Protein Signature Based Screening of Colorectal Adenomas and Cancer

ProScreen Study I is a prospective, exploratory cohort study conducted at Skåne University Hospital, Sweden. The study aims to identify blood-based protein profiles associated with advanced colorectal adenomas and colorectal cancer, with the long-term goal of contributing to the development of improved methods for colorectal cancer prevention and early detection. Patients scheduled for colonoscopy, as well as patients with confirmed colorectal lesions, will be invited to participate. After providing informed consent, participants will provide a blood sample specifically for research purposes. Blood will be collected using the Capitainer quantitative dried blood spot (qDBS) method, which enables standardized sampling of a small volume of blood. The research sampling is performed in addition to routine clinical care and does not alter the participants' diagnostic procedures or treatment. The dried blood spot samples will be analyzed using proximity extension assay (PEA) technology and the Olink Explore HT platform to measure a large number of proteins simultaneously. Protein abundance will be compared across the study groups to identify proteins and combinations of proteins associated with advanced colorectal adenomas and colorectal cancer. Statistical analyses will include comparisons of protein levels between groups and the development of multivariable predictive models using penalized regression methods, including glmnet. The diagnostic performance of candidate protein signatures will be evaluated using receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC), together with estimates of sensitivity and specificity where appropriate. An interim analysis is planned after the first 100 participants have been evaluated. The findings will be used to assess the feasibility of the analytical approach and inform subsequent development and validation within the broader ProScreen research programme. This study involves no experimental treatment. Its purpose is to investigate associations between blood protein profiles and colorectal disease status. The findings may provide a basis for future studies evaluating blood-based tests for the detection of advanced precancerous lesions and colorectal cancer.