**3. Management of bone health in early breast cancer**

The most common breast cancer subtype is luminal cancer with positive estrogenand progesterone-receptor (ER/PR) expression. Around 50% of all human epidermal growth factor receptor 2 (HER2)-enriched subtypes also express estrogen ER and progesterone PR [10]. These hormonal receptor (HR)-positive cancers are clearly estrogen-driven malignancies; however, estrogen also has a protective effect on bone, and reduced levels can trigger bone loss. Hormonal therapy with aromatase inhibitors (AI) (usually anastrozole, exemestane, or letrozole) represents standard of care in early postmenopausal and in high-risk pre-menopausal patients. In the latter group they are usually administered in combination with a gonadotropin-releasing-hormone receptor antagonist (GnRH-A).

In the postmenopausal patients, use of aromatase inhibitors is shown to lead to a bone mineral density loss of about 2% per year, while in combination with GnRH analogues, bone mineral density loss can reach even 7% and more [11].

Real world data looked at patterns of bone loss in women with breast cancer [12]. In this particular analysis, bone mineral density of patients was significantly decreased in the lumbar spine (6.8%), followed by femoral neck (4.6%), and hip (3.5%). Bone loss seemed to be greatest in the first year.

Chemotherapy was also associated with bone loss at all sites, and the premenopausal status at moment of diagnosis was significantly associated with bone loss in the lumbar spine. No significant relationship between health behavior status and bone mineral density change could be demonstrated.

Based on different guidelines including National Comprehensive Cancer Network (NCCN), European Society of Medical Oncology (ESMO), and the Swiss SVGO (Swiss Association Against Osteoporosis), patients with early-stage breast cancer should receive comprehensive care measures focusing on bone metastasis prevention. This includes regular bone scans (DEXA Scans), life style modifications, calcium and vitamin D supplementation, and bisphosphonates.

**Figure 1** demonstrates general practical guidelines in breast cancer and other cancer subtypes. Our own data [2] showed treatment adherence in only 75% of patients with breast cancer (small single center analysis).

*Perspective Chapter: Management of Bone Health in Breast Cancer Patients DOI: http://dx.doi.org/10.5772/intechopen.109030*

### **Figure 1.**

*Treatment recommendation for bone health in cancer patients. Demonstrated bone health guidelines for patients with breast cancer and other cancers, under endocrine therapy. Adapted from Coleman R. [13, 14].*
