Molecular testings of endometrial cancer: talk from Dr. Anca Oniscu from BAGP teaching session

Only POLE shows clearly favorable survival compared to copy-number high (TP53) group

FIGO 2023 for endometrial cancer

1. Aggressive histotypes include serous, clear cell, mesonephric-like, mucinous of gastrointestinal type.

2. Molecular testing if possible should be performed on all endoemtrial cancers; POLE guide prognosis; MMR guide treatment like immuno checkpoint inhibitors or possible Lynch syndrome.

   
   

   

   
   

   

   P53 reported as aberrant, subclonal, and wild type.

MLH1 and PMS2 are linked and MLH1 is the dominant; MSH2 and MSH6 are linked where MSH2 is the dominant. Important thing here is if you have loss of MLH1 with or without PMS2 or MSH6, do MLH1 promoter hyerpmethylation

Mismatch repair testing:

testing for microsatellite instability by PCR. In this picture, the tumor shows some shoulder effect on these loci, if only one locus show shoulder, it's MSI low; if more than two it's MSI high.

MMR IHC interpretation need positive stroma lymphocytes

MLH1 loss and no mLH1 hypermethylation, no germline mutation then do NGS for double somatic mutation

In this case, germline testing should be performed. despite PCR showed MSS. You can see weak staining of MSH2

Credit: Dr. Anca Oniscu, MD from BAGP teaching session