Near‐infrared Raman spectroscopy for the classification of epithelial pre‐cancers and cancers

Abstract

The use of near-infrared Raman spectroscopy to interrogate epithelial tissue biochemistry and hence distinguish between normal and abnormal tissues was investigated. Six different epithelial tissues from the larynx, tonsil, oesophagus, stomach, bladder and prostate were measured. Spectral diagnostic models were constructed using multivariate statistical analysis of the spectra to classify samples of epithelial cancers and pre-cancers. Tissues were selected for clinical significance and to include those which develop into carcinoma from squamous, transitional or columnar epithelial cells. Rigorous histopathological protocols were followed and mixed pathology tissue samples were discarded from the study. Principal component fed linear discriminant models demonstrated excellent group separation, when tested by crossvalidation. Larynx samples, with squamous epithelial tissue, were separated into three distinct groups with sensitivities ranging from 86 to 90% and specificities from 87 to 95%. Bladder specimens, containing transitional epithelial tissue, were separated into five distinct groups with sensitivities of between 78 and 98% and specificities between 96 and 99%. Oesophagus tissue can contain both squamous and columnar cell carcinomas. A three group model discriminated the columnar cell pathological groups with sensitivities of 84-97% and specificities of 93-99%, and an eight group model combining both columnar and squamous tissues in the oesophagus was able to discriminate pathologies with sensitivities of 73-100% and specificities of 92-100%. It is likely that any overlap between pathology group predictions will have been due to a combination of the difficulty in histologically distinguishing between pre-cancerous states and the fact that there is no biochemical boundary from one pathological group to the next, i.e. there is believed to be a continuum of progression from the normal to the diseased state.

Raman spectroscopy can differentiate malignant tumors from normal breast tissue and detect early neoplastic changes in a mouse model

“…8,11,[34][35][36][37][38][39][40][41][42][43][44] Our data is confirmatory, and, in addition, demonstrates changes in the tumor bed, which probably represent the detection of chemical signs of preneoplastic changes.…”

The use of Raman spectroscopy to identify and grade prostatic adenocarcinoma in vitro

“…Figure 3 shows the mean spectra recorded from BPH and all prostate cancers studied. Where visual differences in the peak heights of the two spectra were noted, the relevant literature was consulted for information as to the nature of these peaks (Hartman et al, 1973;Manoharan et al, 1995;Boustany et al, 1996;Mahadevan-Jansen, 1996;Manfait et al, 2000;Stone et al, 2002). Although the biochemical designations of many peaks remain uncertain, the differences between the two mean spectra suggest that prostate cancer has increased levels of nucleic acids and reduced levels of glycogen, when compared to BPH.…”

High sensitivity non‐invasive detection of calcifications deep inside biological tissue using Transmission Raman Spectroscopy

“…Raman spectroscopy has been proposed as a non-invasive and label free analytical method with a very consistent and prolific track record of in-vitro biomedical applications [22][23][24] for histopathological screening [25][26][27][28][29] as well as probing of lymph node pathology using fibre probes [30][31][32].…”