Batson's veins are veins that connect the pelvic veins (draining the inferior end of the urinary bladder and prostate) to the internal vertebral venous plexus. They allow metastasis of cancer from pelvic organs to vertebral column. Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... In anatomy, the urinary bladder is a hollow, muscular, and distensible (or elastic) organ that sits on the pelvic floor in mammals. ... The prostate is a compound tubuloalveolar exocrine gland of the male mammalian reproductive system. ... Metastasis (Greek: change of the state) is the spread of cancer from its primary site to other places in the body. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... The vertebral column seen from the side Different regions (curvatures) of the vertebral column The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ...