Endometrial Cancer on the Rise and Impacts Black Women the Most

Michele L. Cote, PhD

Michele L. Cote, PhD

Rates of endometrial cancer continue to increase among all racial and ethnic groups, but they’re rising faster among non-Hispanic black women who also have poorer outcomes when compared with their white, non-Hispanic counterparts, a new study has found.

Endometrial cancer is the most commonly diagnosed gynecologic cancer in the United States, and incidence rates have been rising for many years, according to the study’s lead author Michele L. Cote, PhD. Cote, an associate professor of oncology at the Barbara Ann Karmanos Cancer Institute and Wayne State University School of Medicine in Detroit, said that her research team launched this study to find out whether this increasing incidence and mortality are equally distributed by race/ethnicity and endometrial cancer subtype.

The answer, they found, is no.

“The most significant finding was that non-Hispanic black women had poorer outcomes compared with non-Hispanic white women diagnosed with the same subtype of endometrial cancer and at the same stage of disease, while Hispanic and Asian women had similar or better outcomes compared with their non-Hispanic white counterparts,” said Cote in a statement.

“Prior studies have suggested that disparities in outcomes from endometrial cancer might be explained by differences in tumor subtype or stage at diagnosis, but our data suggest that disparities persist even when these factors are controlled for.”

The researchers analyzed endometrial cancer incidence and mortality data from the SEER database, based on 120,513 cases of the disease diagnosed from 2000-2011.

Over the 12 years studied, endometrial cancer incidence rates increased fastest, at 2.5% per year, among non-Hispanic black women and Asian women. But for non-Hispanic black women their rates of all the aggressive endometrial cancer subtypes (eg, clear cell, serous, high-grade endometriod, and malignant mixed Mullerian tumors) were 1.5-fold higher than those for non-Hispanic white, Asian, and Hispanic women.

Analysis of overall 5-year survival rates showed that non-Hispanic black women had poorer survival at every stage of diagnosis, regardless of endometrial cancer subtype, compared with non-Hispanic white women, whereas 5-year survival rates were similar or higher among Asian and Hispanic women compared with non-Hispanic white women.

Cote acknowledged a limitation of the study is that the data analyzed were from the SEER database, which meant the researchers did not have tumor samples and were unable to perform a review of the tumor subtype to ensure they had been classified correctly. In addition, SEER does not collect information on other factors that may be associated with incidence and survival; thus, potential causes for the disparities identified in this study cannot be further examined.

Nevertheless, said Cote, “It was somewhat surprising that the endometrial cancer survival disparity we identified was limited to non-Hispanic black women because many of the challenges previously linked to worse outcomes, including low socioeconomic status and high rates of obesity and diabetes, are also experienced by Hispanic women, but that population did not have poor outcomes,” said Cote.

“We are, therefore, interested in investigating whether there are molecular differences in endometrial tumors of the same subtype from women of different races or ethnicities diagnosed at the same stage of disease.”

Cote ML, Ruterbusch JJ, Olson SH, et al. The growing burden of endometrial cancer: a major racial disparity affecting black women [published online ahead of print August 19, 2015]. Cancer Epidemiol Biomarkers Prev.