Bone Cancer

Researchers from University of Sydney, ANZAC Research Institute provide details of new studies and findings in the area of breast cancer therapy

Bone Cancer Library Library Home This article was published in Clinical Oncology Week, which you can subscribe to online.

"However, there is no direct evidence that high bone turnover is causally associated with the establishment and progression of metastases. In this study, we investigate the effects of high bone turnover in a model of breast cancer growth in bone. Female nude mice commenced a diet containing normal (0.6%; 'Normal-Ca') or low (0.1%; 'Low-Ca') calcium content. Mice were concurrently treated with vehicle or osteoprotegerin (1 mg/kg/d s.c; n=16 per group). Three days later (day 0), 50,000 Tx-SA cells (variant of MDA-MB-231 cells) were implanted by intratibial injection. On day 0, mice receiving Low-Ca had increased serum parathyroid hormone (PTH) and tartrate-resistant acid phosphatase 5b levels, indicating secondary hyperparathyroidism and high bone turnover, which was maintained until day 17. Osteoprotegerin increased serum PTH but profoundly reduced bone resorption. On day 17, in mice receiving Low-Ca alone, lytic lesion area, tumor area, and cancer cell proliferation increased by 43%, 24%, and 24%, respectively, compared with mice receiving Normal Ca (p <0.01). Osteoprotegerin treatment completely inhibited lytic lesions, reduced tumor area, decreased cancer cell proliferation, and increased cancer cell apoptosis. Increased bone turnover, due to dietary calcium deficiency, promotes tumor growth in bone, independent of the action of PTH. Breast cancer patients frequently have low dietary calcium intake and high bone turnover," wrote Y. Zheng and colleagues, University of Sydney, ANZAC Research Institute.

The researchers concluded: "Treatment to correct calcium insufficiency and/or treatment with antiresorptive agents, such as osteoprotegerin, may be of benefit in the adjuvant as well as palliative setting."

Zheng and colleagues published their study in Cancer Research (Accelerated bone resorption, due to dietary calcium deficiency, promotes breast cancer tumor growth in bone. Cancer Research, 2007;67(19):9542-8).

For additional information, contact Y. Zheng, University of Sydney, Bone Research Program, ANZAC Research Institute, Sydney, New South Wales, Australia.

The publisher's contact information for the journal Cancer Research is: American Association Cancer Research, 615 Chestnut St., 17TH Floor, Philadelphia, PA 19106-4404, USA.

Keywords: Australia, Sydney, Breast Cancer Therapy, Bone Cancer, Bone Resorption, Breast Cancer, Breast Carcinoma, Cancer Research, Oncology, Women's Health.

This article was prepared by Clinical Oncology Week editors from staff and other reports. Copyright 2007, Clinical Oncology Week via NewsRx.com.