Biology of breast cancer bone metastasis.

Breast carcinoma ranks among the most prevalent malignancies in women. Breast carcinoma frequently metastasizes to bone and approximately 70% of patients with breast cancer have bone metastases, which generally are osteolytic lesions. They cause major morbidity and mortality in patients; and the available treatment options are limited. Bone-specific homing and colonization of cancer cells are important and interesting features of metastasis. There are complex and multiple steps in the process of bone metastasis; and the elaborate interaction between breast carcinoma and bone involves various cytokines, growth factors and cellular signals, which results in a vicious cycle and promotes tumor cell accumulation and osteolysis. Recent advances in molecular biology have resulted in major breakthroughs in our understanding of the pathogenesis of bone metastasis in breast cancer, which is critical in preventing metastasis, designing novel and targeted treatments and prolonging survival in this devastating condition.