Correlation of the Metabolic Syndrome with Estrogen Receptor Negative Breast Cancer in a Retrospective Review.

Abstract

Abstract Background: Obesity is a risk factor for breast cancer by increased peripheral estrogen aromatization. Obesity is one component of the metabolic syndrome. The relationship of the metabolic syndrome to breast cancer is unknown. The metabolic syndrome occurs more commonly among African American women and other ethnic groups with a relatively greater percentage of women at a lower socioeconomic status. We hypothesized that the occurrence of the metabolic syndrome may be associated with a more biologically aggressive cancer and may be a contributor to breast cancer disparities. One indicator of a more biologically aggressive disease is the absence of hormonal receptors. We proposed ER- breast cancer would be associated with more components of the metabolic syndrome than hormonally responsive breast cancer.Materials and Methods: 775 female breast cancer patients age 50 and over, diagnosed from 1999-2005, were identified through the Wake Forest University Tumor Registry. A retrospective chart review of the electronic medical records (EMR) was then performed to gather diagnoses of obesity, diabetes mellitus, dyslipidemias, and hypertension for 2 years from the date of their breast cancer diagnosis. We restricted our study to postmenopausal women to limit the impact of breast cancer treatment on the secondary health effects that may occur with therapy induced menopause. To assure we captured all the components of the metabolic syndrome that were not coded in the EMR, available blood pressures, heights, weights, medications and glucose and lipid measurements were queried for each woman.Results: 187 women were ER- and 588 were ER+. African American women were more likely to have ER- breast cancer (43% vs 21%, p < .001) and ER+ breast cancer patients were older than ER- patients (median age of 64 vs 60, p = .003.) From the available data among all studied women, 218 (28%) were obese, 554 (71%) were hypertensive, 197 (25%) were diabetic, 363 (47%) were dyslipidemic, and 198 women (26%) had 3 or more of the 4 metabolic diagnoses, giving them metabolic syndrome. Neither the metabolic syndrome nor its individual components were significantly associated with receptor status.Table 1. Association between estrogen receptor status and metabolic syndrome diagnosesCharacteristicER negativeER positivep value*Total187588 Median Age (Range)60 (50-90)64 (50-97).003Race <.001Black43 (23%)58 (10%) Hispanic1 (1%)1 (0%) Other1 (1%)2 (0%) White142 (76%)527 (90%) Obese .748No115 (69%)354 (68%) Yes51 (31%)167 (32%) Hypertension .373No42 (34%)114 (21%) Yes130 (76%)424 (79%) Diabetes .758No126 (72%)404 (73%) Yes49 (28%)148 (27%) Dyslipidemia .886No10 (10%)33 (11%) Yes88 (90%)275 (89%) Number of metabolic diagnoses .718 3 (3%)8 (3%) 114 (15%)38 (13%) 228 (30%)114 (39%) 328 (30%)84 (28%) 419 (21%)52 (18%) * Wilcoxon rank-sum test for age and chi-square tests for other variablesDiscussion: Although co-morbidities may contribute to breast cancer disparities, we did not find an association between the metabolic syndrome and more biologically aggressive breast cancer as represented by ER- disease. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2061.