The research the investigators plan to undertake involves the use of a paper substrate with a gold metamaterial on top or a plastic substrate with gold metamaterial on top in physical contact with paper. The metamaterial has an absorption peak within the terahertz frequency range to be investigated (0.75 - 1.1THz). The serum samples will be soaked into the paper fibres which will shift the absorption peak within the terahertz frequency range dependent on the concentration of tumour markers present in the sample. The serum samples will be surplus from samples tested for CEA, LDH, CA-125, CA 19-9, CA 15-3, total-hCG and AFP at the Durham and Darlington NHS Fondation Trust. The samples will be anonymised with the exception of which tumour marker they were tested for and the level measured.~There will be two stages to this research project the initial stage requires 15 samples per proposed marker including 15 samples (across all markers) for negative results. This will be used to identify suitable markers to consider for the second stage. Where 50 to 90 samples of each qualifying marker will be tested dependent on the number required for statistical confidence in stage two with 10 to 18 negative samples required for each qualifying marker, again dependent on the statistical requirements for each marker.
The research the investigators plan to undertake involves the use of a metamaterial at terahertz frequencies. Serum samples will be tested using the metamaterial to determine if this method can be used to measure the concentration of tumour markers present in the sample. Patients who have been tested for CEA, LDH, CA-125, CA 19-9, CA 15-3, total-hCG and AFP will be used for both the positive and negative samples.