Vibrational Spectroscopy and Cancer - Vibrational Spectroscopy for Tissue Analysis - page 67

the highest for fibroadenoma and carcinoma (E). The 1680 cm −1 /1657 cm −1
absorbance ratio decreased significantly in the order of normal, hyperpla-
sia, fibroadenoma and carcinoma (F). The 1651 cm −1 /1545 cm −1 absorbance
ratio increased slightly for fibroadenoma and carcinoma (G). The bands at
1204 cm −1 and 1278 cm −1 , assigned to the vibrational modes of the collagen,
did not appear in the original spectra as the resolved peaks and were
distinctly stronger for the carcinoma tissues (H). The 1657 cm −1 /1204 cm −1
and 1657 cm −1 /1278 cm −1 absorbance ratios, both yielding information on the
relative content of collagen increased in the order ofnormal, hyperplasia,
carcinoma, and fibroadenoma [74].
N. J. Kline and P. J. Treado reported on chemical imaging of breast tissue
using Raman spectroscopy. Raman chemical imaging of lipid and protein
distribution in breast was performed without the use of invasive contrast
agents. Instead, tissue component discrimination was based on the unique
vibrational spectra intrinsic to lipids and proteins. It was suggested that
visualization of breast tissue components is an essential step in the develop-
ment of a quantitative Raman 'optical biopsy' technique suitable for the non-
invasive detection and classification of breast cancer [75].
K. E. Shafer-Peltier et al. reported on a Raman spectroscopic model of
human breast tissue and its implications for breast cancer diagnosis in vivo.
They believe that Raman spectroscopy has the potential to provide real-time,
in situ diagnosis breast cancer during needle biopsy or surgery via an opti-
cal fibre probe. To understand the relationship between the Raman spec-
trum of a sample of breast tissue and its disease state, near-infrared Raman
spectroscopic images of human breast tissue were acquired using a confo-
cal microscope. These images were then compared with phase contrast and
hematoxylin- and eosin-stained images to develop a chemical/morphologi-
cal model of breast tissue Raman spectra. The model explained the spectral
features of a range of normal and diseased breast tissue samples, including
breast cancer, and it also could be used to relate the Raman spectrum of a
breast tissue sample to diagnostic parameters used by pathologists [76].
In addition to FTIR and Raman spectroscopy, some other techniques such
as nuclear magnetic resonance (NMR) have been employed for research in
the field of cancer. S. M. Ronen et al. studied the metabolism of the lipids of
the human breast cancer using the 31 P NMR technique [77].
C. J. Frank et al. compared Raman spectra of histologically normal human
breast biopsy samples to those exhibiting infiltrating ductal carcinoma (IDC)
or fibrocystic change. Experiments at 785 nm with charge-coupled device
(CCD) detectors reduced fluorescence interference. Sample-to-sample and
patient-to-patient variation for normal specimens were less than 5% for the
ratios of major Raman bands. The Raman spectra changed dramatically
in diseased specimens, with much weaker lipid bands being evident. The
spectra of IDC samples were similar to that of human collagen. Differences
between benign (fibrocystic) and malignant (IDC) lesions were smaller than
those between normal and IDC specimens, but were still reproducible [78].