Nasopharyngeal cancer screening and immunotherapy efficacy evaluation based on plasma separation combined with label-free SERS technology

Background: In recent years, significant progress has been made in the treatment of nasopharyngeal carcinoma (NPC). The application of immunotherapy, especially the use of Programmed Cell Death Protein 1 inhibitors, has demonstrated excellent therapeutic effects. However, inconsistent immunotherapy outcomes due to individual differences in patients remain a major challenge, maki ng the search for specific biomarkers to screen for the population who may benefit from immunotherapy a priority. Surface-enhanced Raman spectroscopy (SERS) has shown great potential as a highly sensitive and specific optical analytical tool for identifying and monitoring tumor-related markers in NPC. Results: In this study, plasma samples from Nasopharyngeal cancer patients before and after immunotherapy, along with those from healthy volunteers, were tested using label-free SERS combined with plasmapheresis. Especially, the components with varying molecular weight sizes were analyzed via the separation process, thereby preventing the potential loss of diagnostic information that could result from competitive adsorption. Subsequently, a robust machine learning algorithm based on principal component analysis and linear discriminant analysis (PCA-LDA) was used to extract features from plasma SERS data and establish an effective discriminant model. The results showed that in the upper plasma layer, the most optimal discrimination was found between normal patients and those post-treatment, with sensitivity and specificity of 88.5 % and 92.3 %, respectively. In the lower plasma layer, the most optimal discrimination was found between the pre-treatment and post-treatment patients, with sensitivity and specificity of 84.6 % and 80.8 %, respectively. Significance and novelty: Plasmapheresis can reveal latent diagnostic information in the plasma and holds promise for treating NPC, the screening of the population who may benefit from immunotherapy, and the postoperative evaluation of immunotherapy. Further exploration of the feasibility of using SERS to detect tumor markers in the population who may benefit from immunotherapy a priority. Surface-enhanced Raman spectroscopy (SERS) has shown great potential as a highly sensitive and specific optical analytical tool for identifying and monitoring tumor-related markers in NPC. Results: In this study, plasma samples from Nasopharyngeal cancer patients before and after immunotherapy, along with those from healthy volunteers, were tested using label-free SERS combined with plasmapheresis. Especially, the components with varying molecular weight sizes were analyzed via the separation process, thereby preventing the potential loss of diagnostic information that could result from competitive adsorption. Subsequently, a robust machine learning algorithm based on principal component analysis and linear discriminant analysis (PCA-LDA) was used to extract features from plasma SERS data and establish an effective discriminant model. The results showed that in the upper plasma layer, the most optimal discrimination was found between normal patients and those post-treatment, with sensitivity and specificity of 88.5 % and 92.3 %, respectively. In the lower plasma layer, the most optimal discrimination was found between the pre-treatment and post-treatment patients, with sensitivity and specificity of 84.6 % and 80.8 %, respectively. Significance and novelty: Plasmapheresis can reveal latent diagnostic information in the plasma and holds promise for treating NPC, the screening of the population who may benefit from immunotherapy, and the postoperative evaluation of immunotherapy. Further exploration of the feasibility of using SERS to detect tumor markers in the population who may benefit from immunotherapy for NPC will help improve the therapeutic efficacy, optimize clinical practice, and promote the development of individualized treatment strategies.