HBV and GICA
A total of 50,871 patients had HBV data from 2009 to 2020, the 2,375 GICA patients contracted gastric, colon, rectal or duodenal cancers, while the 48,496 non-oncologic controls were from the departments of psychiatry, neurology and cardiology. These patients suffered from congenital heart disease, coronary heart disease, schizophrenia, bipolar disorder, etc. 50,871 patients were aged 1–98 years, with a mean of 54.00±18.60 years, and the overall HBsAg positivity was 3.3%. Among patients with GICA, males (1,418, 59.7%) significantly outnumbered females (957, 40.3%) (P=0.014). A total of 1,1872 patients completed the 1:4 propensity score matching including 2,375 GICA patients and 9,497 controls. The L1 values before and after the matching were 0.170 and 0.003, respectively, suggesting a good match. There was no "Summary of unbalanced covariates" +|d|>0.25, indicating that all the matched variables reached equilibrium. There were 7,087 males and 4,785 females, respectively, showing no inter-group difference in gender (P=0.991). For the GICA and the control groups, the mean ages were 59.45±12.61 and 59.46±12.62 years, respectively (P=0.968). Among the 11,872 patients, the positivity rates of HBsAg, HBsAb, HBeAg, HBeAb and HBcAb were 3.4%, 58.9%, 0.2%, 12.3% and 27.0%, respectively. HBsAg positivity was 4.5% for the GICA group and 3.2% for the control group, showing a significant inter-group difference (P=0.002). It was found that the HBsAg positivity was significantly associated with an increased risk of gastrointestinal cancer (OR=1.427, 95% CI: 1.138–1.789). HBsAb positivity rates for the GICA and control groups were 56.2% and 59.6%, respectively, while the HBeAb positivity rates were 13.7% and 11.9%, both exhibiting significant inter-group differences. The HBsAb positivity prominently reduced the risk phase of GICA (P=0.002, OR=0.869, 95% CI: 0.793–0.951), while the HBeAb positivity prominently increased the GICA risk (P=0.021, OR=1.169, 95% CI: 1.024–1.335). No significant differences were noted in HBeAg (P=0.776) or HBcAb (P=0.153) between the two groups (Table 1). The mean ages of HBsAg-negative and HBsAg-positive patients in the GICA group were 59.5±12.7 and 58.2±11.6 years, respectively (P=0.089).
Allergy and GICA
From the Department of Medical Record Library, 2,9137 inpatients at the Department of Gastroenterology and Gastrointestinal Surgery between 2016 and 2020 were retrieved, of whom 2,352 had a history of allergies and the remaining 26,785 patients did not, with mean ages of 56.38±15.61 and 54.09±15.60 years, respectively (P=0.626). The incidence of allergy history among female patients was significantly higher at 1,281 (54.5%) than among male patients 1,071 (45.5%, P<0.001). The incidence of GICA among patients with an allergy history was significantly lower at 5.9% (139/2,352) than among patients without such history at 17.1% (4,592/26,785), showing a significant inter-group difference (P<0.001, OR=3.294, 95%CI: 2.767–3.921) (Table 2).
HBV and allergy
A total of 19,837 patients from 2017 to 2020 were matched between Department of Laboratory Medicine and Department of Medical Record Library, of whom 1,655 had a history of allergies and the remaining 18,182 patients did not, with means age of 52.97±19.73 and 50.00±19.36 years, respectively (P=0.388). The incidence of HBsAg-negative patients with a history of allergies was 8.4% (1,615/19,255), which was higher than 6.9% (40/582) among HBsAg-positive patients, although no significant inter-group difference was found (P=0.193). However, the incidence of allergies among HBsAb-positive patients was higher at 9.0% (923/10,246) than among HBsAb-negative patients at 7.6% (732/9,591), showing a significant inter-group difference (P<0.001, OR=0.835, 95% CI:0.754–0.924) (Table 3).