Table 4.
Frequency distributions of the combined genotypes of SMAD4 SNP3 and SNP5 between gastric cancers and controls n (%)
| No. variant (protective) alleles of the combined genotypes1 | Cases (n = 322) | Controls (n = 351) | P2 | Adjusted OR (95% CI)3 |
| 0 | 138 (42.9) | 127 (36.2) | < 0.001 | |
| 1 | 167 (51.8) | 166 (42.3) | ||
| 2 | 17 (5.3) | 54 (15.4) | ||
| 3 | 0 (0.0) | 4 (1.1) | ||
| Dichotomized groups | ||||
| 0-1 | 305 (94.7) | 293 (83.5) | < 0.001 | 1.00 |
| 2-3 | 17 (5.3) | 58 (16.5) | 0.28 (0.16–0.49) |
1
0-3 represent the number of variants within the combined genotypes (0 = no variant and 1-3 = 1-3 variants); the variant (protective) alleles used for the calculation were the SNP3 C and SNP5 G alleles;
2
Two-sided χ2 test for the frequency distribution;
3
Odds ratios (ORs) were obtained from a logistic regression model with adjustment for age, sex, smoking status, and alcohol use. SNP: Single nucleotide polymorphism; CI: Confidence interval.