MMR testing in endometrial carcinoma

Methods

 microsatellite instability (MSI) analysis

• MSI (pentaplex panel)

 immunohistochemical (IHC) analysis of MMR protein expression

• MMR protein expression (IHC)
• A PMS2- and MSH6-antibody panel detected all cases with loss of MMR protein expression.
• The results of MSI and MMR protein expression are concordant in 655/696 cases.
• MSI and IHC analysis are highly concordant in endometrial cancer.
• This holds true for cases with subclonal loss of MMR protein expression.
• Discordant MMR-proficient/MSI-high cases (@<@1%), may be explained by POLE-EDM variants.

 MLH1 promoter hypermethylation,
 dinucleotide microsatellite markers
 somatic MMR
 POLE exonuclease domain (EDM) gene variants

Paywall references

 Practical guidance for mismatch repair-deficiency testing in endometrial cancer.
Stelloo E, Jansen AM, Osse EM, Nout RA, Creutzberg CL, Ruano D, Church DN, Morreau H, Smit VT, van Wezel T, Bosse T.
Ann Oncol. 2016 Oct 13.
PMID: 27742654