Table 9B.

Comparison of methylthioadenosine phosphorylase (MTAP) immunohistochemistry (IHC) and CDKN2A fluorescence in situ hybridization (FISH) homozygous and hemizygous deletion, and no loss (retention).

CDKN2A FISH scoring	MTAP IHC loss	MTAP IHC retained	Concordance between MTAP IHC and CDKN2A FISH hemizygous loss, homozygous loss and no loss
Homozygous Loss (n=44)	28 (includes one case of partial loss)	16	64% (28/44)
Hemizygous Loss (n=10)	1	9	90% (9/10)
No Loss (n=2)	0	2	100% (2/2)
Overall Concordance MTAP IHC and CDKN2A FISH as a test			70% (39/56)