Obesity, Hormone Receptor Status, and Breast Cancer Occurrence and Survival in New Mexico Hispanic and Non-Hispanic White Women

摘要

In New Mexico, over the past 30 years, breast cancer incidence rates among Hispanic women have doubled, and mortality rates have increased over 50%. The factors responsible for these trends are not currently understood. This post-doctoral training project was designed to: 1) investigate ethnic differences in the prevalence, and the timing of the development of obesity in relation to breast cancer risk. 2) to determine whether ethnic differences in body composition and tumor hormone receptor status contribute to breast cancer survival among New Mexico women. Analyses completed in Year 3 utilized data from the 1996-1999 New Mexico HEAL study (n=650 total cases. 498 invasive cases). Over-all survival (estimated from 1648 person-years of follow-up) was reduced among Hispanic (H) women compared to Non-Hispanic white (NHW) women (H 85% vs. 91.5% NHW), and the percentage of deaths due to breast cancer was higher (11% H vs. 4% NHW, P< 8.887). Body mass index was not significantly associated with breast cancer survival. However. the risk of developing breast cancer (determined from the 1992-94 New Mexico Womens' Health Study case-control data set) was 2.4 (95% CI 1%4-4.8) for Hispanic women whose adult wt. gain was >38 lbs. Significant factors associated with breast cancer death included ER negative status (3.1; 95% CI 1.3-7.4) and stage at diagnosis (TNM Stage IIB vs. Stage I, 3.8; 95% CI 1.3-18.8). After adjusting for age, menopausal status, tamoxifen, stage, and ER status, Hispanic women's risk of breast cancer death was twice that of NHW (2.8: 95% CI .9-4.2, p<.87). Future research with this cohort is warranted in order to identify additional factors that contribute to the ethnic disparity in breast cancer survival.