Recent research by Prof Veronica James, of the Australian National University, Canberra, and colleagues from Japan and America, suggest that testing a single hair fiber could be used to reliably screen for breast cancer in women. Hair from breast cancer patients has a different intermolecular structure to hair from healthy subjects.

A brief letter reported initial results of a research experiment on hair taken from women with breast cancer (James V, Kearsley J, Irving T, Amemiya Y, Cookson D. Using hair to screen for breast cancer. Nature 1999; Mar 4; 398(6722): 33-4). Prof James said: "Breast cancer screening is currently performed using mammography which, though effective, is a costly, uncomfortable and inconvenient test which limits its acceptability to many of the female population at risk of developing breast cancer."

The team investigated the structure of hair by measuring the way it scatters X-rays, a technique called X-ray diffraction. The technique relied on an intense source of X-rays, called synchrotron radiation. Both scalp and pubic hair were used, the latter being less likely to have undergone treatments, such as perming, that interfere with hair fiber structure. Hair taken from women diagnosed with breast cancer revealed rings of X-ray intensity in the diffraction pattern not seen in that of healthy subjects' hair. Breast cancer is associated with a faulty gene called BRCA1. All hair samples from women carrying a faulty BRCA1 gene showed the same structural anomaly in their hair fiber samples. Prof James said: "Our preliminary diffraction studies of hair give the strongest clues to date that breast cancer, or a predisposition to breast cancer, is strongly associated with structural changes in human hair samples.

Prof James said: "Breast cancer screening is currently performed using mammography which, though effective, is a costly, uncomfortable and inconvenient test which limits its acceptability to many of the female population at risk of developing breast cancer." If the technique is backed by larger trials, it could have "revolutionary implications" for detecting breast cancer. More extensive studies currently underway may take up to three years to complete.

This discovery has the potential to replace screening by mammography which is expensive and time consuming for both patients and doctors. These disadvantages would be removed by the new test using hair samples. However, if hair analysis is shown to be effective as a screening test it would still be important to give all women with a positive finding detailed counseling. Potentially a hair sample can be sent by a local family doctor to a central laboratory for testing. Results could be made available in just a few days.

Analysis of hair fiber by X-ray diffraction has been used since the late 1940s. It has helped us understand the chemical composition of hair and to identify hair production defects that occur in some diseases.