A new chip with a labyrinth design promises big improvements in detecting rare and aggressive cancer cells in the blood, helping doctors to anticipate tumour growth and plan customised treatments for their patients.
By controlling the flow of the blood through this micro-maze, the chip is able to separate out larger types of cells, including cancer cells and cancer stem cells known to be particularly malignant and resistant to drugs.
Such cancer cells can be one in a billion in a flow of normal white blood cells, and the new method is more effective and faster than current techniques at finding its targets, according to the team from the University of Michigan.
"You cannot put a box around these cells," says lead researcher Sunitha Nagrath. "The markers for them are so complex, there is no one marker we could target for all these stages."
These cancer cells occasionally get dislodged from cancerous tumours in the body, floating freely in the bloodstream, and they can reveal clues about the original growth – if they can be caught.
The cells are also thought to sometimes transform into cancer stem cells (CSCs), types of cells that can grow and feed new tumours, which is another reason scientists are keen to keep a close eye on them.