Table 3

MSIa and IHC results of the Bethesda-negative groups

See Table 1<$REFLINK> for explanation of the groups.

Intact expression of all 4 proteinsAbsent expression ≥ 1 protein
Group 5Group 6Group 7Group 8Group 5Group 6Group 7Group 8
Total no. of cases252246226981
No. of MSS222045200000
No. of MSI-L31101 b1 c00
No. of MSI-H01025 d8 e8 f1 g
  • a MSI, microsatellite instability; IHC, immunohistochemistry; MSS, microsatellite stability.

  • b Abrogation of MSH6.

  • c Abrogation of MSH6.

  • d Abrogation of MLH1, or PMS2, or MLH1/PMS2 (2 cases), or MSH2/MSH6.

  • e Abrogation of MLH1/MSH6, PMS2, MSH2, or MSH2/MSH6, or MSH6 (4 cases).

  • f Abrogation of MLH1/PMS2 (2 cases), or PMS2, or MSH2, or MSH6 (2 cases), MSH2/MSH6, or MSH2/MSH6/PMS2.

  • g Abrogation of MLH1/PMS2.