Table 3.

Concordance between MSI and IHC in CRC from Young Patients (<60 Years)

MMR expression (n = 208)	MSI−	MSI+
No loss*	187	1†
Complete loss‡	1§	19

^*Defined as any expression for all four MMR proteins. Includes cases showing weak, clonal, or heterogeneous staining, or variable staining intensity. 

^†Clonal losses of both MSH2 and MSH6. 

^‡Defined as complete loss of at least one MMR protein. 

^§Complete loss of MSH6 expression only.