Table 2. Incidence and risk of gastric, colonic and pancreatic cancer by H. pylori infection and CagA seropositivity.
| Cancers | Total | Non-infected | H. pylori infected | ||
|---|---|---|---|---|---|
| IgG−/CagA− | IgG+/any CagA | IgG+/CagA− | IgG+/CagA+ | ||
| Gastric cancer (observations, n) | 9,497 | 4,760 | 4,737 | 2,127 | 2,610 |
| Cases (n) | 27 | 5 | 22 | 3 | 19 |
| Crude incidence rate† | 26.97 | 9.96 | 44.08 | 13.32 | 69.37 |
| HR1 (95% CI)‡ | — | Ref | 3.91 (1.48–10.38) | 1.16 (0.28–4.86) | 6.27 (2.33–16.86) |
| HR2 (95% CI)‡ | — | — | — | Ref | 5.57 (1.64–18.89) |
| Colonic cancer (observations, n) | 9,443 | 4,733 | 4,710 | 2,120 | 2,590 |
| Cases (n) | 108 | 50 | 58 | 32 | 26 |
| Crude incidence rate† | 108.94 | 100.61 | 117.32 | 143.55 | 95.78 |
| HR1 (95% CI)‡ | — | Ref | 1.07 (0.73–1.56) | 1.30 (0.83–2.03) | 0.87 (0.54–1.14) |
| HR2 (95% CI)‡ | — | — | — | Ref | 0.68 (0.40–1.14) |
| Pancreatic cancer (observations, n) | 9,504 | 4,766 | 4,738 | 2,128 | 2,610 |
| Cases (n) | 46 | 19 | 27 | 15 | 12 |
| Crude incidence rate† | 45.96 | 37.86 | 54.11 | 66.78 | 43.74 |
| HR1 (95% CI)‡ | — | Ref | 1.32 (0.73–2.39) | 1.61 (0.82–3.18) | 1.08 (0.52–2.24) |
| HR2 (95% CI)‡ | — | — | — | Ref | 0.67 (0.31–1.43) |
Abbreviations: CagA, cytotoxin-associated gene A; CI, confidence interval; IgG, immunoglobulin G; H. pylori, Helicobacter pylori; HR, hazard ratio.
†
Per 100,000 person-years.
‡
Adjusted for age, sex, education level, smoking status and alcohol consumption. HR1, comparing infected (IgG+) and non-infected (IgG–/CagA–) participants. HR2, comparing participants with IgG+/CagA+ and IgG+/CagA– H. pylori infection.