ABSTRACT
BACKGROUND: African American (AA) women are known to have poorer breast cancer survival than whites, and the differences may be related to underlying disparities in their clinical presentation or access to care. This study evaluated the relationship between demographic, treatment, and socioeconomic factors and breast cancer survival among women in southeast Michigan. METHODS: The population included 2387 women (34% AA) with American Joint Committee on Cancer stage I to III breast cancer who were treated at the Henry Ford Health System (HFHS) from 1996 through 2005. Linked data sets from the HFHS, the Metropolitan Detroit Cancer Surveillance System, and the US Census Bureau were used to obtain demographic and clinical information. Comorbidities were classified with the modified Charlson comorbidity index (CCI). Economic deprivation was categorized with a census tract-based deprivation index (DI), which was stratified into 5 quintiles of increasing socioeconomic disadvantage. RESULTS: Compared with whites, AA women were significantly more likely to have larger, hormone receptor-negative tumors and more comorbidities and to reside in an economically deprived area. In an unadjusted analysis, AAs had a significantly higher risk of death (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.16-1.59); however, after adjustments for clinical (age, stage, hormone receptor, and CCI) and societal factors (DI), the effect of race was not significant (HR, 1.13 [95% CI, 0.96-1.34] , and HR, 0.97 [0.80-1.19] respectively). CONCLUSIONS: Racial differences in breast cancer survival can be explained by clinical and socioeconomic factors. Nonetheless, AA women with breast cancer remain disproportionately affected by unfavorable tumor characteristics and economic deprivation, which likely contribute to their increased overall mortality.
Subject(s)
Breast Neoplasms/ethnology , Breast Neoplasms/mortality , Health Services Accessibility/economics , Black or African American/statistics & numerical data , Breast Neoplasms/economics , Breast Neoplasms/pathology , Delivery of Health Care, Integrated , Female , Humans , Michigan/epidemiology , Michigan/ethnology , Risk Assessment , Socioeconomic Factors , Survival Rate/trends , Urban Health Services , White People/statistics & numerical dataABSTRACT
An increased risk of breast cancer has been reported in patients with non-melanomatous skin cancer (NMSC), but this association has not been studied in a large, multi-geographic population. We utilized data from the Women's Health Initiative observational study to assess whether history of NMSC is associated with breast cancer risk. This analysis included 70,246 postmenopausal White and Hispanic women aged 50-79, in which 4,247 breast cancer cases were identified over a mean (SD) of 11.3 (3.2) years. Baseline information was collected on demographics, medical history, sun exposure, and vitamin D intake. Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95 % confidence intervals (CIs). The relationship between NMSC and breast cancer was examined as a time-dependent exposure using updated information on NMSC gathered during follow-up visits. All statistical tests were two sided. There were 5,595 women diagnosed with NMSC at study entry. The annualized rate of breast cancer was 0.64 % among women with a history of NMSC and 0.55 % among women with no history of NMSC. The multivariable-adjusted HR for breast cancer among women with a history of NMSC versus no history of NMSC was 1.07 (95 % CI 0.95-1.20, P = 0.27). Further evaluation stratified by tumor characteristics showed an increased risk of lymph node-positive disease, HR = 1.30 (95 % CI 1.01-1.67, P = 0.04), and regional-stage disease, HR = 1.33 (95 % CI 1.05-1.70, P = 0.02), among women with NMSC. There was no significant overall association between NMSC and breast cancer; however, there was an increased risk of more advanced-stage breast cancer which needs further exploration.