Colorectal carcinogenesis in the Lynch syndromes and familial adenomatous polyposis: trigger events and downstream consequences.

Carcinogenesis encompasses processes that lead to increased mutation rates, enhanced cellular division (tumour growth), and invasive growth. Colorectal cancer (CRC) carcinogenesis in carriers of pathogenic APC (path_APC) and pathogenic mismatch repair gene (path_MMR) variants is initiated by a second hit affecting the corresponding wild-type allele. In path_APC carriers, second hits result in the development of multiple adenomas, with CRC typically emerging after an additional 20 years.

Adenomas from individuals with pathogenic biallelic variants in the MUTYH and NTHL1 genes demonstrate base excision repair tumour mutational signature profiles similar to colorectal cancers, expanding potential diagnostic and variant classification applications.

Background: Colorectal cancers (CRCs) from people with biallelic germline likely pathogenic/pathogenic variants in MUTYH or NTHL1 exhibit specific single base substitution (SBS) mutational signatures, namely combined SBS18 and SBS36 (SBS18+SBS36), and SBS30, respectively. The aim was to determine if adenomas from biallelic cases demonstrated these mutational signatures at diagnostic levels.

Methods: Whole-exome sequencing of FFPE tissue and matched blood-derived DNA was performed on 9 adenomas and 15 CRCs from 13 biallelic MUTYH cases, on 7 adenomas and 2 CRCs from 5 biallelic NTHL1 cases and on 27 adenomas and 26 CRCs from 46 non-hereditary (sporadic) participants.

Future of Acute Severe Ulcerative Colitis-A Narrative Review.

While corticosteroids have led to significant reduction in ASUC mortality over the last few decades, they are associated with significant side effects and up to 30% of patients have steroid refractory ASUC, which means we require safer and better therapies for patients with ASUC. Several salvage therapies have been proposed in guidelines; however, we lack high quality head-to-head randomised controlled trials to assess effectiveness and safety of these agents. Furthermore, the role of newer novel agents in ASUC management is unclear.

Fibrin film on clots is increased by haematocrit but reduced by inflammation: implications for platelets and fibrinolysis.

Background: Blood clot formation, triggered by vascular injury, is crucial for haemostasis and thrombosis. Blood clots are composed mainly of fibrin fibres, platelets and red blood cells (RBCs). Recent studies show that clot surface also develops a fibrin film, which provides protection against wound infection and retains components such as RBCs within the clot.

Menopausal hormone therapy: assessing associations with breast and colorectal cancers by familial risk.

Menopausal users of hormone replacement therapy (HRT) are at increased breast cancer risk and decreased colorectal cancer (CRC) risk compared with individuals who have never used HRT, but these opposing associations may differ by familial risk of breast cancer and CRC. We harmonized data from 3 cohorts and generated separate breast cancer and CRC familial risk scores based on cancer family history. We defined moderate or strong family history as a risk score of 0.