Prenatal Arsenic Exposure on DNA Methylation of C18ORF8 and ADAMTS9 Genes of Newborns from the POSGRAD Birth Cohort Study.

Exposure to arsenic (As) is a public health problem associated with cancer (skin and colon) and it has been reported that epigenetic changes may be a potential mechanism of As carcinogenesis. It is pertinent to evaluate this process in genes that have been associated with cancer, such as ADAMTS9 and C18ORF8. Gestation and delivery data were obtained from the POSGRAD study. Exposure to As was measured in urine during pregnancy. Gene methylation was performed by sodium bisulfite sequencing; 26 CpG sites for the C18ORF8 gene and 21 for ADAMTS9 were analyzed. These sites are located on the CpG islands near the start of transcription. Sociodemographic characteristics were obtained by a questionnaire. The statistical analysis was performed using multiple linear regression models adjusted for potential confounders. Newborns with an As exposure above 49.4 µg g-1 showed a decrease of 0.21% on the methylation rate in the sites CpG15, CpG19, and CpG21 of the C18ORF8 gene (adjusted ß = -0.21, p-value = 0.02). No statistically significant association was found between prenatal exposure to As and methylation of the ADAMTS9 gene. Prenatal exposure to As was associated with decreased DNA methylation at the CpG15, CpG19, and CpG21 sites of the C18ORF8 gene. These sites can provide information to elucidate epigenetic mechanisms associated with prenatal exposure to As and cancer.

Association between consumption of nonessential energy-dense food and body mass index among Mexican school-aged children: a prospective cohort study.

BACKGROUND/OBJECTIVES: Obesity prevalence in Mexican children has increased rapidly and is among the highest in the world. We aimed to estimate the longitudinal association between nonessential energy-dense food (NEDF) consumption and body mass index (BMI) in school-aged children 5 to 11 years, using a cohort study with 6 years of follow-up. SUBJECTS/METHODS: We studied the offspring of women in the Prenatal omega-3 fatty acid supplementation, child growth, and development (POSGRAD) cohort study. NEDF was classified into four main groups: chips and popcorn, sweet bakery products, non-cereal based sweets, and ready-to-eat cereals. We fitted fixed effects models to assess the association between change in NEDF consumption and changes in BMI. RESULTS: Between 5 and 11 years, children increased their consumption of NEDF by 225 kJ/day (53.9 kcal/day). In fully adjusted models, we found that change in total NEDF was not associated with change in children's BMI (0.033 kg/m2, [p = 0.246]). However, BMI increased 0.078 kg/m2 for every 418.6 kJ/day (100 kcal/day) of sweet bakery products (p = 0.035) in fully adjusted models. For chips and popcorn, BMI increased 0.208 kg/m2 (p = 0.035), yet, the association was attenuated after adjustment (p = 0.303). CONCLUSIONS: Changes in total NEDF consumption were not associated with changes in BMI in children. However, increases in the consumption of sweet bakery products were associated with BMI gain. NEDF are widely recognized as providing poor nutrition yet, their impact in Mexican children BMI seems to be heterogeneous.

Latin American and the Caribbean Code Against Cancer 1st edition: Weight, physical activity, diet, breastfeeding, and cancer.

In Latin America and the Caribbean a considerable proportion of the population have excess body weight, do not meet the recommendations of physical activity and healthy diet, and have suboptimal rates of breastfeeding. Excess body weight is associated with at least 15 cancer sites, physical activity protects against three cancers, with some evidence suggesting a protective effect for eight more cancer sites, and sedentary behavior probably increases the risk of five cancer sites. Fiber and wholegrains protect against colorectal cancer, high intake of fruits and vegetables could reduce the risk of aerodigestive cancers; processed and red meat increase the risk of colorectal cancer; and very hot beverages are associated with esophageal cancer. Moreover, sugar-sweetened beverages and ultra-processed foods are a convincing cause for excess body weight, increasing cancer risk through this pathway, with some emerging evidence suggesting also direct pathways. Breastfeeding protects against breast cancer, and could protect against ovarian cancer. Taking this evidence into account, the Latin America and the Caribbean Code Against Cancer recommends the general public to maintain a healthy body weight, be physically active and limit sedentary behavior, eat a healthy diet (eat plenty of vegetables, fruits, wholegrains and legumes; avoid sugar-sweetened beverages and processed meat; and limit ultra-processed foods, red meat and very hot beverages), and breastfeed. Moreover, the Latin America and the Caribbean Code Against Cancer also includes a set of public policy recommendations for cancer prevention to inform policy makers and civil society about the need of policies to shape healthy environments and create opportunities to facilitate the adoption of the recommendations directed to the public.

