TABLE 2.
Methodologies for determining PD-L1 expression and HPV status
| HPV status |
PD-L1 expression |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Author (year) | N | Method | Evaluated | + | − | Method | Cutoffb | + | − |
| Cohen (2019) | 247 | OP Ventana p16 IHC, >70% is pos | a | 61 (a) | a | Agilent PD-L1 IHC 22C3 pharmDx | CPS > 1% | 196 (79) | 50 (20) |
| Zandberg (2019) | 112 | p16 IHC or PCR | 99 | 34 (34) | 65 (65) | Ventana PD-L1 (SP263) Assay | TC > 25% | 111 | 0 |
| Colevas (2018) | 32 | PCR | 28 | 13 (46) | 12 (43) | Ventana PD-L1 (SP142) Assay | IC > 5% | 25 (78) | 7 (22) |
| Ferris (2018)c | 240 | OP p16 IHC, >70% is pos | 120 | 64 (53) | 56 (47) | Dako PD-L1 IHC 28-8 pharmDx | CPS > 1% | 96 (40) | 76 (31) |
| Siu (2018) | 67 | a | 67 | 18 (27) | 49 (73) | Ventana PD-L1 (SP263) Assay | TC < 25% | 0 | 65 |
| Bauml (2017) | 171 | Institutional protocold | 168 | 37 (22) | 131 (78) | Dako PD-L1 IHC 22C3 pharmDx | CPS > 1% | 140 (82) | 26 (15) |
| Hsu (2017) | 27 | a | a | a | a | QualTek Molecular Labs | CPS > 1% | 27 | a |
| Chow (2016) | 132 | a | a | 28 (21) | 104 (79) | Agilent Dako PD-L1; Merck 22C3 pharmDx | CPS > 1%, TPS > 1% | a | a |
| Seiwert (2016) | 60 | p16 IHC, >70% is pos | 60 | 23 (38) | 37 (62) | Agilent Dako PD-L1; Merck 22C3 pharmDx | CPS > 1% | 60 | 0 |
Abbreviations: OP, oropharyngeal; TC, tumor cell staining; IC, area of tumor area positive for immune cells; CPS, Combined Positive Score; IHC, immunohistochemistry; PCR, polymerase chain reaction.
a
Not reported or not tested.
b
Various methodologies reported in the included studies, if more than one methodology was reported, CPS ≥1 was determined to indicated positivity.
c
Data from most recent study are presented here; if data in most recent study were not specifically reported, then data from prior studies are reported.
d
Non-oropharyngeal tumors were assumed to be HPV negative.