Research On Raman Spectra Of Serum In Nasopharyngeal Carcinoma

Objective: To research on the application value of laser Raman Spectra for serum screening and diagnosis in early nasopharyngeal carcinomaMethod: 17 cases of healthy volunteers and 29cases of newly diagnosed nasopharyngeal carcinoma by pathology were selected in our hospital from May 2009 to December 2009. Peripheral venous blood samples were taken from all subjects to tubes. All blood samples were centrifuged to remove blood cells; serous samples were obtained in the supernatant. InVia confocal Raman microscope was applied to test the samples. For each sample, we tested 5 spots for 5 Raman spectra. The average of 5 spectra in one sample represents the signal of Raman Spectra in one case. Then, Raman spectra of NPC patients group and healthy volunteers group were analyzed by statistical methods, including t-test, principal component analysis, discriminant analysis. Moreover, above statistical methods was applied to analyze Raman spectra of two sub-group of EBV-DNA negative and EBV-DNA positive in NPC patients.Results: The average of spectrum peaks in compared two groups is almost the same, while there is significant difference of frequency shift in major spectrum peaks between two groups. Intensity of common spectrum peaks I1445,I16510 and ratio of I1445╱I1651 are not statistically significant (related p values are: 0.08,0.51 and 0.41). Moreover, according to the discriminant analysis followed by principal component analysis, specificity or sensitivity of retrospective analysis between two groups is 100%, probability of error is zero. Compared to cross analysis, sensitivity is 100%, specificity is 93.1%(27/29), probability of error is 4.3%(2/46). Meanwhile, for the two sub-groups of EBV-DNA negative and EBV-DNA positive, sensitivity of retrospective analysis between two groups is 91.7%, specificity is 90.9%, probability of error is 8.7%(2/23). Compared to cross analysis, sensitivity is 41.7%(5/12), specificity is 45.5%(5/11), probability of error is 56.5%(13/23).Conclusion: Technology of laser Raman spectra is able to distinguish the serum in nasopharyngeal carcinoma from normal well, but incapable to detect the two sub-groups of EBV-DNA negative and EBV-DNA positive in nasopharyngeal carcinoma. Even though the results are encouraging, still, more cases are needed to confirm it.