Association between consumption of nonessential energy-dense food and body mass index among Mexican school-aged children: A prospective cohort study.

BACKGROUND/OBJECTIVES: Obesity prevalence in Mexican children has increased rapidly and is among the highest in the world. We aimed to estimate the longitudinal association between nonessential energy-dense food (NEDF) consumption and body mass index (BMI) in school-aged children 5 to 11 years, using a cohort study with 6 years of follow-up. SUBJECTS/METHODS: We studied the offspring of women in the Prenatal omega-3 fatty acid supplementation, child growth, and development (POSGRAD) cohort study. NEDF were classified into four main groups: chips and popcorn, sweet bakery products, non-cereal based sweets, and ready-to-eat cereals. We fitted fixed effects models to assess the association between change in 418.6 kJ (100 kcal) of NEDF consumption and changes in BMI. RESULTS: Between 5 and 11 years, children increased their consumption of NEDF by 225 kJ/day (53.9 kcal/day). In fully adjusted models, we found that change in total NEDF was not associated with change in children's BMI (0.033 kg/m2, [p=0.246]). However, BMI increased 0.078 kg/m2 for every 418.6 kJ/day (100 kcal/day) of sweet bakery products (p=0.035) in fully adjusted models. For chips and popcorn, BMI increased 0.208 kg/m2 (p=0.035), yet, the association was attenuated after adjustment (p=0.303). CONCLUSIONS: Changes in total NEDF consumption were not associated with changes in BMI in children. However, increases in the consumption of sweet bakery products were associated with BMI gain. NEDF are widely recognized as providing poor nutrition yet, their impact in Mexican children BMI seems to be heterogeneous.

Short-Term Ambient Air Ozone Exposure and Components of Metabolic Syndrome in a Cohort of Mexican Obese Adolescents.

Ambient air pollution is a major global public health concern; little evidence exists about the effects of short-term exposure to ozone on components of metabolic syndrome in young obese adolescents. The inhalation of air pollutants, such as ozone, can participate in the development of oxidative stress, systemic inflammation, insulin resistance, endothelium dysfunction, and epigenetic modification. Metabolic alterations in blood in components of metabolic syndrome (MS) and short-term ambient air ozone exposure were determined and evaluated longitudinally in a cohort of 372 adolescents aged between 9 to 19 years old. We used longitudinal mixed-effects models to evaluate the association between ozone exposure and the risk of components of metabolic syndrome and its parameters separately, adjusted using important variables. We observed statistically significant associations between exposure to ozone in tertiles in different lag days and the parameters associated with MS, especially for triglycerides (20.20 mg/dL, 95% CI: 9.5, 30.9), HDL cholesterol (-2.56 mg/dL (95% CI: -5.06, -0.05), and systolic blood pressure (1.10 mmHg, 95% CI: 0.08, 2.2). This study supports the hypothesis that short-term ambient air exposure to ozone may increase the risk of some components of MS such as triglycerides, cholesterol, and blood pressure in the obese adolescent population.

Docosahexaenoic Acid Effect on Prenatal Exposure to Arsenic and Atopic Dermatitis in Mexican Preschoolers.

