Women in the United States are less likely to die of ovarian cancer, but more likely to die of endometrial cancer than they were 3 decades ago, according to a recent research letter published in Obstetrics & Gynecology.
“This convergence is because of a steady reduction in the death rate for ovarian cancer, partly because of advances in treatment, alongside a steep increase in the death rate for endometrial cancer,” Rebecca L. Siegel, MPH, corresponding author and senior scientific director of surveillance research at the American Cancer Society, said in an interview. “Endometrial cancer has not had any major treatment advances in 40 years.”
Rebecca Siegel
However, Ms. Siegel and colleagues also found Black women had a twofold higher endometrial cancer–related mortality rate over the same time frame, compared with White women. The disparity in endometrial cancer mortality rates for Black women compared with White women is alarming, the authors said, and might be an underestimate because of a higher rate of hysterectomy among Black women.
The researchers analyzed endometrial and ovarian cancer mortality rates from the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (SEER) with the SEER*Stat software, stratifying the data by whether the person belonged to mutually exclusive racial and ethnic categories of White, Asian or Pacific Islander, Black, or Hispanic. They identified 232,957 women who died from endometrial cancer and 419,085 people who died from ovarian cancer between 1990 and 2019.
Ms. Siegel and colleagues found there was a decrease in ovarian cancer mortality rates between 1990 (9.3 per 100,000 women) and 2019 (6.0 per 100,000 women) (average annual percent change, 22.7%; 95% confidence interval, 23.5%-22.0%). While endometrial cancer mortality decreased between 1990 (4.3 per 100,000 women) and 1997 (4.0 per 100,000 women), it increased between 1997 and 2019 (5.1 per 100,000 women) (average annual percent change, 1.7%; 95% CI, 1.3%-2.1%). When measuring ovarian cancer mortality to endometrial cancer mortality from 1990 (9.3 vs. 4.3 per 100,000), compared with 2019 (6.0 vs. 5.1 per 100,000), there is a significant decline in excess deaths from ovarian cancer.
“Three decades ago, women in the United States were almost twice as likely to die from ovarian cancer as they were to die from endometrial cancer,” Ms. Siegel said in an interview. “Today the difference is only 15% higher, or an excess of less than 1 death per of 100,000 women.”
Growing racial disparity in endometrial cancer mortality
While these results persisted for some racial and ethnic subgroups, it did not persist for Black women, who saw an increase in endometrial cancer mortality rate from 7.2 per 100,000 women between 1990 and 1994 to 9.1 per 100,000 women between 2015 and 2019. Compared with White women, there was a significant increase in the mortality rate ratio for uterine cancer for Black women, from 1.83 between 1990 and 1994 (95% CI, 1.77-1.89) to 1.98 between 2015 and 2019 (95% CI, 1.93-2.02) (P < .001).
“Endometrial cancer has one of the largest racial disparities of any cancer. The 5-year relative survival rate for Black women is 63% compared to 84% for White women – a 21% gap in absolute terms. This is largely due to less access to high-quality health care, which is reflected in both later-stage diagnosis and lower survival for every stage of disease,” Ms. Siegel said in an interview. Other factors that contribute include lack of guideline-concordant surgical treatment, and increased risk of aggressive tumor subtypes.
Dr. Alex Francoeur
Alex A. Francoeur, MD; and Ritu Salani, MD, MBA, of the department of obstetrics and gynecology at the University of California, Los Angeles, who were not involved in the study, said the research by Ms. Siegel and colleagues “highlights growing disparities in uterine cancer between non-Hispanic Black and non-Hispanic White women.”
“Understanding race as a social, not biological construct, and as a proxy for socioeconomic status, is key to understanding this disparity,” said Dr. Francoeur, a third-year ob.gyn. resident at UCLA Health, and Dr. Salani, an Ob.Gyn. News editorial board member. “For example, many studies cite a more advanced stage at diagnosis as an explanation for racial disparities in endometrial cancer; however, this is a substitute for differences in health care access as well as other socioeconomic factors such as income and education.”
Dr. Francoeur and Dr. Salani also acknowledged other disparities in risk factors may play a role in the differences in endometrial mortality rates such as obesity, which “in non-Hispanic Black women is over 60% greater than non-Hispanic White women.”
Dr. Ritu Salani
In terms of limitations, they noted that SEER’s database is less representative of the population, compared with the United States Cancer Statistics database (36.7% vs. 99%), and that factors such as greater prevalence of hysterectomy may contribute to larger racial disparities.
“Future studies need to examine inequities in treatment by race as well as the importance of health care systems in the stage of diagnosis,” they said.
Ms. Siegel said her team plans to follow the patterns outlined in this analysis and examine factors like cancer subtype, socioeconomic status, and place of residence in the future. “However, health inequalities are rooted in systemic racism, so documentation is necessary but insufficient to effect change, which must occur at the institutional level. A more concerted effort is needed to ensure that every woman receives appropriate treatment, regardless of the color of her skin, and education of providers to reduce racial bias and help increase trust in the health care system should be required.”
The authors reported no relevant financial disclosures. Dr. Francoeur and Dr. Salani reported no relevant financial disclosures.