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Abstract Background Breast cancer incidence is increasing rapidly in Latin America, with a higher proportion of cases among young women than in developed countries. Studies have linked inflammation to breast cancer development, but data is limited in premenopausal women, especially in Latin America. Methods We investigated the associations between serum biomarkers of chronic inflammation (interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), leptin, adiponectin) and risk of premenopausal breast cancer among 453 cases and 453 matched, population-based controls from Chile, Colombia, Costa Rica, and Mexico. Odds ratios (OR) were estimated using conditional logistic regression models. Analyses were stratified by size and hormonal receptor status of the tumors. Results IL-6 (ORper standard deviation (SD) = 1.33 (1.11–1.60)) and TNF-α (ORper SD = 1.32 (1.11–1.58)) were positively associated with breast cancer risk in fully adjusted models. Evidence of heterogeneity by estrogen receptor (ER) status was observed for IL-8 (P-homogeneity = 0.05), with a positive association in ER-negative tumors only. IL-8 (P-homogeneity = 0.06) and TNF-α (P-homogeneity = 0.003) were positively associated with risk in the largest tumors, while for leptin (P-homogeneity = 0.003) a positive association was observed for the smallest tumors only. Conclusions The results of this study support the implication of chronic inflammation in breast cancer risk in young women in Latin America. Largest studies of prospective design are needed to confirm these findings in premenopausal women.

Objective. To assess whether the Catastrophic Health Expenditures Fund (FPGC, Spanish acronym) was associated with delays in seeking medical care and in starting treatment. Materials and methods. We conducted a before and after cross-sectional study. We included 266 women with breast cancer (BC) diagnosis treated during the last three years before the hospitals received the FPGC and 309 wo­men treated in the following three years after the fund was received by the accredited hospitals. Results. After adjusting for potential confounders, we found no association between the FPGC and delay in seeking medical care or between the FPGC and the treatment delay. Conclusions. The FPGC initiative reduced neither the delay in seeking breast cancer medical care for breast cancer nor the treatment delay.

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.

Abstract Background Thyroxine (T4) has been positively associated with tumor cell proliferation, while the effect of triiodothyronine (T3) on cell proliferation has not been well-established because it differs according to the type of cell line used. In Mexico, it has been reported that 14.5% of adult women have some type of thyroid dysfunction and abnormalities in thyroid function tests have been observed in a variety of non-thyroidal illnesses, including breast cancer (BC). These abnormalities might change with body mass index (BMI) because thyroid hormones are involved in the regulation of various metabolic pathways and probably by menopausal status because obesity has been negatively associated with BC in premenopausal women and has been positively associated with BC in postmenopausal women. Methods To assess the association between serum thyroid hormone concentration (T4 and T3) and BC and the influence of obesity as an effect modifier of this relationship in premenopausal and postmenopausal women, we measured serum thyroid hormone and thyroid antibody levels in 682 patients with incident breast cancer (cases) and 731 controls, who participated in a population-based case-control study performed from 2004 to 2007 in three states of Mexico. We tested the association of total T4 (TT4) and total T3 (TT3) stratifying by menopausal status and body mass index (BMI), and adjusted for other health and demographic risk factors using logistic regressions models. Results Higher serum total T4 (TT4) concentrations were associated with BC in both premenopausal (odds ratio (OR) per standard deviation = 5.98, 95% CI 3.01–11.90) and postmenopausal women (OR per standard deviation = 2.81, 95% CI 2.17–3.65). In premenopausal women, the effect of TT4 decreased as BMI increased while the opposite was observed in postmenopausal women. The significance of the effect modification was marginal (p = 0.059) in postmenopausal women and was not significant in premenopausal women (p = 0.22). Lower TT3 concentrations were associated with BC in both premenopausal and postmenopausal women and no effect modification was observed. Conclusions There is a strong association between BC and serum concentrations of TT3 and TT4; this needs to be further investigated to understand why it happens and how important it is to consider these alterations in treatment.

Objective. To compare trends in hospital discharges and mortality due to breast cancer (BC) in Mexico from 2004 to 2012 by insurance condition before and after incorporating BC comprehensive treatment into the System of Social Protection in Health (Sistema de Protrección Social en Salud, SPSS) in 2007. Materials and methods. Data on BC hospital discharges and mortality reported in women aged 25 years and over were obtained from the National Health Information System. Mortality rates were adjusted by age and state. Results. At the national level, a growing tendency in hospital discharges was observed, mainly for women without social security, while mortality rate remained constant. Mortality rates by state show that lower marginalization index corresponded to higher mortality. Conclusions. A differential behavior was observed among women according to insurance condition, partly due to the inclusion of BC treatment in the SPSS. DOI: http://dx.doi.org/10.21149/spm.v58i2.7788