Childhood atopic dermatitis (AD) is a chronic and recurrent health problem that involves multiple factors, particularly immunological and environmental. We evaluated the impact of docosahexaenoic acid (DHA) supplementation on prenatal arsenic exposure on the risk of atopic dermatitis in preschool children as part of the POSGRAD (Prenatal Omega-3 fatty acid Supplements, GRowth, And Development) clinical trial study in the city of Morelos, Mexico. Our study population included 300 healthy mother-child pairs. Of these, 146 were in the placebo group and 154 in the supplement group. Information on family history, health, and other variables was obtained through standardized questionnaires used during follow-up. Prenatal exposure to arsenic concentrations, which appear in maternal urine, was measured by inductively coupled plasma optical emission spectrometry. To assess the effect of prenatal arsenic exposure on AD risk, we ran a generalized estimating equation model for longitudinal data, adjusting for potential confounders, and testing for interaction by omega-3 fatty acid supplementation during pregnancy. The mean and SD (standard deviation) of arsenic concentration during pregnancy was 0.06 mg/L, SD (0.04 mg/L). We found a marginally significant association between prenatal arsenic exposure and AD (OR = 1.12, 95% CI: 0.99, 1.26); however, DHA supplementation during pregnancy modified the effect of arsenic on AD risk (p < 0.05). The results of this study strengthen the evidence that arsenic exposure during pregnancy increases the risk of atopic dermatitis early in life. However, supplementation with omega-e fatty acids during pregnancy could modify this association.

Consumption of industrial processed foods and risk of premenopausal breast cancer among Latin American women: the PRECAMA study.

Ultra-processed food intake has been linked to an increased risk of breast cancer in Western populations. No data are available in the Latin American population although the consumption of ultra-processed foods is increasing rapidly in this region. We evaluated the association of ultra-processed food intake to breast cancer risk in a case-control study including 525 cases (women aged 20-45 years) and 525 matched population-based controls from Chile, Colombia, Costa Rica and Mexico. The degree of processing of foods was classified according to the NOVA classification. Overall, the major contributors to ultra-processed food intake were ready-to-eat/heat foods (18.2%), cakes and desserts (16.7%), carbonated and industrial fruit juice beverages (16.7%), breakfast cereals (12.9%), sausages and reconstituted meat products (12.1%), industrial bread (6.1%), dairy products and derivatives (7.6%) and package savoury snacks (6.1%). Ultra-processed food intake was positively associated with the risk of breast cancer in adjusted models (OR T3-T1=1.93; 95% CI=1.11 to 3.35). Specifically, a higher risk was observed with oestrogen receptor positive breast cancer (ORT3-T1=2.44, (95% CI=1.01 to 5.90, P-trend=0.049), while no significant association was observed with oestrogen receptor negative breast cancer (ORT3-T1=1.87, 95% CI=0.43 to 8.13, P-trend=0.36). Our findings suggest that the consumption of ultra-processed foods might increase the risk of breast cancer in young women in Latin America. Further studies should confirm these findings and disentangle specific mechanisms relating ultra-processed food intake and carcinogenic processes in the breast.

Validity and reliability of the International Physical Activity Questionnaire (IPAQ) long-form in a subsample of female Mexican teachers.

OBJECTIVE: To evaluate the test-retest reliability and validity of the long-form International Physical Activity Questionnaire (IPAQ-long form). MATERIALS AND METHODS: A subsample of 86 teachers underwent telephone interviews and clinic visits in Mexico City. Through 22 months, physical activity (PA) levels were obtained from accelerometers (months 6 and 22) and IPAQ long-form (months 1, 3, 6, 9 and 12). Minutes per week of moderate (MPA), walking (WPA), vigorous (VPA) and moderate-to-vigorous physical activity (MVPA) were calculated for each intensity and domain. Variables were loga-rithmically transformed. Intra-class and Pearson correlations were used to determine the relationship between instru-ments. RESULTS: Test-retest reliability of the average IPAQs long-form varied across intensities and domains (ranged from r= 0.24 to r= 0.65). Minutes per week of VPA and MVPA ac-celerometer 1 (AC1) were fairly associated to International Physical Activity Questionnaire-long form 3 (IPAQ3) (r= 0.60 and r= 0.31, respectively) one week apart. CONCLUSIONS: IPAQ long-form is fairly reliable for MVPA and valid for as-sessing MVPA and VPA in a subsample of Mexican teachers.

