Characterization of a Test for Invasive Breast Cancer Using X-ray Diffraction of Hair—Results of a Clinical Trial

OBJECTIVE To assess the performance of a test for breast cancer utilizing synchrotron x-ray diffraction analysis of scalp hair from women undergoing diagnostic radiology assessment. DESIGN AND SETTING A double-blinded clinical trial of women who attended diagnostic radiology clinics in Australia. PATIENTS 1796 women referred for diagnostic radiology, with no previous history of cancer. MAIN OUTCOME MEASURES Sensitivity, specificity and accuracy of the hair test analysis compared to the gold standard of imaging followed by biopsy where indicated. RESULTS The hair-based assay had an overall accuracy of >77% and a negative predictive value of 99%. For all women, the sensitivity of both mammography and X-ray diffraction alone was 64%, but when used together the sensitivity rose to 86%. The sensitivity of the hair test for women under the age of 70 was 74%. CONCLUSION In this large population trial the association between the presence of breast cancer and an altered hair fibre X-ray diffraction pattern previously reported has been confirmed. It appears that mammography and X-ray diffraction of hair detect different populations of breast cancers, and are synergistic when used together.