Table 2

IHC loss and germline path_MMR detection rates in all index samples tested

AllTested (n)IHC loss%Tested germline (n)Germline PV% Germline
MLH1 loss36943489.4219166*34.5563 MLH1, 3 PMS2
PMS2 loss alone3694330.89261973.0819 PMS2
MSH2 loss36941985.361669054.2279 MSH2, 11 MSH6
MSH6 loss36942155.8217610257.9551 MSH6, 51 MSH2
Either MSH2 or MSH636942917.8823913054.3979 MSH2, 51 MSH6
Any loss369467218.1945621547.15
MSH6 loss alone3694531.43733852.0538 MSH6
Tested (n)Positive (n)
MLH1 loss hypermethylation268167†62.35711.75MLH1
MLH1 loss BRAF c.1799T>A1814524.8611327.3
No loss302200329195.785 MLH1, 7 MSH2, 3 MSH6, 4 PMS2
  • *This rose to 65/134 (48.5%) unmethylated samples.

  • †One patient with colorectal cancer had germline MLH1 methylation.

  • EC, endometrial cancer; IHC, immunohistochemistry; PV, pathogenic variant.