Via EurekAlert!: "A cancer vaccine carried into the body on a carefully engineered, fingernail-sized implant is the first to successfully eliminate tumors in mammals ... The new approach [uses] plastic disks impregnated with tumor-specific antigens and implanted under the skin to reprogram the mammalian immune system to attack tumors. The new paper describes the use of such implants to eradicate melanoma tumors in mice. ... [This approach] redirects the immune system to target tumors, and appears both more effective and less cumbersome than other cancer vaccines ... Conventional cancer vaccinations remove immune cells from the body, reprogram them to attack malignant tissues, and return them to the body. However, more than 90 percent of reinjected cells have died before having any effect in experiments. ... The [implants] are 8.5 millimeters in diameter and made of [a] biodegradable polymer. Ninety percent air, the disks are highly permeable to immune cells and release cytokines, powerful recruiters of immune-system messengers called dendritic cells. These cells enter an implant's pores, where they are exposed to antigens specific to the type of tumor being targeted. The dendritic cells then report to nearby lymph nodes, where they direct the immune system's T cells to hunt down and kill tumor cells."