Formalin fixation on HER-2 and PD-L1 expression in gastric cancer: A pilot analysis using the same surgical specimens with different fixation times

Table 4 Programmed death-ligand 1 expression results of the programmed death-ligand 1 immunoreactive cases (n = 20)

Case No.	Used formalin	PD-L1 expression; P = 0.4605 (6 h-48 h vs 1 wk) 1				Assessment (Cut-off 1%)	Assessment (Cut-off 10%)	Assessment (Cut-off 50%)
		6 h	24 h	48 h	1 wk
2	10% F	10	10	10	1-9	+	+	-
4	10% F	80	80	90	90	+	+	+
5	10% F	0	0	0	1-9	+	-	-
8	10% F	0	0	1-9	1-9	+	-	-
9	10% F	0	1-9	0	1-9	+	-	-
10	10% F	40	30	30	40	+	+	-
11	10% F	1-9	0	10	10	+	+	-
12	10% F	1-9	1-9	1-9	0	+	-	-
14	10% F	100	1-9	30	60	+	+	+
16	10% F	1-9	10	1-9	1-9	+	+	-
18	10% F	20	60	40	40	+	+	+
19	10% F	1-9	1-9	1-9	0	+	-	-
20	10% F	80	80	20	1-9	+	+	+
21	10% F	1-9	0	1-9	1-9	+	-	-
25	10% NBF	10	0	10	0	+	+	-
27	10% NBF	20	70	30	1-9	+	+	+
29	10% NBF	1-9	1-9	0	1-9	+	-	-
30	10% NBF	100	100	100	100	+	+	+
31	10% NBF	0	1-9	10	1-9	+	+	-
32	10% NBF	70	80	90	90	+	+	+

¹Simultaneous tests for linear hypotheses based on a linear mixed effects model.

F: Formalin; NBF: Neutral buffered formalin.