Cancer stem cells are considered the "Seed" or the "root" of the cancer, and like chopping down a tree, if you dont remove the root, the cancer grows back. Cancer stem cells are resistant to chemotherapy and radiotherapy. Therefore if there was a way to selectively purify or extract cancer stem cells, it would make it a lot easier to develop agents that kill them.
The current patent covers means of identifying tissue specific stem cells in the breast, as well as breast cancer stem cells through selecting for cells that express the LRP5 receptor.
In its broadest claim, the patent covers "A method for enriching a population of mammary cells or mammary tumor cells for somatic mammary stem cells or mammary tumor stem cells, the method comprising the steps of: obtaining a population of mammary cells or mammary tumor cells containing one or more somatic mammary stem cells or mammary tumor stem cells; contacting said population of mammary cells or mammary tumor cells with an anti-low density lipoprotein receptor-related protein 5 (LRP5) antibody; and selecting cells that bind to the antibody. "