The BBC's Fergus Walsh on the hair test

The study showed that the hair of patients with breast cancer has a different intermolecular structure to the hair of healthy people.

X-rays of the cancer patients' hair, conducted using powerful diffraction equipment, showed the hair had a thick ring around it.

Cancer specialists say it is unlikely any diagnostic test will be developed, but they say the research could offer pointers to future treatments for breast cancer.

Mutated gene

The researchers conducted four studies. In the first on cancer patients, all 23 turned out to have hair which had a different structure from normal, healthy hair.

The second test involved people who were not thought to have cancer. Twenty-four of the twenty-eight had normal hair.

In another test involving people who tested positive for a mutated gene linked to a family history of breast cancer, the hair of three out of five people studied had the full change associated with cancer.

The hair of the other two people showed a partial change.

The scientists say they prefer to use pubic hair as it is less likely to have been permed or coloured.

Hair which has been chemically altered within a three-month period can influence test results.

The scientists, from the University of New South Wales, say they do not know why the hair changes its molecular structure.

But they believe it may be linked to the fat layers in hair cell membranes.

In a letter to Nature magazine, they write: "Because our results are so consistent, we propose that such hair analyses may be used as a simple, non-invasive screening method for breast cancer."

They say more research is needed into the sensitivity and specificity of the test.

Eventually, they believe, a test could be developed which involved analysing just one pubic hair.

Breast cancer is said to affect one in 12 women in the West and accounts for 20% of all female cancers.

Scepticism

But cancer specialists are sceptical about whether a hair test can be developed.

The Cancer Research Campaign (CRC) said more research was needed to back the researchers' findings.

Professor Gordon McVie, director general of the CRC, said: "There is no way there will be a screening test within the next 15 to 20 years."

He said the researchers had not done any control tests, for example, comparing how accurate the hair samples were for women with benign tumours.

Also, the diffraction machines used were very powerful and very expensive and many countries did not have even one of them.

However, he added that the changes in the molecular structure of the hair was "intriguing" and, if caused by a unique protein, could provide a target for chemists looking for treatments for breast cancer.