Test for Cancer Cells in Blood
An inexpensive microfluidic chip could lead to earlier cancer detection and treatment.

Source: “Isolation of rare cultivating tumour cells in cancer patients by microchip technology”
Mehmet Toner et al.
Nature 450: 1235-1239

Results: A microfluidic device designed by researchers at Massachusetts General Hospital in Boston can detect very low blood levels of cells from malignant tumors. In initial tests, the low-cost device detected such cells in the blood of all but one of 116 patients with various types of cancer.

Why it matters: A malignant tumor continually sheds cells into the bloodstream, spreading cancer to other tissues. Changes in the number of circulating cancer cells indicate changes in the size of the tumor during treatment. A cheap way to detect and monitor those cancer cells could allow doctors to regularly assess the effectiveness of treatment, as they do by measuring levels of viral RNA in HIV patients. Researchers can also examine cells captured on the microfluidic chip for molecular markers that suggest a more aggressive form of cancer or a type of tumor that will respond to specific drugs.

Methods: The device consists of a business-card-size silicon chip dotted with 80,000 microscopic posts. Each post is coated with a molecule that binds to a specific protein found on most cells originating from solid tumors, such as those found in breast, lung, and prostate cancer. As blood flows through small channels in the chip, tumor cells stick to the posts.

Next steps: Larger clinical trials involving patients with lung and prostate cancer will help determine how best to use the chip.