HPLC-LIF for early detection of oral cancer

At present, the diagnosis of many cancers relies on the subjective interpretation of morphological changes in biopsy samples. This usually provides only late diagnosis. Early detection, which can provide more successful therapy, is expected to be possible by identification of tumour markers in physiological samples. Immunoassay used at present for this purpose has several drawbacks. It is applicable only for known markers, can usually detect only one marker at a time, and may also fail to detect a marker when there exist conditions, which may mask or prevent the interaction between antigen and the antibody. We have developed a high performance liquid chromatography-laser induced fluorescence (HPLC-LIF) technique to detect and record simultaneously spectra and chromatograms of physiological samples, which will enable the detection of multiple 'markers' in a single physiological sample in a short time. Samples of saliva and serum from normal and oral cancer subjects have been studied with the set up. The present studies show that body fluids like saliva and serum of normal, pre-malignant and malignant subjects have substantially different protein profiles. By simultaneous recording of the chromatographic peaks and corresponding fluorescence spectra, it is possible to carry out unambiguous discrimination between normal, pre-malignant and malignant cases even when markers are present in femto/subfemtomole quantities, which should assist in early diagnosis of neoplasia.