Patient characteristics of training and test studies.

1Colorectal lesions are divided regarding their location into ‘Distal’: descending, sigmoid, left flexure, rectum and ‘Proximal’: cecum, ascending, right flexure, transverse. 2Non-colorectal Cancer include bladder, breast, liver, lung, prostate and pancreatic cancers. 3Non-cancerous Diseases include gastritis, hypertension, type II diabetes, liver disease, rheumatoid and non- rheumatoid arthritis, cholycystitis, cystitis, chronic heart disease, esophagitis, IBD, pancreatitis, chronic renal failure, respiratory infection. 4Total sample numbers can be higher than the sum of all subgroups when sample annotations are missing, for some patient samples SEPT9 methylation measurement was incomplete. 5Median patient age at time of sample collection in years.