A study of colorectal cancer patients’ hair medulla by synchrotron radiation infrared microspectroscopy

Abstract

Colorectal cancer seriously threatens life and health of human beings due to its high morbidity and mortality. At present, colonoscopy and biopsy are “the gold standard” for diagnosing colorectal cancer, however, they have several limitations. Since early diagnosis is very important for colorectal cancer treatment, it is of great urgency to develop new methods for detecting colorectal cancer early. As a place occuring metabolism, hair is closely related with human health status and genetic characteristics, etc. Synchrotron radiation infrared (SR-IR) microspectroscopy has the ability to gain IR spectra of hair medulla accurately. In this study, we applied SR-IR microspectroscopy to comparison of hair medulla from colorectal cancer patients and healthy persons. Peak-area ratios indicated that colorectal cancer might cause the changes of proteins, lipids and nucleic acids in hair medulla. Based on the above peak-area ratios, discriminant analysis obtained the sensitivity as 74.6%, the specificity as 83.8%, the positive predictive value as 88.7% and the accuracy as 78.0%. Principal component analysis (PCA) further displayed that colorectal cancer might alter proteins and nucleic acids in hair medulla significantly. In sum, the above results showed potential application value of hair medulla’s IR spectra in early diagnosis of colorectal cancer.