Comparative study of breast cancer in Mexican and Mexican-American women

Abstract

Breast cancer is the number one cause of can- cer deaths among Hispanic women in the United States, and in Mexico, it recently became the primary cause of cancer deaths. This malign- nancy represents a poorly understood and un- derstudied disease in Hispanic women. The ELLA Binational Breast Cancer Study was es- tablished in 2006 as a multi-center study to as- sess patterns of breast tumor markers, clinical characteristics, and their risk factors in women of Mexican descent. We describe the design and implementation of the ELLA Study and provide a risk factor comparison between women in the U.S. and those in Mexico based on a sample of 765 patients (364 in the U.S. and 401 in Mexico). Compared to women in Mexico, U.S. women had significantly (p < 0.05) lower parity (3.2 vs. 3.9 mean live births) and breastfeeding rates (57.5% vs. 80.5%), higher use of oral contraceptives (60.7% vs. 50.1%) and hormone replacement therapy (23.3% vs. 7.6%), and higher family history of breast cancer (15.7% vs. 9.0%). Re- sults show that differences in breast cancer risk factor patterns exist between Mexico and U.S. women. We provide lessons learned from the conduct of our study. Binational studies are an important step in understanding disease pat- terns and etiology for women in both countries

Association between polymorphisms in the thymidylate synthase gene and risk of breast cancer in a Mexican population

“…The Ella Study is a case-control study that includes women of Mexican descent in the United States and Mexico, and has been described previously (Martínez et al, 2010). In this study, we only included patients from the State of Jalisco, Mexico.…”

Reproductive and Hormonal Risk Profile According to Language Acculturation and Country of Residence in the Ella Binational Breast Cancer Study

“…Rather, our study provides a framework for an analytical approach for use in binational studies. However, given that we have adequate annotation of the tumor marker profiles 25,31 we will be able to assess the role of reproductive and hormonal factors in relation to breast tumor subtypes in the context of acculturation in future studies.…”

“…Furthermore, by including only women of Mexican descent in our study, we are able to exclude heterogeneity that is present in some studies of Hispanics in the US, which assume the existence of a homogeneous culture across all sub-groups. Our clinic-based study was completed with very high response rates ( > 90%) 25 minimizing sampling bias. As noted previously, adjustment for education is also a strength of our analytical approach.…”

“…All recruitment sites used a predominantly clinic-based recruitment strategy; response rates for all aspects of the study (i.e., risk factor questionnaire, medical record access, and tissue collection) ranged from 95%-99%. 25 The dataset for the present analyses includes women who provided risk factor questionnaire and medical record data and who have known data on acculturation, education, and age at diagnosis (n = 1201). The Institutional Review Board from each institution approved the study, and all participants provided written informed consent.…”

“…25 Briefly, the Ella Study is a case series of women of self-reported Mexican descent who were age ‡ 18 years and diagnosed with invasive breast cancer in the previous 24 months prior to enrollment. Participants were recruited from two study sites in the US (University of Arizona in Tucson, Arizona and MD Anderson Cancer Center in Houston, Texas) and three sites in Mexico (Universidad de Sonora in Hermosillo, Sonora; Instituto Tecnológico de Sonora in Ciudad Obregon, Sonora; and Universidad de Guadalajara in Guadalajara, Jalisco).…”