Distribution of bony metastases in prostatic carcinoma. Fifty-five prostate cancer and 55 breast cancer patients with positive bone scintigrams were studied. The pattern of spread in the axial skeleton and pelvis showed differences between the 2 groups. This difference was not related primarily to bone volume at the site of metastasis. The difference in distribution of bony metastases between breast and prostate is explained by our knowledge of Batson's vertebral venous plexus. 