Chemotherapy can cause severe bone loss in many premenopausal women receiving adjuvant (preventative) chemotherapy after surgical removal of a primary breast cancer, according to a study in the Journal of Clinical Oncology (Vol. 19, No. 14: 3306-3311).

With more women considered candidates for adjuvant therapy, the question regarding bone loss is significant for breast cancer survivors.

One of chemotherapy’s side effects is ovarian failure, or early menopause, which can lead to osteoporosis, or thinning of the bones. This makes women more susceptible to fractures.

In a new study looking at osteoporosis in these women, researchers found that significant bone loss occurred in as little as six months following adjuvant chemotherapy.

Charles L. Shapiro, MD, associate professor of internal medicine and director of breast medical oncology at the Arthur G. James Cancer Hospital and Richard J. Solove Research Institute in Columbus, Ohio, and colleagues, evaluated 49 premenopausal women with stage I and II breast cancers who had received chemotherapy.

"The main purpose of this work is to raise awareness of this issue," Shapiro says. "It is an important survivorship issue."

The women in the study were evaluated for ovarian failure within four weeks of starting chemotherapy, and then six and 12 months after starting chemotherapy. Signs of ovarian failure include lack of menstruation, bone loss, and changes in levels of hormones such as estrogen.

Thirty-five of the 49 women were determined to have ovarian failure, and of those women, highly significant bone loss was found in their lumbar spine and femur, or hip, by six months. Their bone mineral density decreased further at 12 months. In contrast, according to the authors, women who retained menstrual function had no significant decrease in bone density, except for a 2% decrease in the hip.

"This is the first study to demonstrate significant loss of bone as early as six months," Shapiro tells ACS News Today.

He advises women who have chemotherapy-induced ovarian failure to have a bone density scan to determine whether they are at risk of developing osteoporosis. They also should receive adequate calcium and D vitamin supplementation, and perform moderate weight-bearing exercise such as walking on a regular basis, Shapiro recommends.

Marilyn Leitch, MD, professor in the division of surgical oncology at the University of Texas Southwestern Medical Center in Dallas, says women who have signs of bone loss after receiving chemotherapy for breast cancer also may want to talk to their doctors about taking medications for osteoporosis. Products on the market include bisphosphonates such as Fosamax and hormonal agents such as Miacalcin.

Some physicians are reluctant to give breast cancer survivors hormone replacement therapy to prevent osteoporosis because it is unclear whether there is a link between hormone therapy and breast cancer.

"Quality-of-life issues such as maintained bone strength are becoming more recognized as issues to be addressed in breast cancer survivors," she says. Because of that concern, "osteoporosis monitoring and prevention are being included in [breast cancer] clinical trials."