Objective. To estimate the effect of care-delivery delays on survival among women with breast cancer. Materials and methods. A retrospective analysis of 854 women attending 11 hospitals from 2007-2009 was carried out. Kaplan-Meier estimators and a Cox proportional-risk model were employed. Results. A total of 10.5% of cases were diagnosed in stage I. 82% of sampled women delayed care for more than 67 days between noticing a symptom and initiating treatment. The median time from receipt of results of the mammography to biopsy was 31 days (IQR 14-56). Compared with those who were in quartile I (Q1), survival was lower among those in Q3 and Q4 (HR=1.68, 95%CI 0.94-3.00; HR=1.76, 95% CI 1.04-2.98, respectively). Conclusions. To increase survival, it is suggested that the time between receipt of the mammo- graphy results and diagnostic biopsy be reduced. DOI: http://dx.doi.org/10.21149/spm.v58i2.7793

Breast cancer is a major public health problem in Latin America (LA) and the most common form of cancer among women. An important variability according to ethnicity/race with respect to incidence/mortality, clinical characteristics, and prognosis is observed throughout LA. In addition, women are more likely to develop breast cancer (BC) at younger age and to be diagnosed at an advanced stage compared to western women. While little is known about specific risk factors, changes in reproductive pattern (parity, breastfeeding) and lifestyle factors including sedentary behaviours, unhealthy diet, and alcohol intake may contribute to the increase of BC incidence. In this paper we give an overview of the burden and patterns of BC, review the leading causes of BC and discuss the possible ways to improve BC prevention and control in LA.

OBJETIVO: Evaluar los factores pronósticos del cáncer de mama en mujeres mexicanas. MATERIAL Y MÉTODOS: Se incluyó a 432 mujeres con cáncer de mama admitidas de 1990 a 1999 en el Hospital General de México para evaluar la supervivencia mediante las técnicas de Kaplan-Meier y los métodos de riesgos proporcionales de Cox. RESULTADOS: La supervivencia global a cinco años fue de 58.9%. La menor supervivencia corresponde a los estadios clínicos IIIB (47.5%), IIIA (44.2%) y IV(15%), la metástasis hematógena fue de 21.4% y el tumor positivo en bordes quirúrgicos de 12.5%. La invasión linfovascular (RR= 1.9; IC95% 1.3-2.8), el estadio clínico IV (RR= 14.8; IC95% 5.5-39.7) y el tumor en bordes quirúrgicos (RR= 2.4; IC95% 1.2-4.8) fueron los principales factores pronósticos. CONCLUSIONES: Estos resultados dan consistencia a los criterios de diagnóstico y tratamiento de las mujeres con cáncer de mama atendidas en México y toman en consideración las condiciones de la tumoración, como extensión de la malformación, etapa clínica y estado de los ganglios linfáticos antes de decidir la conducta terapéutica inicial.OBJECTIVE: To evaluate prognostic factors for breast cancer in Mexican women. MATERIAL AND METHODS: Four hundred and thirty two women with breast cancer, admitted from 1990 to 1999 to the General Hospital of Mexico, were included to evaluate their survival using the Kaplan-Meier technique and Cox proportional hazard method. RESULTS: Overall 5-year survival was 58.9%. The shortest survival rate corresponds to the clinical stage (IIIB, 47.5%; IIIA, 44.2%; and IV, 15%), the haematological metastasis (21.4%) and surgical edges with positive tumor (12.5%). Lymph node-positive (RR, 1.9; IC95%, 1.3-2.8), clinical stage IV (RR, 14.8; IC95%, 5.5-39.7) and surgical edges with positive tumor (RR, 2.4; IC95%, 1.2-4.8) were the central prognostic factors. CONCLUSIONS: These results give consistency to diagnostic and therapeutic criteria for women with breast cancer who receive medical attention in Mexico, taking into consideration the characteristics of the tumor -such as extension, clinical stage and status of the lymph nodes- before making a decision as to the initial therapy.

La edad temprana de la menarca y tardía de la menopausia, la nuliparidad y la edad tardía de la madre en el primer embarazo se han relacionado con un incremento del riesgo de cáncer de mama (CaMa). Por el contrario, la paridad y el aumento del tiempo en meses de lactancia, en particular la que se ofrece al primer hijo, se han vinculado con un riesgo menor. La hipótesis de que la función ovárica, a través de sus hormonas, desempeña una función importante en el origen del cáncer de mama se ha sustentado en diversos estudios durante mucho tiempo. Aunque la mayor parte de los factores de riesgo relacionados con las características reproductivas es difícil de modificar, incrementar los meses de lactancia y evitar la exposición a los carcinógenos conocidos durante los periodos de desarrollo de la glándula mamaria son medidas para reducir el riesgo de esta enfermedad.Early age at menarche and late age at menopause, nulliparity, and late age at first pregnancy have been associated with an increased risk of BC. In contrast, parity and the increase in time breastfeeding, particularly during the first child have been associated with a decreased risk. The hypothesis that ovarian function, through their hormones, plays an important role in the etiology of breast cancer has been supported by various studies for a long time. Although most of the risk factors associated with reproductive characteristics are difficult to modify, to increase the breastfeeding time and to avoid exposure to known carcinogens during periods of development of the mammary gland are good strategies to reduce the risk of this disease.