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How to Live Longer with Bones that are Stronger
Felix O. Kolb, MD and Ernest H. Rosenbaum, MD
How Common is Osteoporosis and Who is at Risk?
How Do You Discover Osteoporosis?
How Do You Prevent and Treat Osteoporosis?
Osteoporosis and Cancer Therapy
Most people consider it natural that our bones grow weak with age. A long-term diet with calcium and vitamin D supplements and a weight-bearing exercise program designed to promote and maintain bone strength may help to offset the increased bone-tissue breakdown that begins in middle age. Without such preventive measures, bones can become porous, brittle, and ultimately subject to spontaneous fractures. This gradual bone loss is called osteoporosis, and for women, it will accelerate after menopause.
Osteoporosis is responsible for more than 1.5 million fractures annually, mostly of the hip, spine, and wrist. Ten million Americans already have osteoporosis and 34 million more have a low bone mass, placing them at increased risk for osteoporosis. Eighty percent of those affected by osteoporosis are women. It is called a silent disease, because it takes many years to develop, and most sufferers do not learn that they have the disease until middle age or later. It commonly afflicts women past menopause. Senile osteoporosis occurs much later in life and affects both sexes.
One out of every two women and one in four men over 50 will have an osteoporosis-related fracture in their lifetime. Five percent of women over 80 will fracture a hip each year, and 20% of these will then die within a year. Forty thousand people will die each year of complications following osteoporosis-associated fractures. The annual medical costs associated with osteoporosis total between 14 and 18 billion dollars.
Osteopenia and osteoporosis (weak bones) are common problems associated with age and cancer survivorship. In most cases, breast and prostate cancer survivors have good skeletons before treatment, which then become osteoporotic with hormone deprivation therapy (ovarian failure and androgen hormone ablation). Such survivors need to follow a calcium rich diet with calcium supplements and vitamin D as well as seek guidance from their healthcare providers for possible drug treatment.
Aside from increasing age, other risk factors include:
The Shrinking Woman
Being female and postmenopausal
Being chronically underweight
Being Caucasian or Asian
Past history of scant or prolonged absence of periods (amenorrhea)
Having a family history of osteoporosis
A poor diet lacking minerals, especially calcium
Lack of weight-bearing exercise
Smoking, drinking alcohol in excess, taking excess caffeine, and certain drugs such as cortisone, thyroid hormone, and anti-convulsants
Routine x-rays and blood and urine tests are not adequate in uncovering osteoporosis. Loss of height and development of so-called dowager's hump are late developments. It is now possible to discover mineral loss early by the use of Dual Energy X-ray Absorptiometry (DEXA or DXA), which can measure bone mineral content at the wrist, the spine and the hip (the most common sites of fracture) accurately with little discomfort, rapidly, and at reasonable cost with minimal exposure to x-rays. (Medicare has approved repeat bone density every 2 years.)
A preventive program started in childhood and continued throughout life will help prevent and/or delay the onset of osteoporosis. By building bone early life you will be able to withstand bone loss later.
- A long-term preventive program to promote bone strength for a lifetime includes:
- 1.A well-balanced diet with calcium and vitamin D supplements.
2.An exercise program emphasizing weight-bearing activities.
The diet must contain calcium rich foods in balance with phosphorous and protein, with vitamin D to help in its absorption. Supplementation with calcium carbonate or calcium citrate may be needed to achieve the recommended daily allowance of 1000-1200 mgs (in divided doses twice a day). Vitamin D in doses of 800-1,000 International units is usually necessary for maintenance. Weight-bearing exercise should be a part of your daily life: walking, cycling, dancing, weight lifting and moderate jogging. The combination of adequate calcium and regular exercise will stimulate and maintain bone mineral content. Giving up smoking and heavy alcohol intake is mandatory.
