Association between parity and obesity in Mexican and Mexican-American women: Findings from the ella binational breast cancer study

Obesity at diagnosis of breast cancer is associated with higher all-cause mortality and treatment-associated toxicities. We evaluated the association between parity and obesity in the Ella study, a population of Mexican and Mexican-American breast cancer patients with high parity. Obesity outcomes included body mass index (BMI) ?30 kg/m2, waist circumference (WC) ?35 in (88 cm), and waist-to-hip-ratio (WHR) ?0.85. Prevalence of obesity ([BMI] ? 30 kg/m2) was 38.9 %. For WC, the multivariate odds ratio (OR) (95 % confidence interval [CI]) for having WC ? 35 inches in women with ?4 pregnancies relative to those with 1-2 pregnancies was 1.59 (1.01-2.47). Higher parity (?4 pregnancies) was non-significantly associated with high BMI (OR = 1.10; 95 % CI 0.73-1.67). No positive association was observed for WHR. Our results suggest WC is independently associated with high parity in Hispanic women and may be an optimal target for post-partum weight loss interventions. © 2012 Springer Science+Business Media, LLC

Reproductive and hormonal risk profile according to language acculturation and country of residence in the ella binational breast cancer study

Background: We compared the distribution of breast cancer reproductive and hormonal risk factors by level of acculturation and country of residence in women of Mexican descent. Methods: To compare the distribution of breast cancer reproductive and hormonal risk factors by level of acculturation and country of residence in women of Mexican descent, taking into account level of education, we analyzed data on 581 Mexican and 620 Mexican American (MA) women with a history of invasive breast cancer from the Ella Binational Breast Cancer Study. An eight-item language-based acculturation measure was used to classify MA women. Multivariate logistic regression was used to test associations between language acculturation, country of residence, and reproductive and hormonal risk factors. Results: After adjustment for age and education, compared to women residing in Mexico, English-dominant MAs were significantly more likely to have an earlier age at menarche (<12 years; odds ratio [OR]=2.08; 95% confidence interval [CI], 1.30-3.34), less likely to have a late age at first birth (?30 years; OR=0.49; 95% CI, 0.25-0.97), and less likely to ever breastfeed (OR=0.13; 95% CI, 0.08-0.21). Conclusions: Differences in reproductive and hormonal risk profile according to language acculturation and country of residence are evident; some of these were explained by education. Results support continued efforts to educate Mexican and MA women on screening and early detection of breast cancer along with promotion of modifiable factors, such as breastfeeding. © Mary Ann Liebert, Inc

Hypothesized role of pregnancy hormones on HER2+ breast tumor development

Breast cancer incidence rates have declined among older but not younger women; the latter are more likely to be diagnosed with breast cancers carrying a poor prognosis. Epidemiological evidence supports an increase in breast cancer incidence following pregnancy with risk elevated as much as 10 years post-partum. We investigated the association between years since last full-term pregnancy at the time of diagnosis (?10 or >10 years) and breast tumor subtype in a case series of premenopausal Hispanic women (n = 627). Participants were recruited in the United States, Mexico, and Spain. Cases with known estrogen receptor (ER), progesterone receptor (PR), and HER2 status, with one or more full-term pregnancies ?1 year prior to diagnosis were eligible for this analysis. Cases were classified into three tumor subtypes according to hormone receptor (HR+ = ER+ and/or PR+; HR- = ER- and PR-) expression and HER2 status: HR+/HER2-, HER2+ (regardless of HR), and triple negative breast cancer. Case-only odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated for HER2+ tumors in reference to HR+/HER2- tumors. Participants were pooled in a mixed-effects logistic regression model with years since pregnancy as a fixed effect and study site as a random effect. When compared to HR+/HER2- cases, women with HER2+ tumors were more likely be diagnosed in the post-partum period of ?10 years (OR = 1.68; 95 % CI, 1.12-2.52). The effect was present across all source populations and independent of the HR status of the HER2+ tumor. Adjusting for age at diagnosis (?45 or >45 years) did not materially alter our results (OR = 1.78; 95 % CI, 1.08-2.93). These findings support the novel hypothesis that factors associated with the post-partum breast, possibly hormonal, are involved in the development of HER2+ tumors. © 2012 Springer Science+Business Media New York

Genomic Disparities in Breast Cancer among Latinas

BACKGROUND: Breast cancer is the most common cancer diagnosed among Latinas in the United States and the leading cause of cancer-related death among this population. Latinas tend to be diagnosed at a later stage and have worse prognostic features than their non-Hispanic white counterparts. Genetic and genomic factors may contribute to observed breast cancer health disparities in Latinas. METHODS: We provide a landscape of our current understanding and the existing gaps that need to be filled across the cancer prevention and control continuum. RESULTS: We summarize available data on mutations in high and moderate penetrance genes for inherited risk of breast cancer and the associated literature on disparities in awareness of and uptake of genetic counseling and testing in Latina populations. We also discuss common genetic polymorphisms and risk of breast cancer in Latinas. In the treatment setting, we examine tumor genomics and pharmacogenomics in Latina patients with breast cancer. CONCLUSIONS: As the US population continues to diversify, extending genetic and genomic research into this underserved and understudied population is critical. By understanding the risk of breast cancer among ethnically diverse populations, we will be better positioned to make treatment advancements for earlier stages of cancer, identify more effective and ideally less toxic treatment regimens, and increase rates of survival