Label-free detection of prostate cancer and benign prostatic hyperplasia based on SERS spectroscopy of Plasma

In this work, Surface-enhanced Raman spectroscopy (SERS) involving blood plasma was investigated; the objective was to determine whether this approach could distinguish prostate cancer with benign prostatic hyperplasia. The experimental samples were prepared by blood plasma mixed with the silver colloid over an aluminum plate substrate. A total of 14 SERS spectra for prostate cancer (PCa) and 14 spectra for benign prostatic hyperplasia (BPH) were successfully gathered from patients who came from Fujian Provincial Hospital. Difference spectrum analysis combined with the assignment of Raman bands indicated that there were subtle but distinct changes between prostate cancer (PCa) and benign prostatic hyperplasia (BPH), which could be related to the level of prostate specific antigen (PSA); because it has been reported that the level of PSA is increased in men who have prostate cancer compared with those with benign prostatic hyperplasia (BPH). To further make clear the difference of Prostate cancer (PCa) and benign prostatic hyperplasia (BPH), the spectral data was combined with multivariate analysis processes. Principal component analysis (PCA), as a spectral dimensionality reduction approach, and in conjunction with linear discriminant analysis (LDA) were employed to identify the samples, to build diagnostic algorithms. The leave-one-out cross-validation method was used to validate the diagnostic algorithms; the result showed that a sensitivity of 95.8% and a specificity of 100.0% which indicated can significantly differentiate PCa and BPH groups. In addition, we further verify the validity of the diagnosis algorithm based on PCA-LDA diagnosis algorithm by using receiver operating characteristic (ROC) curves. The results of experiment study suggest that SERS combined with PCA-LDA algorithms has great potential for clinical screening of benign prostate hyperplasia and prostate cancer.