Objective: To assess the association of smoked meat intake, SULT1A1 polymorphism as well as their combined effects with breast cancer risk.
Methods: A total of 400 newly diagnosed breast cancer cases from a cancer hospital in Sichuan province and 400 healthy controls from participants of physical examination in a hospital in Chengdu city were recruited from May 2007 to July 2009. A valid questionnaire was designed to collect their demographic characteristics and breast cancer risk factors. Daily intake of foods was collected using semi-quantitative frequency questionnaire and then the daily intake of smoked meat was calculated and transformed to energy-adjusted smoked meat intake by the residual method. Gene sequencing was used to analyze SULT1A1 Arg213His genotypes. Multivariable conditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95%CIs).
Results: The energy-adjusted daily intake of smoked meat (Median (P₂₅, P₇₅)) was 8.65 (3.63, 18.44) g/d in cases and 4.44 (0.19, 8.71) g/d in controls. The frequency of SULT1A1 variant allele was 14.75% (59/400) among cases and 12.75% (51/400) among controls. High energy-adjusted daily intake of smoked meat (≥ 4.44 g/d) was significantly associated with breast cancer risk among premenopausal (OR = 2.31, 95%CI: 1.46 - 3.66) and postmenopausal subjects (OR = 3.13, 95%CI: 1.89 - 5.17). High energy-adjusted daily intake of smoked meat combined with carrying SULT1A1 variant allele elevated breast cancer risk among premenopausal (OR = 3.31, 95%CI: 1.66 - 6.62) and postmenopausal subjects (OR = 3.81, 95%CI: 1.79 - 8.10).
Conclusion: High smoked meat intake contributes to high risk of breast cancer. SULT1A1 variant allele increases breast cancer risk among subjects who were exposed to high smoked meat intake.