twitching or cramps
- Jaw problems such as drainage from the mouth or teeth
- Mouth sores or ulcers
- Symptoms of low level of phosphate in blood such as muscle pain
- Weakness of the muscles
Zoledronic Acid (Zometa)
Zoledronic acid is used for treating high levels of calcium in the blood, which can lead to the occurrence of cancer. Zoledronic acid can also be used with other types of medications to treat patients who are suffering from certain types of cancer. This medication is a bisphosphonate, which works by reducing the causes that lead to the breakdown of the bone. This, in turn, decreases the levels of calcium, which are released into the blood from the bones.
Ultimately, it lowers the level of calcium in the blood. Do not take zoledronic acid if you are allergic to any of the contents present in the medicine. Avoid this drug if you have a severe form of kidney disease along with having a certain type of cancer or any other cancer that has metastasized to the bones and other parts of the body, if you are taking medications that contain certain traces of zoledronic acid or any other kind of bisphosphonate such as alendronate.
Before starting with the treatment of zoledronic acid, there are certain things you should inform the doctor about:
- Let the doctor know if you are pregnant, planning for a pregnancy, or nursing a baby.
- If you are taking any kind of medications, supplements, or vitamins whether prescribed or non-prescribed.
- Allergy to any kind of food, medicine, or any other substances.
- A severe form of allergic reaction to any of the drugs associated with bisphosphonate.
- Issues related to dehydration or low volume of blood.
- Poor dental health or will be undergoing any kind of dental procedure or surgery.
- If you are treated for or will be undergoing chemotherapy or radiation therapy.
- If you are taking any kind of medications for jawbone problems.
- If you have high levels of calcium in the blood.
- Kidney problems
- Heart-related issues
- Liver problems
There can be instances when certain medications can cause drug interactions if used along with zoledronic acid. Take note of the following medications if you are taking zoledronic acid:
- Steroids: Taking steroids such as prednisone or any angiogenesis inhibitors along with zoledronic acid can lead to an increase in the risk of jaw bone related problems.
- NSAIDs, tacrolimus, amphotericin b, and vancomycin: When these drugs are taken along with zoledronic acidharm the kidney and can increase the risk of having other kidney problems. The side effects of zoledronic acid can also increase if these medications are taken.
Always make sure to check with your doctor about any medications that you are taking to avoid drug interactions.
Zoledronic acid is given in the form of an injection. It should be administered under the guidance of a doctor or nurse. Try to avoid missing any doses of this medicine. If you are taking these shots at home, then learn all the usage methods from the doctor. Also check for any particles or discoloration in the solution.
Do not mix zoledronic acid with other IV fluids such as Hartmann’s solution or Ringer’s solution. Check with the doctor for any vitamin D or calcium supplements to be taken along with zoledronic acid. While the treatment of zoledronic acid is going on, try and keep yourself hydrated as much as possible.
The use of zoledronic acid can lead to jawbone problems in certain patients and the risk would increase if this medicine is taken for a longer duration or if the individual is suffering from cancer or from poor dental hygiene. Check with the doctor on how to avoid such issues prior to starting the treatment with zoledronic acid. Ensure to timely brush and floss your teeth to avoid any dental problems.
Certain patients using zoledronic acid have reported thigh bone fractures. The cause of this issue is still unknown. However, make sure to check with the doctor if you experience any kind of pain in the groin, thigh, or hip.
The common side effects of zoledronic acid are:
- Back pain
- Sore throat
- Mild cough
- Stomach upset
- Having trouble sleeping
- Weight loss
- Mild joint and muscle pain
- Mental changes
These symptoms are usually mild and tend to go away in few days. However, if they worsen, then inform the doctor immediately. The severe side effects of zoledronic acid are:
- Reduction in the sense of touch
- Mental changes such as feelings of depression and anxiety attacks
- Slow or irregular heartbeat
- Pain and swelling in the jaw
- Vision changes or blurry vision
- Slight changes in the amount of urine passed
- Swelling of the ankles and feet
- Eye and mouth dryness
- During the course of treatment in breast cancer, certain medication or therapies can lead to bone loss. In some cases, cancer can spread to the bones as well.
- Fosamax and Actonel are commonly available bisphosphonates for treating bone-related issues on cancer patients.
- Evista and targeted therapies are also known medications to treat bone problems in breast cancer.