Table 1.
Previous studies examining PD‐L1 expression of EGJ adenocarcinoma separated from that of gastric adenocarcinoma
| No. | Ref. | Year | Author (Country) | EGJ/esophagus or gastric (No. of cases) | Method | Tumor PD‐L1 positivity (%) | Stromal PD‐L1 positivity | Definition of PD‐L1 positivity | ||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 41 | 2018 | Weinberg et al (USA) |
EGJ (N = 119) Gastric (N = 462) |
IHC |
EGJ, 9.7% Gastric, 7.6% |
No data | Tumor, ≥5% tumor cell membranous expression | ||
| 2 | 42 | 2017 | Xing et al (China) |
EGJ (N = 8) Gastric (N = 4) |
IHC | EGJ, 66.7% Gastric, 58.3% | EGJ, 75% Gastric, 50% |
≥1% tumor cell expression Stroma, any immune cell expression (≥1%) |
||
| 3 | 43 | 2015 | Thompson et al (USA) |
EGJ (N = 5) Gastric (N = 29) |
IHC |
EGJ, 0% Gastric, 13.8% |
EGJ, 20% Gastric, 48.3% |
Tumor, ≥5% tumor cell expression Stroma, any immune cell expression (≥1%) |
||
| 4 | 44 | 2015 | Derks et al (USA) | EGJ/esophagus (N = 344) | IHC | EGJ/esophagus, 18% (mid‐proximal esophagus, 0.6% distal esophagus, 4.7% EGJ, 18.3%) | No data | Tumor, ≥5% tumor cell membranous expression (by tumor tissue microarray) | ||
| 5 | 45 | 2018 | Kollmann et al (Austria, Czech, Switzerland and USA) | EGJ/esophagus (N = 168) | IHC | EGJ/esophagus, 18% (Siewert type I, 26.8%; type II, 8.3%; type III, 8.3%) | No data | Tumor, any tumor cell expression (≥1%) | ||
| 6 | 46 | 2019 | Knief et al (Germany) | EGJ/esophagus (N = 135) | IHC | EGJ/esophagus, 48.1% | Combined positive score ≥1% | |||
| 7 | 47 | 2020 | Wang et al (China) | EGJ/esophagus (N = 96) | IHC | EGJ/esophagus, 11.5% (Siewert type I, 0%; type II, 7.9%; type III, 15.7%) | No data | Tumor, ≥5 stained tumor cells in a 400x field | ||
Abbreviations: EGJ, esophagogastric junction; IHC, immunohistochemistry.