An Investigation into FTIR Spectroscopy as a Biodiagnostic Tool for Cervical Cancer BAYDEN R. WOOD,’ MICHAEL A. QUINN,’ FRANK R. BURDEN,’ and DONALD McNAUGHTON’* ’ Department of Chemistry, Monash University, Wellington Road, Clayton, Victoria, 31 68, Australia, and ’Department of Obstetrics and Gynaecology, University of Melbourne, Grattan Street, Parkville, Victoria, 3052, Australia SYNOPSIS Fourier-transform infrared (FTIR) microspectroscopy, combined with Principal Compo- nent Analysis (PCA) , was applied in the study of exfoliated cervical cells from 272 pa- tients. Six spectra were recorded for each patient, and these were visually sorted into two types (type 1 and type 2) , based on their profiles. Spectra designated type 1 exhibited a profile characteristic of normal epithelial cells, with intense glycogen bands at 1022 cm-’ and 1150 cm-’, and a pronounced symmetric phosphate stretch at 1078 cm-’ . Spectra designated type 2 exhibited features suggestive of dysplastic or malignant transformation, with pronounced symmetric and asymmetric phosphate modes and a reduction in glyco- gen-band intensity. Of the 272 patients, 68.6% of samples exhibited only type 1 profiles for all six recorded spectra, 29.4% of samples yielded at least one type 2 spectrum in any of the six recorded spectra and 2% of samples were inconclusive. Of the 68.6%, 86% were diagnosed normal by Pap smear with no follow up biopsy ordered, 7% were diagnosed abnormal by biopsy, 5% normal by biopsy and 2% were still inconclusive. For the remaining 29.4% of classified samples, 71% had shown an abnormal Pap result. These 71% were subsequently biopsied, and 87% were confirmed abnormal. The association of type 2 spectra and abnormality was further corroborated by spectra of cultured malignant cells from the HeLa cell line that displayed a profile similar to type 2 spectra in the 1300-950 cm-’ region. PCA de- composition using a reduced data matrix resulted in a score plot that showed general separation of the visually categorised spectra. This study demonstrates the potential of automated FTIR cervical screening technology in the clinical environment. 0 1996 John Wiley & Sons, Inc. I NTRO DUCT10 N Cancer of the cervix is a common malignant tu- mour of the female genital tract. The current screening method for preinvasive human cervical intraepithelial neoplasia ( CIN ) is the Papanico- laou smear test, commonly known as the “Pap smear.” Despite its widespread practical accep- tance the Papanicolaou test gives up to 20% false negative results.’ An alternative technique that is nonsubjective, easy to perform, relatively inexpen- * To whom correspondence should be addressed. Biospectroscopy, Vol. 2,143-153 (1996) 0 1996 John Wiley & Sons, Inc. CCC 1075-4261/96/030143-11 sive, and accurate in diagnosis is now clearly needed. Changes in the tissue biochemistry must pre- cede any morphological or symptomatic manifes- tation associated with a diseased state,2 so spectro- scopic diagnosis is a logical alternative for the early detection of disease. Recently Ge et al.3have inves- tigated the potential of near-infrared spectroscopy in this field, while Wong et al.4,5 have applied mid- infrared spectroscopy to the analysis of exfoliated cervical cells and shown it to be a promising tool for screening. Wong et al.4*5 found that there were distinct and reproducible differences in the IR spectra of malignant and normal cervical epithelial cells and that there was evidence for differences be- tween normal and dysplastic (precancerous ) cells. 143