Validity and reliability of the International Physical Activity Questionnaire (IPAQ) long-form in a subsample of female Mexican teachers / Validez y confiabilidad el Cuestionario Internacional de Actividad Física versión larga en una submuestra de maestras mexicanas

Abstract: Objective: To evaluate the test-retest reliability and validity of the long-form International Physical Activity Questionnaire (IPAQ-long form). Materials and methods: A subsample of 86 teachers underwent telephone interviews and clinic visits in Mexico City. Through 22 months, physical activity (PA) levels were obtained from accelerometers (months 6 and 22) and IPAQ long-form (months 1, 3, 6, 9 and 12). Minutes per week of moderate (MPA), walking (WPA), vigorous (VPA) and moderate-to-vigorous physical activity (MVPA) were calculated for each intensity and domain. Variables were logarithmically transformed. Intra-class and Pearson correlations were used to determine the relationship between instruments. Results: Test-retest reliability of the average IPAQs long-form varied across intensities and domains (ranged from r= 0.24 to r= 0.65). Minutes per week of VPA and MVPA accelerometer 1 (AC1) were fairly associated to International Physical Activity Questionnaire-long form 3 (IPAQ3) (r= 0.60 and r= 0.31, respectively) one week apart. Conclusions: IPAQ long-form is fairly reliable for MVPA and valid for assessing MVPA and VPA in a subsample of Mexican teachers.

Resumen: Objetivo: Evaluar la confiabilidad y validez del Cuestionario Internacional de Actividad Física versión larga (por sus siglas en inglés IPAQ-long form). Material y métodos: Un total de 86 maestras realizaron entrevistas y visitas a clínicas en la Ciudad de México. En un periodo de 22 meses, se obtuvieron los niveles de actividad física (AF) por medio de un acelerómetro (AC) (meses 6 y 22) y autorreporte de actividad física por medio del IPAQ versión larga (meses 1, 3, 6, 9 y 12). Se estimaron los minutos por semana de actividad física moderada (AFM), caminando (AFC), vigorosa (AFV) y actividad física moderada-vigorosa (AFMV) para cada intensidad y dominio. Las variables se transformaron logarítmicamente. Se utilizaron correlaciones de intraclase y de Pearson para determinar la relación de los minutos por semana de AFM, AFC, AFMV entre instrumentos. Resultados: La confiabilidad entre el promedio de los IPAQs varió entre intensidades y dominios (de r = 0.24 a r = 0.65). Los minutos por semana de AFV y AFMV del acelerómetro 1 (AC1) se asociaron con los del Cuestionario Internacional de Actividad Física 3 (IPAQ3) (r = 0.60 y r = 0.31, respectivamente) reportado una semana después. Conclusiones: La versión larga del IPAQ es confiable para estimar AFMV y válido para evaluar AFMV y AFV en una submuestra de maestras mexicanas.

Modification of the association by sex between the prenatal exposure to di(2-ethylhexyl) phthalate and fat percentage in a cohort of Mexicans schoolchildren.

INTRODUCTION: Children's overweight and obesity are global public health problems, children with obesity have grater obesity risk as adults, thus leading to develop cardiometabolic diseases. Previous studies have found positive and significant associations between the exposure to phthalates and body mass index and body composition. OBJECTIVE: To evaluate the modification of the association by sex between DEHP exposure during pregnancy and the percentage of body fat in a cohort of Mexican schoolchildren. MATERIAL AND METHODS: The sample was comprised by children which had previously participated in a POSGRAD longitudinal study. A subsample of 190 mother-children binomials were included. Mothers' DEHP concentrations and its metabolites had been measured in the second trimester of pregnancy: Mono-2-ethylhexyl phthalate (MEHP), Mono-2-ethyl-5-carboxypentyl phthalate (MECPP), Mono-2-ethyl-5-hidroxyhexyl phthalate (MEHHP), and Mono-2-ethyl-5-oxohexyl phthalate (MEOHP). The children's adipose mass was measured at age 8, 9, and 10. Longitudinal data were analyzed using the mixed effects linear regression model, with intercept and random slope, adjusted by important confounders and stratified by sex. RESULTS: We found a differentiated effect by sex, the exposure to DEHP during pregnancy significantly increases the adipose mass in boys. The average increase was 0.058% (p = 0.02) for every 1% variation in MECPP; 0.047% (p = 0.04) in MEHHP; 0.051% (p = 0.03) in MEOHP, and 0.066% (p = 0.007) in MECPP. CONCLUSIONS: The results suggest an effect differentiated by sex; with boys being the main ones affected by the prenatal exposure to phthalates. However, we cannot rule out effects in girls.

