Conclusions: Colonoscopy prevented CRC in path_PMS2 carriers but not in the others. Our findings are consistent with colonoscopy surveillance blocking the adenoma-carcinoma pathway by removing identified adenomas which might otherwise become CRCs. However, in the other carriers most CRCs likely arised from dMMR cells in the crypts that have an increased mutation rate with increased stochastic chaotic probabilities for mutations. Therefore, this mechanism, that may be associated with no or only a short sojourn time of MSI tumours as adenomas, could explain the findings in our previous and current reports.
path_MMR:Pathogenic or likely pathogenic variant in one of the MMR genes (MLH1, MSH2, MSH6, or PMS2)
https://pubmed.ncbi.nlm.nih.gov/38741120/
Overall….colonoscopy works either by preventing some cancer, or where this is not biologically possible- by diagnosing cancer early.
Lynch Syndrome Ireland 