RATIONALE: Nearly 50% of patients with bone metastases develop one or more complications collectively termed skeletal-related events (SREs). The study herbal medicine might reduce the morbidities due to "Skeletal-related events" (SRES), and extend survival time.

PURPOSE: the study is to explore the effects of the 4 Herbs Formula on the reduction of "Skeletal-related events" (SRES), and survival time.

OBJECTIVES:

Primary Primary efficacy end points are SRE, general state and biomarkers. Secondary Survival rate and survival time Time to first SRE (since randomization) Biochemical markers Quality of Life: EQ5-D Pain control (Brief Pain Inventory)

OUTLINE:

Patients will be randomized to receive either 4 herbs formula plus Zometa or Zometa alone after all the eligibility criteria have been fulfilled and informed consent has been signed.

Inclusion Criteria:

• Aged 18 years or older
• Breast cancer bone metastasis-no supplementary treatment or hormonal treatment alone
• Confirmed diagnosis of metastatic breast cancer
• Radiographic proof of metastatic bone disease
• Informed consent obtained

Exclusion Criteria:

• Known history of primary bone tumors (benign and/or malignant)
• Prior use of bone modifying agents, including but not limited to zoledronic acid or denosumab within 12 months of study entry
• Active anti-cancer therapies in the form of cytotoxics or targeted therapies. [Patients who are currently on hormonal therapies, including but not limited to tamoxifen, aromatase inhibitors and LHRH agonists/antagonists are allowed for study entry. Clarifications shall be sought from investigators if in doubt].
• Significant drug hypersensitivity
• No informed consent signed