ReviewDisparities in uterine cancer epidemiology, treatment, and survival among African Americans in the United States
Introduction
African Americans fare worse than whites across a spectrum of diseases, including diabetes, heart disease, and various malignancies. Gynecologic cancers are not immune to this phenomenon [1]. Endometrial cancer exhibits particularly striking racial differences. Despite a 30% decreased incidence among African Americans, those who are diagnosed with endometrial cancer are 2.5 times more likely to die than their Caucasian counterparts [2]. Though the explanation for this is likely multi-factorial, histopathologic disparities, with aggressive subtypes more common in African Americans, and socioeconomic differences, causing decreased access to healthcare among minority patients, are often assigned the largest roles. Other studies have examined molecular and genetic alterations, increased prevalence of comorbidities, and inconsistencies in treatment patterns among different races in an attempt to explain the inequalities. The purpose of this review is to examine the current literature in order to identify clinical, biological, and socioeconomic areas where disparities exist and identify ways to address these inequalities. Forty-two studies were initially identified, and 24 were reviewed after exclusion of studies that did not specifically address the disparities between African Americans and Caucasians with endometrial cancer. The reviewed studies had a total of 366,299 cases of endometrial cancer (337,597 Caucasian and 28,702 African American) (Table 1).
Section snippets
Incidence
Though African American women have a 7% lower incidence rate of all cancers when compared to white women, their overall cancer-related death rate is 17% higher. This discrepancy is seen in a variety of cancers including breast cancer and colorectal cancer [3], [4]. In endometrial cancer, the disparity is considerably more pronounced. The incidence in African Americans is 30% lower and the mortality rate 80% higher when compared to whites [1]. Fig. 1 shows the trend in incidence and mortality of
Histopathologic factors and stage at presentation
Five population-based studies and one large single-institution study documented the racial disparity in endometrial cancer histology and stage at presentation (Table 2, Table 3) [6], [7], [9], [11], [12], [13]. Though only one of these studies was a prospective analysis [7], all utilized large sample populations and reported similar rates of each cancer subtype across ethnic groups. They showed that African American patients are less likely than Caucasians to present with endometrioid histology
Molecular and genetic factors
African American women present with more aggressive subtypes of endometrial cancer and at more advanced stage compared to Caucasians. The increased incidence of serous and clear cell tumors and sarcomas accounts, at least in part, for more disseminated disease at presentation. Endometrioid endometrial cancer has a distinct genetic profile when compared to type II endometrial cancers. Racial differences in molecular and genetic factors may explain the histologic and survival discrepancy.
Socioeconomic factors
Biologic factors do not solely explain the survival disparity seen in endometrial cancer, as African American death rates remain higher at every stage, type, and grade of disease [2]. African Americans are more likely than Caucasians to live in poverty and reside in underserved areas. They are less likely to receive higher education, to possess private health insurance, and to have regular primary healthcare. Studies have found no difference in time from bleeding onset to consultation or
Comorbid factors
African Americans have higher rates of obesity, hypertension, diabetes, and heart disease and have worse health outcomes compared to other races in the United States. Some have argued that these comorbidities could explain the disparities found in this population, especially as these conditions also serve as risk factors for endometrial cancer.
In the Multiethnic Cohort Study of 46,933 women, Setiawan et al. found that endometrial cancer was positively associated with later age at menopause,
Treatment factors
Treatment factors have been suggested as a reason for the mortality disparity among African American women with endometrial cancer. Recent studies have examined the rates of definitive surgery and appropriate treatment for various ethnic groups. In an analysis of data from the National Cancer Database from 1988 to 1994, Hicks et al. found that African American women were less likely to undergo definitive surgery at every stage of disease. Even for stage I disease, 7.7% of African American women
Conclusion and recommendations
The survival disparity in African American women with endometrial cancer is multifactorial, and its complexity highlights the need for continued research in this area. Despite having a lower incidence of endometrial cancer, African American women have almost twice the disease-specific mortality rate [38]. Our analysis suggests that histopathologic factors play the largest role in the disparity, with African Americans experiencing higher rates of aggressive histologic subtypes, poorly
Conflict of interest statement
The authors have no conflicts of interest or financial relationships to disclose.
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