Dairy and Non-Dairy Sources of Calcium Food Serving Size Calcium (mg) Food Serving Size Calcium (mg) Milk Fish Evaporated
Yogurt, low fat/non fat
Sardines, with bones
Salmon, with bones
Cheese Vegetables (cooked) Parmesan
Ricotta, part skim
Cottage cheese, low fat
When premature menopause occurs - especially after oophorectomy or hysterectomy (removal of the uterus and ovaries) - estrogen therapy is necessary to help prevent osteoporosis. Estrogen treatment of natural menopause likewise slows the accelerated bone loss in women past 50. Low-dose estrogen is the most effective physiologic hormone means of prevention and treatment of advancing postmenopausal osteoporosis. Recent evidence that long-term estrogen/progesterone therapy increases the risk of heart attacks and strokes makes it proper to limit their use to one to five years. If breast or uterine (endrometrial) cancer is a problem, hormone therapy should be discussed with your doctor. If estrogens are contraindicated (e.g., women past the age of 75 or with past history of breast or uterine cancer) other drugs, such as nasal calcitonin, and the bisphosphonate drugs: oral Fosamax (Alendronate), Actonel (Risedronate), Boniva (Ibandronate), or the IV bisphosphonates (Zometa or pamidronate) are now used and have shown progressive increases in bone mass, with reduction of fracture rates, similar or greater than estrogens, for periods up to 10 years. In patients with severe osteoporosis, the use of injectable parathyroid hormone (Forteo) can restore bone mass.
The most potent bisphosphonates, Zometa and Pamidronate, rarely have caused jaw necrosis, which is usually associated with poor dentition or recent tooth extractions. This problem merits a special dentist preventive examination and treatment attention if needed.
Diet education plus exercise and, in many patients, hormonal and other drug therapy can result in major improvement in bone mineral density status in our population. It is easier to prevent osteoporosis early than to treat the advanced disease when fractures have occurred.
Eat a balanced diet, exercise regularly, take daily calcium and Vitamin D supplements, and discuss with your physician the need for hormonal replacement and other measures to prevent or increase your bone mass. Pharmacological measures are available to us now which make it possible both to prevent bone loss once started, and to reverse it once it has progressed to cause fractures. A program for severe compression fractures of the spine by injecting a plastic material into the vertebrae can restore their height and relieve bone pain.
Osteoporosis and Breast Cancer Endocrine Therapy
The original treatment for metastatic breast cancer (1898) was surgical oophorectomy (removal of the ovaries) or later in 1900's radiation ablation (loss of function) of the ovaries to stop estrogen production.
Adjuvant and therapeutic chemotherapy, radiotherapy, or hormonal ablation can also reduce or stop ovarian function and thus reduce or stop estrogen production. This can result in premature bone loss. Adjuvant Tamoxifen therapy can help improved overall and disease-free survival but is less effective than the selective aromatase inhibitors. Tamoxifen also has some protective effect on bone density, greater in postmenopausal rather than in premenopausal women.
Osteoporosis and the Selective Aromatase Inhibitors for Breast Cancer
Selective aromatase inhibitors are a new class of drugs for postmenopausal patients for adjuvant as well as metastatic breast cancer therapy. The three types of aromatase inhibitor drugs - anastrozole (Arimidex) and letrozole (Femara) are non-steroidal, and exemestane (Aromasin) - (a steroidal drug) - are irreversible inhibitors of the aromatase enzyme, but also increase bone resorption.
Another drug is the selective estrogen-receptor modulators (SERMs), Evista (Raloxifene), which acts as an estrogen antagonist against hormone positive breast cancer, and can help reduce the risk of invasive breast cancer. The FDA Oncology Drug Advisory Committee (NCI Cancer Bulletin for August 2007) recommended approval of raloxifene to prevent breast cancer in women with osteoporosis based on results from four studies, including the pivotal STAR trial which showed raloxifene was as effective as tamoxifen in reducing the breast cancer risk (prevention) in postmenopausal women. The STAR trial showed raloxifene and tamoxifen reduced the risk of invasive breast cancer approximately 50%. Raloxifene had a better safety profile with fewer blood clots, endometrial cancer and cataracts similar to estrogen. Raloxifene (Evista) helps reduce the risk of osteoporosis.
Osteoporosis and Prostate Cancer
Following prostate cancer androgen hormone ablation treatment, osteoporosis may occur even in as short a period as six months to two years due to a decrease in testosterone either by hormone treatment (GnRH agonist - Lupron) or orchiectomy (surgical removal of testicles). Treatment for osteoporosis/osteopenia is the same as for breast cancer (diet, calcium, Vitamin D, weight-bearing exercises and bisphosphonates [Zometa or Pamidronate] as needed to prevent bone loss.)
Cancer, Osteoporosis, and Bone Density Treatment for Metastases
Bone metastases from breast or prostate cancer are common. Bone resorption is accelerated, leading to an increased vertebral, hip and wrist and bone fracture rate. Treatment for osteoporosis/osteopenia includes diet, calcium, Vitamin D, exercise with caution to avoid a bone fracture and bisphosphonates [Zometa or Pamidronate] to protect bones from the reabsorptive activity of cancer metastases.
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