Table 2B.

PD-L1 expression in GEA Foundation Medicine cohort, by EGFR amplification status

	All GEA	EGJ	Gastric	GEA EGFR WT	GEA EGFR AMP
No. cases with PD-L1 IHC	632	377	255	591	41
PD-L1 tumor (%)
High positive	20 (3)	12 (3)	8 (3)	20 (3)	0
Low positive	89 (14)	56 (15)	33 (13)	84 (14)	5 (12)
Negative	523 (83)	309 (82)	214 (84)	487 (82)	36 (88)
PD-L1 TILs (%)
High positive	1 (0.2)	0	1 (0.4)	1 (0.2)	0
Low positive	110 (17)	72 (19)	38 (15)	105 (18)	5 (12)
Negative	521 (82)	305 (81)	216 (85)	485 (82)	36 (88)
PD-LI CPS (%)
Positive (≥1%)	166 (26)	106 (28)	60 (24)	159 (27)	7 (17)
Negative	466 (74)	271 (72)	195 (76)	432 (73)	34 (83)