Table 2.
The main treatment strategies for cancer bone metastasis
| Therapy | Application | Examples |
|---|---|---|
| Hormone therapies | ||
| SERM | Standard endocrine therapy for estrogen receptor-positive BC patients | Tamoxifen, raloxifene, and toremifene |
| AI | As monotheray or the extended adjuvant AI treatment after tamoxifen | Letrozole, anastrozole, and exemestane |
| Androgen deprivation therapy (ADT) | Standard treatment of PC patients with distant metastases | Antiandrogens, orchiectomy, GnRH agonists or antagonists |
| Radioisotopes | ||
| β-emitting radioisotopes | Bone pain relief in PC patients | 89Sr, 135Sm |
| α-emitting radioisotope | Treatment of CRPC patients with symptomatic bone metastases | 223Ra |
| External beam radiation therapy (EBRT) | Prevents potential bone fractures and focal bone pain | |
| Surgery | Local adjuvant therapy combined with radiation therapy and embolization | Osteosynthesis and prosthetic implant insertion |
| Bisphosphonates | ||
| Nitrogen-containing bisphosphonate (N-BP) | Prevents bone metastases in BC patients | ALN, ZOL, pamidronate |
| Non-nitrogen-containing bisphosphonates | Reduces bone metastases in BC patients during the 5-year follow-up | Clodronate, etidronate |
| Novel therapies | ||
| RANK/RANKL inhibitor | Prevents bone metastases of BC and PC | Denosumab, OPG |
| CXCL12/CXCR4 inhibitor | Works in synergy with chemotherapy, radiation, or anti-VEGFR therapies | Anti-CXCL12 antibody |
| TGF-β inhibitor | Reduces tumor growth and bone metastases especially in triple-negative BCs | LY2109761, BMP7 |
| HMGR inhibitor | Reduce osteolytic bone metastases of lung cancers | Simvastatin |
SERM selective estrogen receptor modulator, GnRH gonadotropin-releasing hormone, CRPC castration-resistant prostate cancer, ALN alendronate, ZOL zoledronic acid, AI aromatase inhibitor, 223Ra radium-223, 89Sr strontium-89, 135Sm samarium-135, BC breast cancer, PC prostate cancer, HMGR HMG-CoA reductase