A new blood test has been developed by an international team of scientists which can detect the very early stage of breast cancer.

The test created by a team led by a British-based researcher, could be of particular benefit to younger women, for whom current mammography scans are less effective and it also promises to be useful in identifying prostate cancer, ovarian cancer and melanoma.

The technique does this by measuring the numerous proteins to find a characteristic cancer fingerprint and in a trial with 345 women the blood test picked up 95% of cancers, and missed 5% making it much more sensitive than existing tests.

When cancer was not present, the test again correctly identified this 95% of the time and incorrectly said there was a tumour present 5% of the time.

Breast cancer remains the most common cancer for women worldwide, with 1.1 million new cases and an estimated 300,000-400,000 deaths occurring each year.

Early detection and effective therapy are critical to the survival rate and at present a diagnosis relies on triple testing - breast examination, imaging with mammography and ultrasonography, and a biopsy.

Accurate blood testing could reduce the need for open biopsy, say the scientists.

According to the researchers the new blood test which measures the blood markers of cancer has been shown to be 200 to 1,000 times more sensitive than existing tests.

The blood test detects very small changes in concentrations of proteins in the blood and while some of the proteins are specific for breast tissue, others fluctuate with many types of cancers and are markers of inflammation and new blood vessel growth in response to the tumour.

Professor Jasminka Godovac-Zimmermann, of University College London, who led the research group, says the pilot studies demonstrated that by using blood samples, breast cancer and several other types of epithelial cancers can be detected with much more sensitivity and specificity.

The professor says this may mean less intrusive, safer and much less expensive approaches for the early diagnosis of cancer, and for distinguishing malignant and benign cancers, and for monitoring cancer therapy.

The team included scientists from the University of Pennsylvania, the University of Pittsburgh and BioTraces Inc, a company based in Herndon, Virginia.

They are now exploring how many, and which combinations of protein markers would be needed to screen for several cancers simultaneously in one blood test.

They say further research involving an independent group of patients and healthy volunteers is now needed to validate these results, and to find out if the test is equally accurate for diagnosing early breast cancer as well as advanced disease.

The study is published in the American Chemical Society’s Journal of Proteome Research reports.