Vibrational Spectroscopy and Cancer - Vibrational Spectroscopy for Tissue Analysis - page 62

Raman spectroscopy can achieve the diagnostic sensitivity of 93.5% and
specificity of 95.7% for precancer classification.
Jess et al. reported on application of Raman Spectroscopy for early detec-
tion of cervical neoplasia [61]. Raman microspectroscopy was applied to live
and fixed cultured cells and Raman spectra were acquired from primary
human keratinocytes (PHKs), PHK expressing the E7 gene of human papil-
lomavirus (HPV) 16 (PHK E7) and CaSki cells, an HPV16-containing cervical
carcinoma-derived cell line. Principal component analysis produced good
discrimination between the cell types, with sensitivities of up to 100% for the
comparison of fixed PHK and CaSki. The results demonstrated the ability of
Raman spectroscopy to discriminate between cell types representing differ-
ent stages of cervical neoplasia.
El-Tawal et al. compared smear cytology and FTIR spectroscopy in diag-
nosing cervical cancer [62]. A total of 800 cervical scrapings were taken by
cytobrush. After preparation stages, the samples were dried over an infra-
red transparent matrix. Beams of infrared light were directed at the dried
samples at frequencies of 4000 to 400 cm −1 . Data were compared with cytol-
ogy (gold standard). It was shown that FTIR spectroscopy can differentiate
normal from abnormal cervical cells in the samples examined. The sensitiv-
ity was 85%, specificity 91%, positive predictive value 19.5%, and negative
predictive value of 99.5%.

Epithelial Cancer
Some research groups have focused on epithelial tissues (Table 4.3). N. Stone
et al. for instance, applied NIR Raman spectroscopy for the classification of
epithelial cancers and precancers. The aim of their research was to evaluate
the use of the technique in interrogating epithelial tissue biochemistry and
distinguishing between normal and abnormal tissues. Tissues were selected
for clinical significance and included those that develop into carcinoma from
squamous, transitional, or columnar epithelial cells. Rigorous histopatho-
logical protocols were followed. The epithelial tissues were obtained from
larynx, tonsil, oesophagus, stomach, bladder, and prostate. Sensitivities and
specificities of up to 100% in separating the samples were obtained [63].

Table 4.3
Articles on Epithelial Tissues

Research
Group

Research
Method

Investigated Tissue
or Sample

Effectiveness of the
Technique

Reference
Number

Stone et al. Raman Epithelial tissue + 63

Stone et al. Raman Epithelial tissue + 64