Cancer cells in the blood can now be isolated and studied in culture, opening up the possibility of personalizing treatment strategies.
Tumours shed small amounts of cancer cells into the bloodstream, but it has been difficult to isolate and grow these cells. Shyamala Maheswaran and Daniel Haber of Massachusetts General Hospital in Boston and their colleagues developed an improved microfluidic system that filters out normal blood cells, leaving tumour cells unharmed.
The team used the device to harvest circulating tumour cells from the blood of patients with advanced breast cancer. These were then grown in culture (pictured) and sequenced to reveal key mutations in certain cancer genes. The researchers also tested the cells' sensitivity to various drugs.
With further improvements, the technique could one day be used to guide therapy, the authors say.