Fig. 1

Matched adenoma-carcinoma samples. a Macroscopic view of a pedunculated polyp in the colon (sample AC20). b Microscopic view of a bisected polypectomy specimen containing both adenoma and carcinoma components seen at low magnification. Hematoxylin and eosin (H&E) staining. Scale bar 1000 μm. The arrow points to a higher magnification (× 5) of the area marked where normal colon, remnant adenoma, and early carcinoma components are visible. Scale bar 200 μm. For DNA analyses, adenomatous and carcinomatous components were separately scratched from the same sample and sequenced with a colorectal cancer (CRC)-specific panel. c Experimental layout of our study, indicating assays used, the output we can expect, and why we chose each assay. The numbers of samples employed for each assay are in brackets. IHC, Immunohistochemistry; FISH, fluorescent in situ hybridization; CHP, cancer hot spot