Towards non-invasive, high-throughput lung cancer screening: Biomarker detection in saliva via surface-enhanced Raman spectroscopy

Bronchial carcinoma is the cancer type with the highest mortality worldwide. This is mainly caused by late diagnosis of the disease as mostly only early stages are curable. Common detection methods are not suitable for pre-screening of populations or high-risk patients like smokers. Although there have been some promising approaches, until now no highly sensitive and specific diagnostic tests suitable for high-throughput screening have been developed for clinical use. One candidate group of relevant biomarkers in this context are sialic acids (SA) which play an important role during tumor transformation and progression. Recently, by employing a combination of surface-enhanced Raman scattering spectroscopy (SERS) and citrate-silver-nanoparticles (citrate-Ag NP) with the ability to bind to SA, the detection of breast and ovarian cancer in saliva was successfully proven by our cooperation partner Prof. Hugo Navarro Contreras. In this proof of principle study, we want to evaluate SERS as a fast and non-invasive method for screening and early detection of lung cancer. Therefore, in the first approach, a) citrate-Ag NP and b) different SERS substrates will be used to detect lung cancer specific patterns and SA levels in saliva. In a second approach the saliva will be analysed by SERS to identify a specific spectral fingerprint related to lung cancer or high-risk patients.