Novel hybrid device to boost research on metastatic process of breast cancer cells European researchers are working on a novel hybrid device to better understand the metastatic process of cancer cells traveling from breast to bone and fast screen new drugs against it. The spread of cancer cells to other parts of the body, known as metastasis, is the main cause of cancer-related deaths. According to the US National Cancer Institute, in 2018 there were 9.5 million deaths caused by cancer worldwide, and a high percentage of those involved tumors that had spread across the body. However the metastatic process remains one of the most enigmatic aspects of the disease. To understand it, we have to take a step back and look at the biology of the primary tumor.