Infant Metabolome in Relation to Prenatal DHA Supplementation and Maternal Single-Nucleotide Polymorphism rs174602: Secondary Analysis of a Randomized Controlled Trial in Mexico.

BACKGROUND: Although DHA (22:6n-3) is critical for fetal development, results from randomized controlled trials (RCTs) of prenatal DHA supplementation report inconsistent effects on offspring health. Variants in fatty acid desaturase (FADS) genes that regulate the conversion of n-3 and n-6 essential fatty acids into their biologically active derivatives may explain this heterogeneity. OBJECTIVES: We investigated the effect of prenatal DHA supplementation on the offspring metabolome at age 3 mo and explored differences by maternal FADS single-nucleotide polymorphism (SNP) rs174602. METHODS: Data were obtained from a double-blind RCT in Mexico [POSGRAD (Prenatal Omega-3 Fatty Acid Supplementation and Child Growth and Development)] in which women (18-35 y old) received DHA (400 mg/d) or placebo from mid-gestation until delivery. Using high-resolution MS with LC, untargeted metabolomics was performed on 112 offspring plasma samples. Discriminatory metabolic features were selected via linear regression (P < 0.05) with false discovery rate (FDR) correction (q = 0.2). Interaction by SNP rs174602 was assessed using 2-factor ANOVA. Stratified analyses were performed, where the study population was grouped into carriers (TT, TC; n = 70) and noncarriers (CC; n = 42) of the minor allele. Pathway enrichment analysis was performed with Mummichog (P < 0.05). RESULTS: After FDR correction, there were no differences in metabolic features between infants whose mothers received prenatal DHA (n = 58) and those whose mothers received placebo (n = 54). However, we identified 343 differentially expressed features in the interaction analysis after FDR correction. DHA supplementation positively enriched amino acid and aminosugars metabolism pathways and decreased fatty acid metabolism pathways among offspring of minor allele carriers and decreased metabolites within the tricarboxylic acid cycle and galactose metabolism pathways among offspring of noncarriers. CONCLUSIONS: Our findings demonstrate differences in infant metabolism in response to prenatal DHA supplementation by maternal SNP rs174602 and further support the need to incorporate genetic analysis of FADS polymorphisms into DHA supplementation trials.This trial was registered at clinicaltrials.gov as NCT00646360.

Reproductive factors and risk of breast cancer in black South African women.

PURPOSE: Breast cancer (BC) is increasing in black South African women, but few studies have investigated its risk factors. METHODS: We conducted an analysis of reproductive factors and BC risk in the South African Breast Cancer (SABC) study-a population-based case-control study of black South African women from Soweto that included 399 cases and 399 matched controls. Information on lifestyle and reproductive history was obtained by interviews. Conditional logistic regression was used to determine the association of reproductive factors with BC, adjusting for potential confounding factors. RESULTS: Seventy-five percent of all BC cases were ER+, 66% PR+, 30% HER2+, and 16% TN. None of the reproductive variables were associated with BC overall or by subtype in the overall population, nor in pre- (n = 135 cases) or in post-menopausal women separately. In HIV-negative pre-menopausal women (n = 97 cases), later age at first pregnancy and longer time between menarche and first full-time pregnancy were inversely related to BC risk (OR 0.89 (95% CI 0.82-0.97; and 0.93 95% CI 0.86-1.01, respectively). CONCLUSION: In this population of black South African women, reproductive factors were not associated with BC risk.

Pro-Inflammatory Diet Is Associated with Adiposity during Childhood and with Adipokines and Inflammatory Markers at 11 Years in Mexican Children.

