Table 2 Subgroup analysis of the prevalence of EBV infection in gastric cancer patients
Characteristics | Categories | No. of Studies | Pooled prevalence (%) (95% CI) | Heterogeneity test I2%, p-value | Differences between subgroups; χ2 test (p-value) |
|---|---|---|---|---|---|
Overall | – | 71 | 8.77 (7.73–9.92) | 83.2%, P < 0.01 | – |
Study design | Cross-sectional | 41 | 8.22 (6.90–9.77) | 88.2%, P < 0.01 | P = 0.15 |
Case-control | 30 | 9.71 (8.32–11.30) | 59.4%, P < 0.01 | ||
Publication date | ≤2005 | 42 | 8.91 (7.65–10.35) | 82.5%, P < 0.01 | P = 0.77 |
> 2005 | 29 | 8.56 (6.81–10.71) | 84.6%, P < 0.01 | ||
Sex | Male | 46 | 10.83 (9.43–12.40) | 73.2%, P < 0.01 | P < 0.0001†|
Female | 46 | 5.72 (4.27–7.64) | 74.9%, P < 0.01 | ||
Study location | Africa | 4 | 11.93 (5.97–22.44) | 76.8%, P < 0.01 | P = 0.64 |
America | 16 | 9.51 (7.45–12.07) | 76.8%, P < 0.01 | ||
Asia | 35 | 8.38 (7.15–9.80) | 84.1%, P < 0.01 | ||
Europe | 17 | 8.21 (5.82–11.46) | 80.4%, P < 0.01 | ||
Development status | Developed countries | 34 | 8.42 (7.11–9.94) | 82.1%, P < 0.01 | P = 0.64 |
Developing countries | 39 | 8.92 (7.40–10.73) | 83.5%, P < 0.01 | ||
Sample type | FFPE | 69 | 8.49 (7.54–9.55) | 79.9%, P < 0.01 | P < 0.0001†|
Biopsy | 2 | 20.36 (16.89–24.32) | 0%, P = 0.9 | ||
Lauren’s histological type | Intestinal type | 40 | 8.10 (6.64–9.83) | 69.2%, P < 0.01 | P = 0.31 |
Diffuse type | 40 | 9.41 (7.54–11.69) | 77.0%, P < 0.01 | ||
Tumor anatomical location | Cardia | 32 | 12.47 (10.39–14.89) | 24.8%, P = 0.1 | P = 0.0002†|
Body | 32 | 11.68 (9.96–13.65) | 32.0%, P = 0.04 | ||
Antrum | 35 | 6.29 (4.67–8.42) | 76.8%, P < 0.01 | ||
Depth of invasion | Early | 7 | 13.00 (9.20–18.06) | 0%, P = 0.71 | P = 0.45 |
Advanced | 7 | 10.80 (7.64–15.06) | 58.1%, P = 0.03 | ||
Tumor stage | I + II | 14 | 7.39 (5.79–9.39) | 29.5%, P = 0.14 | P = 0.36 |
III + IV | 14 | 8.80 (6.57–11.68) | 64.4%, P < 0.01 | ||
Lymph node invasion | Absent | 14 | 8.75 (6.02–12.55) | 57.9%, P < 0.01 | P = 0.91 |
Present | 14 | 9.00 (6.33–12.65) | 77.4%, P < 0.01 |