Scientists have developed a simple blood test that is capable of detecting breast cancer in women before it can be detected by standard screening methods.

Normal breast screening checks using x-rays - only detect a tumour once it is three of four times bigger, by which time it may have started to spread beyond the breast.

The new test, developed by a Norwegian company called Diagenic ASA, detects raised level of chemical markers for cancer picked up as blood flows through a tumour. It is expected to pick up a cancer the size of a small seed before a woman has developed any symptoms, reports telegraph.co.uk.

"This test will be particularly useful for younger women who are at risk of developing breast cancer," said Dr James Mackay an oncologist and researcher at University College London.