A new nanotechnology tool allows for a more effective biopsy which scientists believe will aid in earlier cancer detection. "The device works at the nanoscale level to efficiently identify free-floating cancer cells and could aid both cancer research and treatment, scientists say. Circulating tumor cells, or CTCs, play a crucial role in cancer metastasis, which is the most common cause of cancer-related death in patients with solid tumors. Metastasis occurs when marauding CTCs leave the primary tumor site and travel through the blood stream to set up colonies in other parts of the body."