Long-term dietary calcium intake and breast cancer risk in a prospective cohort of women
Autor: | Susanna C. Larsson, Leif Bergkvist, Alicja Wolk |
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Rok vydání: | 2009 |
Předmět: |
Oncology
medicine.medical_specialty Population Medicine (miscellaneous) Estrogen receptor chemistry.chemical_element Breast Neoplasms Calcium Cohort Studies Breast cancer Risk Factors Surveys and Questionnaires Internal medicine Confidence Intervals Odds Ratio medicine Humans Prospective Studies education Prospective cohort study Proportional Hazards Models Sweden Gynecology education.field_of_study Nutrition and Dietetics business.industry Cancer Middle Aged medicine.disease Diet Calcium Dietary Nutrition Assessment Receptors Estrogen chemistry Multivariate Analysis Cohort Female Receptors Progesterone business Follow-Up Studies Cohort study |
Zdroj: | The American Journal of Clinical Nutrition. 89:277-282 |
ISSN: | 0002-9165 |
Popis: | Background Calcium may potentially influence the risk of breast cancer because of its role in regulating cell proliferation, differentiation, and apoptosis. However, prospective studies of calcium intake in relation to breast cancer incidence are sparse. Objective The objective of this study was to prospectively examine and show the association, if any, of dietary calcium intake with risk of breast cancer by estrogen receptor (ER) and progesterone receptor (PR) status of the tumor. Design The Swedish Mammography Cohort is a population-based prospective cohort of 61,433 women who were cancer-free at enrollment in 1987-1990. Dietary calcium intake was assessed with a food-frequency questionnaire at baseline and again in 1997. Cox proportional hazards models were used to estimate rate ratios (RRs) and 95% CIs, adjusted for breast cancer risk factors. Results During an average of 17.4 y of follow-up, 2,952 incident cases of invasive breast cancer were ascertained. Dietary calcium intake was not associated with risk of overall breast cancer; the multivariate RR for the highest compared with the lowest quintile of calcium intake was 0.97 (95% CI: 0.87, 1.09; P for trend: 0.49). There was a statistically significant inverse trend for ER-negative/PR-negative (ER-/PR-) breast cancer (P for trend: 0.02); the multivariate RR for the comparison of extreme quintiles of calcium intake was 0.66 (95% CI: 0.44, 0.99). Calcium intake was not associated with ER-positive/PR-positive (ER+/PR+) or ER+/PR- tumors. Conclusions Our findings do not support an association between dietary calcium intake and overall breast cancer risk. The inverse relation between calcium intake and ER-/PR- breast cancer requires confirmation in other studies. |
Databáze: | OpenAIRE |
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