Advances in surface-enhanced Raman spectroscopy for cancer diagnosis and staging

Surface-enhanced Raman spectroscopy (SERS) is rapidly emerging as a bioanalytical tool for cancer diagnosis and therapy. The SERS-based molecular diagnostics have progressed from proof-of-concept studies towards analysis in animal models as well as for in vitro clinical diagnostics in the last decade. Recently, SERS has also been implemented in screening, diagnosis, and staging of clinical cancer samples. Moreover, in vivo SERS imaging has been implemented for mapping the extent of tumor growth and metastasis; SERS nanoparticles have also enabled image-guided therapies strongly indicating SERS technology can significantly complement the practice of oncology. Despite the progress, widespread clinical translation of SERS nanoparticles is still challenging. Current SERS strategies in diagnostic oncology require further development and standardization to progress from bench-top to point-of-care applications. The present review critically analyzes the current state of the art about various strategies for SERS-based cancer detection and staging from cellular metabolites, exosomes, circulating tumor cells, extracellular fluids, and cancer cells.