title: Hormonal therapy and risk of breast cancer in mexican women.
abstract: The use of hormonal therapies, including hormonal contraceptives (HC) and postmenopausal hormone replacement therapy (HRT) have been shown to influence breast cancer (BC) risk. However, the variations of these effects among populations and ethnic groups are not completely documented, especially among Hispanic women. We evaluated the association between HC and premenopausal BC risk, and between HRT and postmenopausal BC risk in Mexican women. Data from a Mexican multi-center population-based case-control study ofwomen aged 35 to 69 years were analysed. A total of 1000 cases and 1074 matched controls were recruited between 2004 and 2007. Information on hormonal therapy was collected through a structured questionnaire. Results were analysed using conditional logistic regression models. Overall, HC were used by 422/891 (47.3%) premenopausal women and HRT was used by 220/1117 (19.7%) postmenopausal women. For HC, odds ratios (ORs) for BC were 1.11 (95% confidence interval (CI): 0.82, 1.49) for current users and 1.68 (95% CI: 0.67, 4.21) for ever-users. No clear effect of duration of use was observed. For HRT, the OR for BC was significantly increased in ever users (OR: 1.45; 95% CI: 1.01, 2.08). A non-significant increased risk was observed for combined estrogen/progestin, (OR =  1.85; 95% CI: 0.84, 4.07) whereas no effect was observed for the use of estrogen alone (OR = 1.14; 95% CI: 0.68, 1.91). Our results indicate that, HC had a non-significant effect on the risk of pre-menopausal BC, but suggested that injected contraceptives may slightly increase the risk, whereas HRT had a significant effect on post-menopausal BC in this population. This study provides new information about the effects of HC and HRT on BC risk in a Mexican population, which may be of relevance for the population of Latin America as a whole.
authors.affiliation: Nutrition and Metabolism Section/Nutritional Epidemiology Group, International Agency for Research on Cancer, Lyon, France.
authors.forename: Amina
authors.initials: A
authors.lastname: Amadou
authors.forename: Alban
authors.initials: A
authors.lastname: Fabre
authors.forename: Gabriela
authors.initials: G
authors.lastname: Torres-Mejía
authors.forename: Carolina
authors.initials: C
authors.lastname: Ortega-Olvera
authors.forename: Angélica
authors.initials: A
authors.lastname: Angeles-Llerenas
authors.forename: Fiona
authors.initials: F
authors.lastname: McKenzie
authors.forename: Carine
authors.initials: C
authors.lastname: Biessy
authors.forename: Pierre
authors.initials: P
authors.lastname: Hainaut
authors.forename: Isabelle
authors.initials: I
authors.lastname: Romieu
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D016022:Case-Control Studies; D015914:Estrogen Replacement Therapy / Q000009:adverse effects; D004967:Estrogens / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D011372:Progestins / Q000009:adverse effects / Q000627:therapeutic use; D012307:Risk Factors
chemical_list: D004967:Estrogens; D011372:Progestins