Bisphosphonates have become an integral component of cancer treatment in patients who have metastatic bone disease. Bisphosphonates reduce the morbidity of metastatic bone disease, mainly by decreasing the prevalence of SREs [1,2].
In addition, bisphosphonates are widely used for the prevention and treatment of bone loss (osteoporosis), both treatment-related and non-treatment-related.This includes the osteoporosis associated with aromatse inhibitors.
Bisphosphonates decrease bone resorption and increase mineralization by inhibiting osteoclast activity [1,3].
There are two classes of bisphosphonates, non-nitrogen containing and nitrogen containing, with somewhat different effects in killing osteoclast cells. The nitrogen containing bisphosphonates are more potent osteoclast inhibitors. Etidronate, clodronate, and tiludronateare non-nitrogen containing bisphosphonates, and the nitrogen containing bisphosphonates include pamidronate, alendronate, ibandronate, risedronate, and zoledronic acid.
Bisphosphonates have a direct apoptotic effect on osteoclasts, affect their differentiation and maturation, and thereby act as potent inhibitors of bone resorption. In preclinical models, the bisphosphonates have also been shown to influence macrophages, gamma delta T cells, osteoblasts, and tumor cells.
In addition to their effects on osteoclast inhibition, bisphosphonates may also have antitumor and/or antiangiogenic effects, but this is a controversial area. Investigations are ongoing to better define the clinically relevant effects of bisphosphonates in patients with cancer [4,5]
Quality of evidence and Clinical efficacy:
Definition of Skeletal Related Events:-
Breast cancer—For patients with breast cancer and bone metastases, bisphosphonate therapy can prevent and/or delay skeletal complications, and palliate bone pain. A survival benefit has not been shown. In women with metastatic breast cancer without clinically evident bone metastases, bisphosphonates do not reduce the incidence of sk…………………………..