PHILADELPHIA - A strong skeleton is less likely to be penetrated by metastasizing cancer cells, so a fortified glass of milk might be the way to block cancer’s spread, according to researchers at the ANZAC Research Institute in Concord, Australia. Using a mouse model of breast cancer metastasis, the researchers found that a calcium deficiency may increase the tendency of advanced breast cancer to target bone. Dietary calcium, they reason, might help prevent the spread of breast cancer to bone and serve as an adjuvant treatment during therapy.