New invention can easily spot whether cancer has spread

German researchers have come up with a test that measures how stretchy cells are, which could revolutionise the way doctors spot whether cancers have spread, Inventors at the University of Leipzig have produced a laptop-sized gadget which can give a diagnosis using as few as 50 cells and avoids the need to cut out tissue and say it is 1,000 times more accurate than traditional tests.

The say the same technology could also be used to find stem cells in blood. Cancer cells tend to be more elastic than healthy cells and the technology works by using a special laser beam of unfocused light to stretch and measure individual cells one by one without killing them.

Only 50 tumour cells need to be present in a sample for the optical stretcher to be able to diagnose cancer compared to more traditional methods, such as looking at tissue samples under a microscopy, which needs up to 100,000 tumour cells to be present to make a diagnosis.

According to the researchers,the new technology means only small samples of cells need to be removed from sites around the body using fine needles and then analysed, and the advantage is that it should be able to identify cancers that are about to spread.

Doctors usually check whether a cancer has spread by looking for distant tumours in other parts of the body, away from the original tumour site, and sometimes this is not possible or is it is dangerous to cut out tissue samples from these secondary sites to check for cancer spread.

But cancer experts are stressing that the technology is still in its infancy and would not as yet replace conventional cancer tests.

Professor Josef Kas, lead researcher, says of all the physical properties of a cell, elasticity is the one which varies most dramatically between normal and cancer cells and this makes stretching the most sensitive method known for identifying cancer. The optical stretcher could also be used to separate out stem cells from adult blood, again, based on their elasticity.Stem cells are immature cells that have the ability to become any kind of tissue in the body, scientists can harvest them from embryos, but this has raised ethical concerns. The optic stretcher might help get round this issue.

Professor Peter Sasieni of the UK's Cancer Research, says it has been observed before that cancer cells have a less well defined skeleton than normal cells and so it is reasonable that they would change shape more in response to external forces but he feels talk of a machine that could replace a microscope for cancer screening or the study of lymph nodes to assess tumour spread, is rather premature.

He hopes that the team in Leipzig will collaborate with others to determine the clinical relevance of their highly innovative invention.