A recent study showed that black women with endometrial cancer are less likely than their white counterparts to receive evidence-based care, according to findings released by the Society of Gynecologic Oncology (Abstract 146). The researchers also found that, while receiving evidence-based care can help mitigate racial disparities in outcomes, it does not eliminate them. Black women remain at a higher risk of death from endometrial cancer.
"There is long-standing evidence that black women with endometrial cancer experience worse outcomes than white women. Compared to white women, black women with endometrial cancer experience up to 80 percent increased risk of death," noted study author Allan Huang, BSc, of Columbia University. "Despite the eye-opening magnitude of this disparity and the accumulating research examining why it exists, in the past years, the disparity has persisted unchanged.
"Based on prior research, we know that several factors may contribute to racial gaps in outcomes. Black women tend to have more aggressive forms of endometrial cancer, are more likely to experience lower socioeconomic status, and are less likely to receive standard-of-care treatments," he continued. "With our study, we asked whether black women who received the same quality of care as white women would continue to experience worse outcomes."
Study Methodology & Results
The researchers utilized the National Cancer Database to identify women with endometrial cancer treated from 2004 to 2016.
Five evidence-based quality metrics were developed, which included surgical treatment within 6 weeks of diagnosis, use of minimally invasive surgery (stage I-IIIC), pelvic nodal assessment (high-risk tumors), adjuvant radiation (high intermediate risk), and systemic chemotherapy (stage III-IV).
"Neatly encapsulating the standard of care for endometrial cancer in five treatment metrics was certainly a complex task and required close review of the relevant oncology society guidelines and trials," Huang explained. "An example includes establishing an adjuvant radiation therapy metric. We initially considered only vaginal brachytherapy as standard of care, but later widened the metric to include all forms of adjuvant pelvic radiotherapy in an attempt to capture a wider variety of treatment styles."
Huang and his team compared rates of 30-day and 90-day mortality as well as 5-year among black and white women. "To determine the influence of quality on outcomes, we compared outcomes among perfectly adherent black and white women with stage I and III endometrial cancer," according to the study authors.
The researchers identified 310,208 women with endometrial cancer, including 35,035 (11.3%) black women and 275,173 (88.3%) white women. Data showed that black women were less likely than white women to receive surgical treatment within 6 weeks of diagnosis (65.8% vs. 75.6%), use of minimally invasive surgery (58.5% vs. 72.9%), pelvic nodal assessment (71.3% vs. 74.2%), and systemic chemotherapy (72.7% vs. 73.2%), according to the study authors.
"Utilizing a broad body of literature, we established five key treatment criteria that represent the standard of care for endometrial cancer. With these criteria, we selected a group of black and white women from the National Cancer Database who had received care that was entirely adherent to treatment guidelines and compared their outcomes," Huang explained. "Broadly, the black and white women in this group could be considered to have received equal quality of care."
The study authors reported that adherence to each quality metric was associated with improved survival. Among women with stage I endometrial cancer, perfect adherence to the relative quality metrics was seen in 53.1 percent of white and 41.5 percent of black women. In women with stage III disease, perfect adherence was reported in 56.6 percent of white and 44.1 percent of black women.
"Unsurprisingly, we found that black women were 16 percent less likely to receive standard-of-care treatment compared to white women," Huang told Oncology Times. "However, receipt of standard-of-care treatment was associated with improved long- and short-term survival outcomes in both black and white women.
"Among women with stage I cancer who received perfectly adherent care, black women still experienced 125 percent, 84 percent, and 42 percent increased risk of death at 30 days, 90 days, and 5 years, respectively from initial diagnosis of their cancer," he continued. "Similarly, despite equal, quality care, black women with stage III cancer continue to experience 86 percent and 35 percent increased risk of death at 30 days and 5 years, respectively, compared to similar white women."
Clinical Significance & Next Steps
These results demonstrate that receipt of guideline-adherent care does not eliminate racial disparities in endometrial cancer outcomes in black women compared to white women, according to Huang.
"However," he noted, "women who received adherent care experienced improved outcomes compared to the general cohort of all women, regardless of race. These results point to the presence of hidden factors contributing to disparities. One possibility is a synergistic effect between aggressive tumor biology and lower socioeconomic status, which would be uncaptured by our analyses.
"What is clear is that guideline-adherent care improves outcomes for all, and while this may seem self-evident, large gaps in the delivery of such care continue to exist," Huang emphasized. "Such gaps in care delivery should be the focus of future investigation."
The next steps, Huang noted, include investigating the root causes that underlie unequal delivery of care in endometrial cancer between black and white patients.
"Disparities in care arise anywhere in the treatment process. Biases in physician decision-making, suboptimal delivery of care, or barriers to accessing care like insurance status, transportation, or dearth of social support undoubtedly all play a role," he said. "Dissecting the relative contributions of these factors and developing focused interventions to address them have the greatest potential to improve outcomes for all women."
Huang emphasized that this is an issue that goes beyond endometrial cancer. "While our study focused on racial disparities in endometrial cancer treatment, it is important to acknowledge that black patients receive inferior care in other gynecologic and non-gynecologic malignancies, including advanced breast cancer, lung cancer, and prostate cancer," he concluded. "For example, a study using the same database we used found that black patients were 24 percent less likely to receive preoperative chemotherapy for gastric cancer."
Catlin Nalley is a contributing writer.