Joint effects of the MTHFR C677T polymorphism and HRT use at baseline on breast cancer risk
| Duration (y) . | CC . | . | CT . | . | TT . | . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | n* . | OR (95% CI)† . | n . | OR (95% CI) . | n . | OR (95% CI) . | ||||||
| HRT use | ||||||||||||
| Never | 240/619 | 1.00 | 170/418 | 0.95 (0.74-1.21) | 63/137 | 1.01 (0.71-1.43) | ||||||
| 1-3 | 146/325 | 1.07 (0.83-1.38) | 143/262 | 1.14 (0.87-1.48) | 32/65 | 0.96 (0.60-1.53) | ||||||
| >3 | 129/180 | 1.35 (1.01-1.79) | 121/147 | 1.48 (1.10-1.99) | 31/53 | 0.94 (0.58-1.54) | ||||||
| P | 0.35‡ | |||||||||||
| Duration (y) . | CC . | . | CT . | . | TT . | . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | n* . | OR (95% CI)† . | n . | OR (95% CI) . | n . | OR (95% CI) . | ||||||
| HRT use | ||||||||||||
| Never | 240/619 | 1.00 | 170/418 | 0.95 (0.74-1.21) | 63/137 | 1.01 (0.71-1.43) | ||||||
| 1-3 | 146/325 | 1.07 (0.83-1.38) | 143/262 | 1.14 (0.87-1.48) | 32/65 | 0.96 (0.60-1.53) | ||||||
| >3 | 129/180 | 1.35 (1.01-1.79) | 121/147 | 1.48 (1.10-1.99) | 31/53 | 0.94 (0.58-1.54) | ||||||
| P | 0.35‡ | |||||||||||
No. cases/no. controls (in comparison with Table 4, an additional 14 cases and 40 controls were excluded due to missing information on HRT duration).
ORs (95% CIs) adjusted for ethnicity and age at blood draw.
P value derived from a likelihood ratio test comparing a model with main effects for the MTHFR C677T genotype and the HRT use (Never, 1-3 years of use, >3 years of use), and a model with main effects and interaction terms (df, 4).