There is limited evidence about the inflammatory potential of diet in children. The aim of this study was to evaluate the association between the Children's Dietary Inflammatory Index (C-DII) from 5 to 11 years with adiposity and inflammatory biomarkers in Mexican children. We analyzed 726 children from a birth cohort study with complete dietary information and measurements to evaluate adiposity at 5, 7 and 11 y and 286 children with IL-6, hsCRP, leptin and adiponectin information at 11 y. C-DII trajectories were estimated using latent class linear mixed models. We used linear mixed models for adiposity and logistic and multinomial regression for biomarkers. In girls, each one-point increase in C-DII score was associated with greater adiposity (abdominal-circumference 0.41%, p = 0.03; skinfold-sum 1.76%, p = 0.01; and BMI Z-score 0.05, p = 0.01). At 11 y the C-DII was associated with greater leptin (34% ≥ 13.0 ng/mL, p = 0.03) and hsCRP concentrations (29% ≥ 3.00 mg/L, p = 0.06) and lower adiponectin/leptin ratio (75% < 2.45, p = 0.02). C-DII trajectory 3 in boys was associated with a 75.2% (p < 0.01) increase in leptin concentrations and a 37.9% decrease (p = 0.02) in the adiponectin/leptin ratio. This study suggests that the inflammatory potential of diet may influence adiposity in girls and the homeostasis of adipose tissue and chronic subclinical inflammation in 11-year-old children.

Prenatal exposure to VOCs and NOx and lung function in preschoolers.

BACKGROUND: Several studies have shown that exposure to air pollutants affects lung growth and development and can result in poor respiratory health in early life. METHODS: We included a subsample of 772 Mexican preschoolers whose mothers participated in a Prenatal Omega-3 fatty acid Supplements, GRowth, And Development birth cohort study with the aim to evaluate the impact of prenatal exposure to volatile organic compounds and nitrogen oxides on lung function measured by oscillation tests. The preschoolers were followed until 5 years of age. Anthropometric measurements and forced oscillation tests were performed at 36, 48, and 60 months of age. Information on sociodemographic and health characteristics was obtained during follow up. Prenatal exposure to volatile organic compounds and nitrogen oxides was evaluated using a land use regression models and the association between them was tested using a lineal regression and longitudinal linear mixed effect models adjusting for potential confounders. RESULTS: Overall, the mean (standard deviation) of the measurements of respiratory system resistance and respiratory system reactance at 6, 8, and 10 Hz during the follow-up period was 11.3 (2.4), 11.1 (2.4), 10.3 (2.2) and -5.2 (1.6), -4.8 (1.7), and -4.6 hPa s L-1 (1.6), respectively. We found a significantly positive association between respiratory resistance (ßRrs6 = 0.011; 95%CI: 0.001, 0.023) (P < .05) and prenatal exposure to nitrogen dioxide and a marginally negatively association between respiratory reactance (ßXrs6 = -11.40 95%CI: -25.26, 1.17 and ßXrs8 = -11.91 95%CI: -26.51, 1.43) (P = .07) and prenatal exposure to xylene. CONCLUSION: Prenatal exposure to air pollutants was significantly associated with the alteration of lung function measured by oscillation tests in these preschool children.

Synergistic action of folate intake and testosterone associated with breast cancer risk.

The amount of irreparable DNA damage is a function of the rate of cell division, and the association between sex hormones and the risk of breast cancer has been explained by an increase in cell division. Folate intake insufficiency leads to disturbances in DNA replication and DNA repair. We hypothesized that folate intake insufficiency and high serum concentrations of sex hormones act synergistically on the risk of breast cancer. The aim of this study was to investigate the interaction between sex hormones (exposure of interest A) and dietary folate intake (exposure of interest B) on the risk of breast cancer. We included 342 breast cancer primary postmenopausal cases and 294 controls obtained from a large population-based case-control study. Multiple conditional logistic regression models were used for the analysis and interactions were tested. The joint effect of the lowest dietary folate intake (T1 < 259.40 mg/d) and the highest serum concentration of testosterone (T3 ≥ 0.410 on the risk of breast cancer was odds ratio = 9.18 (95% confidence interval 2.56-32.88) when compared to the lowest-risk category, namely, the group of women with the highest dietary folate intake (T3 > 381.29 mg/d) and the lowest serum concentration of testosterone (T1 ≤ 0.25 pg/mL). There were some indications that the estimated join effect was greater than the product of the estimated effects alone (P = .001). These findings have important public health implications with respect to reducing the risk of the most frequent cancer in women worldwide.

