Programmed cell death ligand 1 (PD-L1, CD274) in cholangiocarcinoma – correlation with clinicopathological data and comparison of antibodies

Table 4 Meta-analysis of PubMed listed studies about PD-L1 immunohistochemistry in cholangiocarcinoma

Study	n=	Subtype	PD-L1 clone	Inflammatory cells, n/n (%)	Tumor cells, n/n (%)	Cut-off	Evaluation criteria
Ye et al., 2009	31	iCCA	28–8	n.a.	31/31 (100)	H-score^a, no cut-off described	cytoplasmatic + membranous
Gani et al., 2016	54	iCCA	5H1	31/54 (57)	39/54 (72)	% positive cells (> 5%)	membranous
Sabbatino et al., 2016	27	iCCA	22C3	27/27 (100)	8/27 (30)	H-score^a (> 25)	membranous
Sato et al., 2017	68	iCCA, eCCA	28–8	n.a.	1/23 (4) 4/45 (8)	% positive cells (< 5, > 5, > 10%)	n.a.
Ma et al., 2017	70	eCCA	EPR1161	37/70 (53)	30/70 (43)	Immunohistochemical Score*: > 3	cytoplasmatic + membranous
Fontugne et al., 2017	99	iCCA, pCCA	E1L3N	31/58 (53) 15/41 (37)	5/58 (9) 4/41 (9)	Strong staining in > 5% of tumor cells	membranous
Sangkhamanon et al., 2017	46	n.a.	5H1	n.a.	32/46 (70)	> 1% positive tumor cells	membranous
Walter et al., 2017	69	pCCA dCCA	E1L3N	12/40 (30) 9/29 (31)	4/40 (10) 4/29 (14)	H-score^a (> 3)	membranous

dCCA distal cholangiocarcinoma, eCCA extrahepatic cholangiocarcinoma, iCCA intrahepatic cholangiocarcinoma, pCCA perihilar cholangiocarcinoma.^a Immunohistochemical scoring system: percentage of cells with weak staining × 1 + percentage of cells with moderate staining × 2 + percentage of cells with strong staining × 3 = H-Score *Immunohistochemical scoring system: Stained cells (0:< 5%,1:5–25%, 2:26–50%,3:> 50%) x intensity (1+, 2+, 3+) , n.a., not available

ISSN: 1471-2407