INFRARED-SPECTROSCOPY OF NORMAL AND ABNORMAL CERVICAL SMEARS - EVALUATION BY PRINCIPAL COMPONENT ANALYSIS

Fourier-transform infrared (FT-IR) spectra of malignant and dysplastic cervical scrapings were abnormal, as first described in our study of a limited number of samples, where the spectra were evaluated by visua l inspection and peak intensity ratios. We have expanded our study to evaluate more cervical conditions, and to analyze the spectra by a che mometric approach (principal component analysis [PCA]). Cervical sampl es from 436 females were evaluated by FT-IR and Papanicolaou testing; 40/436 spectra were nonanalyzable. The remaining were as follows: norm al, 174; malignant, 19; dysplasia, 8; atypia, 113; atrophy, 19; inflam matory, 47; bloody smear, 12; hypocellular, 4. PCA analysis followed b y chi(2) test revealed that statistically significant frequencies of b eing predicted malignant by FT-IR were associated with samples diagnos ed as malignant (P < 0.0001), and also those diagnosed as ''atrophy'' (P < 0.001), ''atypical with bloody smear'' (P < 0.05), ''atypical wit h atrophic pattern'' (P < 0.05), and ''dysplasia'' (P < 0.05). Based o n these findings, for the diagnosis of cervical cancer by FT-IR, as de fined here, the sensitivity is 79%, the specificity is 77%, the positi ve predictive value is 15%, and the negative predictive value is 98.6% . Our findings (a) demonstrate the application of a chemometric approa ch to the study of cervical FT-LR spectra; (b) assess its potential di agnostic role; (c) suggest that atrophic and neoplastic samples share structural features; and (d) suggest that blood may interfere with suc h spectroscopic evaluation. These findings warrant further evaluation of FT-IR spectroscopy in cervical and other malignancies. (C) 1997 Aca demic Press.