Project profile: a multicenter study on breast cancer in young women in Latin America (PRECAMA study).

OBJECTIVE: To describe the rationale and the methodology of a multicenter project to study the etiology of breast cancer in young Latin American women. MATERIALS AND METHODS: The International Agency for Research on Cancer has established an international collaborative population-based case-control study in four countries in Latin America: Chile, Colombia, Costa Rica, and Mexico (the PRECAMA study). Standardized methodologies were developed to collect information on reproductive variables, lifestyle, anthropometry, diet, clinical and pathological data, and biological specimens. The study will be extended to other countries in the region. CONCLUSIONS: PRECAMA is unique in its multidisciplinary approach that combines genetics, genomics, and metabolomics with lifestyle factors. Then data generated through this project will be instrumental to identify major risk factors for molecular subtypes of breast cancer in young women, which will be important for pre- vention and targeted screening programs in Latin America.

OBJETIVO: Describir la justificación y la metodología para el establecimiento de un proyecto multicéntrico sobre el cáncer de mama en mujeres jóvenes de América Latina. MATERIAL Y MÉTODOS: La Agencia Internacional para la Investigación del Cáncer (IARC) ha establecido un estudio colaborativo internacional de casos y controles con base poblacional en cuatro países de América Latina: Chile, Colombia, Costa Rica y México (el estudio PRECAMA). Se han desarrollado metodologías estandarizadas para recolectar información sobre variables reproductivas, estilos de vida, antropometría y dieta, datos clínicos y patológicos y muestras biológicas. CONCLUSIONES: PRECAMA es único en su enfoque multidisciplinario. Los datos generados a través de este proyecto serán fundamentales para identificar los principales factores de riesgo del cáncer de mama en mujeres jóvenes. Los hallazgos serán relevantes para la prevención y los programas de detección oportuna en América Latina, con beneficios clínicos inmediatos.

Project profile: a multicenter study on breast cancer in young women in Latin America (PRECAMA study) / Perfil de Proyecto: Un estudio multicéntrico sobre el cáncer de mama en mujeres jóvenes en América Latina (estudio PRECAMA)

Abstract: Objective: To describe the rationale and the methodology of a multicenter project to study the etiology of breast cancer in young Latin American women. Materials and methods: The International Agency for Research on Cancer has established an international collaborative population-based case-control study in four countries in Latin America: Chile, Colombia, Costa Rica, and Mexico (the PRECAMA study). Standardized methodologies were developed to collect information on reproductive variables, lifestyle, anthropometry, diet, clinical and pathological data, and biological specimens. The study will be extended to other countries in the region. Conclusion: PRECAMA is unique in its multidisciplinary approach that combines genetics, genomics, and metabolomics with lifestyle factors. The data generated through this project will be instrumental to identify major risk factors for molecular subtypes of breast cancer in young women, which will be important for prevention and targeted screening programs in Latin America.

Resumen: Objetivo: Describir la justificación y la metodología para el establecimiento de un proyecto multicéntrico sobre el cáncer de mama en mujeres jóvenes de América Latina. Material y métodos: La Agencia Internacional para la Investigación del Cáncer (IARC) ha establecido un estudio colaborativo internacional de casos y controles con base poblacional en cuatro países de América Latina: Chile, Colombia, Costa Rica y México (el estudio PRECAMA). Se han desarrollado metodologías estandarizadas para recolectar información sobre variables reproductivas, estilos de vida, antropometría y dieta, datos clínicos y patológicos y muestras biológicas. Conclusión: PRECAMA es único en su enfoque multidisciplinario. Los datos generados a través de este proyecto serán fundamentales para identificar los principales factores de riesgo del cáncer de mama en mujeres jóvenes. Los hallazgos serán relevantes para la prevención y los programas de detección oportuna en América Latina, con beneficios clínicos inmediatos.

