The aim of this case study was to explore the relationship between porphyrins and colon adenocarcinoma, and to examine the potential of porphyrin-induced fluorescence for the diagnosis of colon cancer. Further studies were carried on 8 cases ex vivo colon adenocarcinoma samples which exceptionally exhibited 635 nm fluorescence emission under 405 nm excitation. The time-resolved fluorescence spectra at 635 nm emission under 405 nm excitation were also measured and two-exponential decay fitting was performed to determine the fluorescence lifetime at 635 nm emission. Significant difference was observed between the spectra of normal and cancer tissues, which included an emission peak at 635 nm under the excitation wavelengths of 405 nm. There was also a significant difference between the fluorescence lifetimes of 635 nm emission of the normal tissue and cancer tissue (P<0.05). These results demonstrate that the spectroscopic analysis method allows a selective detection of adenocarcinoma tissues. This spectral profile and lifetime of the red fluorescence resemble that of porphyrins, which suggests that porphyrin fluorescence may be a useful biomarker for characterizing colon cancers of certain patient populations.

Date Published: 19 March 2013
PDF: 7 pages
Proc. SPIE 8577, Optical Biopsy XI, 857703 (19 March 2013); doi: 10.1117/12.2002224

Published in SPIE Proceedings Vol. 8577:
Optical Biopsy XI
Robert R. Alfano; Stavros G. Demos, Editor(s)