Microfluidic Chip Snags Cancer Cells

In cancer patients, circulating tumor cells (CTCs) in the blood are the hallmark of the spread of the disease. But these cells are rare and difficult to isolate. Medical engineer Mehmet Toner and coworkers at Massachusetts General Hospital and Harvard Medical School have now come up with a microfluidic device that isolates CTCs from whole blood samples (Nature 2007, 450, 1235). The CTC chip consists of an array of micrometer-scale posts coated with antibodies against a molecule found on the surface of epithelial cells from various organs but not on blood cells. The researchers used the device to capture CTCs in blood samples from patients with lung, prostate, pancreatic, breast, or colon cancer. They were able to distinguish CTCs from blood cells and further analyze the captured CTCs for tumor-specific markers. In follow-up samples, the CTC measurements correlated with patients' response to treatment. The microfluidic device could become a tool for monitoring cancer treatment, for detecting relapses, and eventually for early detection, Toner says.