A follow-up study after an improved cookstove intervention in rural Mexico: Estimation of household energy use and chronic PM2.5 exposure.

The benefits of improved biomass cookstoves (ICS) depends on their adoption and sustained use. Few studies have documented if and how they are used more than five years after being introduced. We conducted a 9-year prospective cohort study among young rural women in the highlands of Michoacan, Mexico. Participants had received a Patsari ICS during a community trial either in 2005 or 2006. With retrospective information collected in 2012-13, we studied the households' energy use, ICS survival, and cooking practices during the follow-up period. Using an exposure model constructed with personal PM2.5 measurements in a subsample of homes at the time of the initial trial in 2005, we estimated the exposure associated with different energy use patterns during the follow-up period. The ICS had a mean lifespan of 4 years, after which more than half of the stoves were not in use; therefore, the use of open fire increased, particularly among the indigenous communities. ICS use peak was achieved two years after the initial trial, either exclusively or combined with open fire. Yearly household energy use and other variables were used to estimate chronic air pollution exposure. Mean PM2.5 exposure during the follow-up period ranged from 51 to 319 µg/m3; the median was 102 and 146 µg/m3 for mainly ICS and mainly open fire use, respectively. The ICS has a useful period after which it needs maintenance, repair, or replacement. Unfortunately, many programs have not afforded a follow-up component. Exposure to biomass smoke air pollutants can be reduced by using an ICS instead of the traditional open fire. Household energy strategies should ensure equitable access to clean energy options adapted to local needs and preferences with culturally appropriate technology implemented on a sustainable perspective.

Association of a Priori-Defined Dietary Patterns with Anthropometric Measurements: A Cross-Sectional Study in Mexican Women.

This cross-sectional study aimed to evaluate associations between a priori defined dietary patterns and anthropometric measures in Mexican women. A total of 1062 women aged 35 to 69 years old from the control participants of the CAMA (Cancer de Mama) study, a multi-center population-based case-control study on breast cancer conducted in Mexico, were interviewed and dietary intakes were assessed using questionnaires. The following indices were derived from these data: Dietary Approaches to Stop Hypertension (DASH) score, the Healthy Eating Index (HEI), the Mediterranean Diet Score (aMED), the Diet Quality Index (DQI), glycemic index (GI) and glycemic load (GL). Adjusting for age, center, educational level, physical activity and energy intake, a high GI was positively associated with a higher body mass index (BMI) and waist circumference (WC). Higher adherence to aMED was associated with lower WC and waist-to-hip ratio (WHR) but no significant association was observed with other a priori dietary patterns. In this population of Mexican women, higher adherence to Mediterranean diet was associated with lower WC but other a priori dietary scores appeared to be of limited value in exploring the association between diet and anthropometric measures.

Comprehensive Analysis of Germline Variants in Mexican Patients with Hereditary Breast and Ovarian Cancer Susceptibility.

Hereditary breast and ovarian cancer syndrome (HBOC) represents 5⁻10% of all patients with breast cancer and is associated with high-risk pathogenic alleles in BRCA1/2 genes, but only for 25% of cases. We aimed to find new pathogenic alleles in a panel of 143 cancer-predisposing genes in 300 Mexican cancer patients with suspicion of HBOC and 27 high-risk patients with a severe family history of cancer, using massive parallel sequencing. We found pathogenic variants in 23 genes, including BRCA1/2. In the group of cancer patients 15% (46/300) had a pathogenic variant; 11% (33/300) harbored variants with unknown clinical significance (VUS) and 74% (221/300) were negative. The high-risk group had 22% (6/27) of patients with pathogenic variants, 4% (1/27) had VUS and 74% (20/27) were negative. The most recurrent mutations were the Mexican founder deletion of exons 9-12 and the variant p.G228fs in BRCA1, each found in 5 of 17 patients with alterations in this gene. Rare VUS with potential impact at the protein level were found in 21 genes. Our results show for the first time in the Mexican population a higher contribution of pathogenic alleles in other susceptibility cancer genes (54%) than in BRCA1/2 (46%), highlighting the high locus heterogeneity of HBOC and the necessity of expanding genetic tests for this disease to include broader gene panels.