Bone metastasis

According to literature reports, more than one million new cancer patients are diagnosed in the United States each year, and about 50% of these patients eventually develop bone metastases.Most of the bone metastases occur in the central axis and lower limbs, especially in the hip joint area. The tumors prone to bone metastasis were breast cancer (73.1%), lung cancer (32.5%), kidney cancer (24%), rectal cancer (13%), pancreatic cancer (13%), gastric cancer (10.9%), and colon cancer ( 9.3%), ovarian cancer (9%), other common primary cancers of bone metastasis and prostate cancer. Bone metastases occurred in the spine most, followed by long bones of the pelvis and lower limbs, and knee and elbow joints far less common. The formation of bone metastases is the result of hematogenous metastasis of primary cancer, and the interaction between tumor cells and the host. The more widely recognized metastasis methods are: ① primary tumor cells infiltrate surrounding tissues into the vasculature (blood and lymph); Shedding and release in the blood circulation; ③ tumor cells stay in the blood vessel wall in the bone marrow; ④ tumor cells escape the blood vessels through the endothelial cells, and then proliferate outside the blood vessels;