RESUMEN
BACKGROUND: Latinos are the largest minority group in the United States. We assessed cancer mortality by birthplace and generation status of Mexican Latinos in the Multiethnic Cohort. METHODS: We included 26â751 Latinos of Mexican origin and 6093 non-Latino Whites aged 45-74 years at cohort entry (1993-1996) from the California Multiethnic Cohort component. The Mexican Latinos comprised 42% first-generation Mexico-born immigrants, 42% second-generation (28% US-born with both parents Mexico-born and 14% US-born with 1 parent US-born and 1 parent Mexico-born), and 16% third-generation or more who were US-born with both parents US-born. Multivariable Cox models were used to calculate covariate adjusted hazard ratios and 95% confidence intervals for overall and site-specific cancer mortality by birthplace and generation status. All statistical tests were 2-sided. RESULTS: Cancer death rate was highest among the US-born with 1 parent US-born and 1 parent Mexico-born (age-adjusted rate = 471.0 per 100â000 person-years) and US-born with both parents US-born (age-adjusted rate = 469.0 per 100â000 person-years) groups. The US-born with both parents Mexico-born group had a 30% (hazard ratio = 1.30, 95% confidence interval = 1.18 to 1.44) higher risk of cancer death than the first-generation Mexico-born immigrants group, showing US birthplace was associated with an elevated cancer mortality. For cancer-specific mortality, US birthplace was positively associated with colorectal, liver and lung, and ovarian cancer (P values ranged from .04 to .005). Among US-born Mexican Latinos, generation status was not statistically significantly associated with overall cancer or site-specific cancer mortality. CONCLUSIONS: Our findings suggest that US birthplace is a risk factor for cancer death in Mexican Americans. Identification of the contributing factors is important to curtail patterns of increasing cancer mortality in US-born Mexican Latinos.
Asunto(s)
Hispánicos o Latinos , Neoplasias , Estudios de Cohortes , Humanos , México/epidemiología , Características de la Residencia , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Data on breastfeeding and breast cancer risk are sparse and inconsistent for Hispanic women. METHODS: Pooling data for nearly 6,000 parous Hispanic women from four population-based studies conducted between 1995 and 2007 in the United States and Mexico, we examined the association of breastfeeding with risk of breast cancer overall and subtypes defined by estrogen receptor (ER) and progesterone receptor (PR) status, and the joint effects of breastfeeding, parity, and age at first birth. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression. RESULTS: Among parous Hispanic women, older age at first birth was associated with increased breast cancer risk, whereas parity was associated with reduced risk. These associations were found for hormone receptor positive (HR+) breast cancer only and limited to premenopausal women. Age at first birth and parity were not associated with risk of ER- and PR- breast cancer. Increasing duration of breastfeeding was associated with decreasing breast cancer risk (≥25 vs. 0 months: OR = 0.73; 95% CI = 0.60, 0.89; Ptrend = 0.03), with no heterogeneity by menopausal status or subtype. At each parity level, breastfeeding further reduced HR+ breast cancer risk. Additionally, breastfeeding attenuated the increase in risk of HR+ breast cancer associated with older age at first birth. CONCLUSIONS: Our findings suggest that breastfeeding is associated with reduced risk of both HR+ and ER- and PR- breast cancer among Hispanic women, as reported for other populations, and may attenuate the increased risk in women with a first pregnancy at older ages.
Asunto(s)
Lactancia Materna/etnología , Neoplasias de la Mama/etnología , Hispánicos o Latinos/estadística & datos numéricos , Paridad , Receptores de Estrógenos/análisis , Receptores de Progesterona/análisis , Adulto , Anciano , Lactancia Materna/estadística & datos numéricos , Femenino , Humanos , México/epidemiología , Persona de Mediana Edad , Embarazo , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Consumption of green tea has been associated with reduced risk of breast cancer. Hormonal modulation has been suggested as one of the potential underlying mechanisms; however, it has yet to be fully elucidated in large, long-term human clinical trials. OBJECTIVE: We investigated the effects of decaffeinated green tea extract (GTE) on circulating sex hormones and insulin-like growth factor (IGF) proteins. METHODS: We conducted a placebo-controlled double-blind randomized clinical trial recruiting from 8 clinical centers in Minnesota. Participants were 538 healthy postmenopausal women randomly assigned to the GTE group (463 completed the study; mean age = 60.0 y) and 537 to the placebo group (474 completed; mean age = 59.7 y). Women in the GTE group orally took 4 decaffeinated capsules containing 1315 mg total catechins including 843 mg epigallocatechin-3-gallate daily for 1 y, whereas women in the placebo group took similar capsules containing no tea catechins. Blood sex hormones (estrone, estradiol, androstenedione, testosterone, and sex hormone-binding globulin) and IGF proteins (IGF-1 and IGF binding protein-3) were quantified at baseline and months 6 (for IGF proteins only) and 12, and were assessed as secondary outcomes of the study using a mixed-effect repeated-measures ANOVA model. RESULTS: Women in the GTE group had significantly higher blood total estradiol (16%; P = 0.02) and bioavailable estradiol (21%; P = 0.03) than in the placebo group at month 12. There was a statistically significant interaction between GTE supplementation and duration of treatment on estradiol and bioavailable estradiol (both Ps for interaction = 0.001). The catechol-O-methyltransferase genotype did not influence blood sex hormones before or after GTE supplementation. The circulating concentrations of IGF proteins were comparable between GTE and placebo groups at all 3 time points. CONCLUSION: These results suggest that a 12-mo GTE supplementation significantly increases circulating estradiol concentrations in healthy postmenopausal women. This trial was registered at clinicaltrials.gov as NCT00917735.
Asunto(s)
Neoplasias de la Mama , Catequina/farmacología , Hormonas Esteroides Gonadales/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Extractos Vegetales/farmacología , Té/química , Anciano , Catequina/química , Suplementos Dietéticos , Método Doble Ciego , Femenino , Humanos , Persona de Mediana Edad , Extractos Vegetales/química , PosmenopausiaRESUMEN
Gastric cancer incidence varies greatly worldwide, but is consistently twice as high in men than in women. The hormone-related factors hypothesized to be associated with lower risk of gastric cancer in women have not been fully explored in populations with a high background risk of gastric cancer. The Singapore Chinese Health Study (SCHS) is a prospective cohort study in which 34,022 of the participants enrolled between 1993 and 1998 were women between 45 and 74 years of age. Information on reproductive histories, hormone replacement therapy (HRT) and oral contraceptive (OC) use was collected through in-person interviews at baseline. As of December 31, 2013, 269 incident gastric cancer cases were identified. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate gastric cancer risk associations. Older age at natural menopause (≥55 versus <45 years: HR = 0.50, 95% CI: 0.25-0.99), type of menopause (other versus natural: HR = 0.48, 95% CI: 0.27-0.87) and greater years of menstrual cycling (fourth versus first quartile: HR = 0.67, 95% CI: 0.46-0.96) were associated with a decreased risk of gastric cancer. Ever use of OCs and HRT was also associated with reduced risk of gastric cancer; the multivariable-adjusted HRs (95% CIs) were 0.40 (0.17-0.90) for use of HRT >3 years and 0.67 (0.47-0.94) for ever use of OCs, compared with never use. Reproductive factors associated with a longer window of fertility and the use of exogenous hormones were shown to reduce gastric cancer development in a cohort of Chinese women with a high background risk of gastric cancer.