Tuesday, September 15, 2009

Treating Bone Loss in Breast Cancer Survivors

Cancer Drugs Aren't the Only Culprits

MAYWOOD, Il. -- Osteoporosis is a growing concern among breast cancer survivors and their doctors, because certain cancer drugs can cause bone loss.

Many breast cancer patients also experience secondary causes of bone loss, such as vitamin D deficiency.

But a Loyola University Health System study has found that bone loss can be halted with a comprehensive regimen that includes both osteoporosis drugs and treatments that target secondary causes of bone loss.

The study by Dr. Pauline Camacho and colleagues was presented at the annual meeting of the American Society for Bone and Mineral Research.

"Doctors evaluating breast cancer patients for possible bone loss should look further than cancer drugs," Camacho said.

Primary causes of osteoporosis are menopause and aging. Secondary causes are diseases or conditions that exacerbate bone loss.

A class of breast cancer drugs called aromatase inhibitors can decrease bone mineral density and increase the risk of fractures in postmenopausal women. The drugs decrease the body's production of estrogen. While estrogen feeds cancer, the hormone also protects against osteoporosis. In certain breast cancer patients, bone loss from cancer drugs can be treated with osteoporosis drugs called bisphosphonates, such as alendronate sodium (Fosamax®) and ibandronate sodium (Boniva®).

Camacho and colleagues reviewed charts of 81 consecutive breast cancer patients who were referred to Loyola's Osteoporosis and Metabolic Bone Disease Center for treatment or prevention of osteoporosis. Fifty-one patients had secondary causes of bone loss, including Vitamin D deficiency (65 percent), excessive calcium excretion in urine (16 percent) and an overactive parathyroid gland (13 percent). Thirty patients did not have secondary causes of bone loss.

Each group received similar treatment with osteoporosis drugs. Women with secondary bone loss also received additional treatments. For example, vitamin D deficiency was treated with prescription doses of vitamin D supplements. Excessive calcium excretion was treated with a "water pill" that's also used to treat high blood pressure. There were various treatments for parathyroid gland disorder, depending on the cause.

After one year, the breast cancer patients with secondary causes of bone loss had stable bone mineral density in their spines and necks. Bone mineral density improved in the group of breast cancer patients who did not have secondary causes of bone loss. (Bone mineral density -- the amount of calcium and other minerals packed into a segment of bone -- predicts osteoporosis.)

Camacho said the study demonstrates that bone loss "can be prevented in women undergoing hormonal therapy if secondary causes of bone loss are corrected and bisphosphonate osteoporosis drugs are appropriately used." Camacho is an associate professor of medicine at Loyola University Chicago Stritch School of Medicine and director of Loyola's Osteoporosis and Metabolic Bone Disease Center.

Camacho's co-authors are Dr. Kathy Albain, Dr. Patricia Robinson and Stritch medical student Naseem Helo. Albain is a professor and Robinson is an assistant professor at Stritch. Both are in the department of medicine, division of hematology/oncology.

About Loyola University Health System

Loyola University Health System (LUHS) is part of Trinity Health. Based in the western suburbs of Chicago, LUHS is a quaternary care system with a 61-acre main medical center campus, the 36-acre Gottlieb Memorial Hospital campus and more than 30 primary and specialty care facilities in Cook, Will and DuPage counties. Loyola University Medical Center’s campus is conveniently located in Maywood, 13 miles west of Chicago’s Loop and 8 miles east of Oak Brook, Ill. At the heart of the medical center campus is a 559-licensed-bed hospital that houses a Level 1 Trauma Center, a Burn Center and the Ronald McDonald® Children's Hospital of Loyola University Medical Center. Also on campus are the Cardinal Bernardin Cancer Center, Loyola Outpatient Center, Center for Heart & Vascular Medicine and Loyola Oral Health Center as well as Loyola University Chicago Stritch School of Medicine, Loyola University Chicago Marcella Niehoff School of Nursing and the Loyola Center for Fitness. Loyola's Gottlieb campus in Melrose Park includes the 255-licensed-bed community hospital, the Professional Office Building housing 150 private practice clinics, the Adult Day Care, the Gottlieb Center for Fitness, Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park.

Trinity Health is a national Catholic health system with an enduring legacy and a steadfast mission to be a transforming and healing presence within the communities we serve. Trinity is committed to being a people-centered health care system that enables better health, better care and lower costs. Trinity Health has 88 hospitals and hundreds of continuing care facilities, home care agencies and outpatient centers in 21 states and 119,000 employees.