X-ray trick picks out tiny tumors.(breast tumor diagnosis)

2003 MAR 13 - (NewsRx.com & NewsRx.net) -- An ingenious advance in mammography may make it possible to detect cancer at a much earlier stage.

A research team has discovered that tumor cells give away their presence by scattering X-rays in a unique way, making them much easier to pinpoint among healthy cells.

In Britain, breast cancer affects 1 woman in 10 and is the biggest cause of cancer deaths among them. And like all cancers, early detection is crucial for reducing the chances of the tumor shedding cells and spawning secondary tumors elsewhere in the body.

But with today's cancer-screening systems, it's very hard to spot growths that are less than 10 mm wide, particularly in women younger than 45. That's because healthy breast tissue and tumors look very similar on a conventional mammogram. At that size, doctors are trying to find slightly less grey areas in fields of grey.

But physicist Robert Speller and a team at University College London are developing a new form of mammogram that can detect tumors only 4 mm wide, when they are too small to spawn secondaries and are easier to excise by surgery. His findings were described in the February 22, 2003 New Scientist (www.newscientist.com).

Conventional mammograms work by measuring how much a beam of X-rays is absorbed by the exposed tissue. But because healthy cells and cancer cells have a similar density, it is tough to tell them apart unless there is a big enough collection of tumor cells. And it is particularly hard to distinguish these cell types from one another in young women, whose tissue contains less fat than that of older women.

But Speller and his colleagues have discovered that tumor cells have a diffractive effect on X-rays - they ...