Research On Surface Enhanced Raman Spectroscopy In Serum Detection Of Gastrointestinal Cancer

ObjectiveTo investigate the clinical value of surface-enhanced Raman spectroscopy in the diagnosis of gastric cancer and colorectal cancer.Furthermore,the feasibility of surface-enhanced Raman spectroscopy in discriminating gastrointestinal cancer at different TNM stages is evaluated.MethodWith the silver nanoparticles as enhancement substrate,laser confocal microscope detection of InVia+Plus Raman spectrometer was used to examine the serum of pathologically confirmed gastric cancer(63 cases),gastric precursor lesions(45 cases),colorectal cancer(95 cases),colorectal precursor lesions(55 cases),and healthy(50 cases).Using the one-way ANOVA,Student's t test,principal component analysis(PCA),linear discriminant analysis(LDA)multivariate statistical analysis techniques on the Raman spectra data statistics processing,and use receiver operating characteristic curve(ROC)sample area to evaluate the diagnostic efficiency.Results1.Morphology and spectral peaks of serum surface enhanced Raman spectra were similar in gastric cancer group,precursor lesions group and normal control group.The typical spectral peaks of the three groups were located at around 629,725,815,961,1004,1099,1133,1220,1273,1328,1446,1589 and 1657cm-1 Raman shift,while there were significant differences in peak intensity among the three groups.Raman intensity located at 725,1099,1133 and 1589 cm-1 was significantly stronger in the spectra of the gastric cancer group than those in the normal control group(P<0.05).Raman intensity of the gastric precursor lesions group and the gastric cancer group was significantly weaker than that of the normal control group at around 1004,1328,1446,1657 cm-1(P<0.05).Compared with the normal control group,there was a characteristic peak at 815cm-1 in the precursor lesions group and the gastric cancer group,and the differences were statistically significant among these three groups(P<0.05).The sensitivity,specificity and accuracy of SERS technique combined with PCA-LDA analysis in the diagnosis of gastric cancer were 96.8,78%and 88.5%,respectively.The area under the curve was 0.927.2.The intensity of serum SERS spectrum in TNM stage III-IV group was significantly stronger than that in stage ??? group at 1133,1446 and 1589 cm-1,while was weaker than that in stage I?II group at 1004 cm-1(P<0.05).The sensitivity,specificity and accuracy of SERS technique combined with PCA-LDA analysis in discriminating stage ??? from stage ??? of gastric cancer was 97.5,73.9%and 88.9%,respectively.The area under the curve was 0.857.3.The typical serum SERS spectral peaks of the colorectal cancer group and precursor lesions were located at around 629,725,815,889,961,1099,1142,1218,1273,1331,1450,1497,1589 and 1657cm-1 Raman shift,while there were significant differences in peak intensity among the three groups.Raman intensity located at 1099,1218,1450 and 1589 cm-1 was significantly stronger in the spectra of the colorectal precursor group than those in the colorectal cancer group as well as normal control group(P<0.O5).Compared with normal control group and precursor lesions group,there were three characteristic peaks at 815,1273 and 1497cm-1 in the colorectal cancer group.The sensitivity,specificity and accuracy of SERS technique combined with PCA-LDA analysis in the diagnosis of colorectal cancer were 96.8%and 96.5%,respectively.The area under the ROC curve was 0.997.4.The intensity of serum SERS spectrum in TNM stage ??? group was significantly stronger than that in stage ?-? group at 1218 cm-1,while was weaker than that in stage ??? group at 1331 and 1657cm-1(P<0.05).The sensitivity,specificity and accuracy of SERS technique combined with PCA-LDA analysis in discriminating stage I?II from stage III~IV of colorectal cancer was 75.4%,81.6%and 77.9%,respectively.The area under the curve was 0.860.ConclusionSerum surface-enhanced Raman spectroscopy can effectively identify gastrointestinal cancer patients and healthy people,and can effectively distinguish gastric cancer or colorectal cancer at different stages.It is expected to become a nondestructive,efficient and accurate early screening method for gastric cancer and colorectal cancer.It may be a nondestructive,efficient and accurate early screening method for gastric cancer and colorectal cancer,and has a great potential to discriminate different stages of gastrointestinal cancer rapidly and simply.