OBJECTIVE: It has been suggested that dietary phytoestrogen intake during adolescence may reduce the risk of developing breast cancer. This population-based case-control study evaluated the association between adolescent dietary phytoestrogen intake and adult breast cancer risk among women in Ontario, Canada. METHODS: Pathology-confirmed, population-based breast cancer cases, aged 25-74 years, diagnosed between June 2002 and April 2003, were identified using the Ontario Cancer Registry. Population-based controls were recruited, and matched to cases within 5-year age groups. Adolescent phytoestrogen intake was obtained using a brief food frequency questionnaire (n = 3,024 cases, n = 3,420 controls). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Higher phytoestrogen intake (both isoflavones and lignans) during adolescence was associated with a reduced breast cancer risk, and a monotonic trend was observed from the lowest to the highest quartile (OR [Q2] = 0.91, 95% CI 0.79-1.04, OR[Q3] = 0.86, 95% CI 0.75-0.98, and OR[Q4] = 0.71, 95% CI 0.62-0.82, p-trend < 0.001). CONCLUSION: Adolescent dietary phytoestrogen intake may be associated with a decreased risk of adult breast cancer. If verified, this finding has important implications with regard to breast cancer prevention since diet is a potentially modifiable factor.
OBJECTIVE: It has been suggested that dietary phytoestrogen intake during adolescence may reduce the risk of developing breast cancer. This population-based case-control study evaluated the association between adolescent dietary phytoestrogen intake and adult breast cancer risk among women in Ontario, Canada. METHODS: Pathology-confirmed, population-based breast cancer cases, aged 25-74 years, diagnosed between June 2002 and April 2003, were identified using the Ontario Cancer Registry. Population-based controls were recruited, and matched to cases within 5-year age groups. Adolescent phytoestrogen intake was obtained using a brief food frequency questionnaire (n = 3,024 cases, n = 3,420 controls). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Higher phytoestrogen intake (both isoflavones and lignans) during adolescence was associated with a reduced breast cancer risk, and a monotonic trend was observed from the lowest to the highest quartile (OR [Q2] = 0.91, 95% CI 0.79-1.04, OR[Q3] = 0.86, 95% CI 0.75-0.98, and OR[Q4] = 0.71, 95% CI 0.62-0.82, p-trend < 0.001). CONCLUSION: Adolescent dietary phytoestrogen intake may be associated with a decreased risk of adult breast cancer. If verified, this finding has important implications with regard to breast cancer prevention since diet is a potentially modifiable factor.
Authors: Carol J Fabian; Bruce F Kimler; Carola M Zalles; Jennifer R Klemp; Brian K Petroff; Qamar J Khan; Priyanka Sharma; Kenneth D R Setchell; Xueheng Zhao; Teresa A Phillips; Trina Metheny; Jennifer R Hughes; Hung-Wen Yeh; Karen A Johnson Journal: Cancer Prev Res (Phila) Date: 2010-08-19
Authors: Fitriya N Dewi; Charles E Wood; Cynthia J Lees; Cynthia J Willson; Thomas C Register; Janet A Tooze; Adrian A Franke; J Mark Cline Journal: Cancer Prev Res (Phila) Date: 2013-06-14