Black, Hispanic Patients Underrepresented in Clinical Trials Cited in NCCN Guidelines for Endometrial Cancer Systemic Therapy Regimens

Although poorer prognoses are common for all patients with advanced and recurrent endometrial cancers, minority populations are disproportionately affected with higher rates of mortality.

Although endometrial cancer is commonly detected early and can be effectively treated with surgery, case rates for the disease are currently rising. With this increase, patients whose disease is not detected early and who have high-risk advanced and recurrent endometrial cancers have poorer prognoses and require adjuvant therapy, according to a presentation by Amita Kulkarni, MD, at the Society of Gynecologic Oncology annual meeting.

Kulkarni noted that although poorer prognoses are common for all patients with advanced and recurrent endometrial cancers, minority populations are disproportionately affected with higher rates of mortality. Additionally, racial disparities are further compounded by socioeconomic status, access to quality care, insurance status, and systemic racism.

“Racial and ethnic minority populations are disproportionately impacted, often presenting with more aggressive non endometrioid histologies and molecular alterations, advanced stage disease, and higher rates of recurrence. Specifically, our Black patients have mortality rates twice that of the rates of White women,” Kulkarni said. “Our Hispanic patients often present at younger ages with more advanced stage disease and are less likely to receive guideline accordant care.”

Clinical trial data can help to inform standard of care treatment guidelines for gynecologic cancers, with representation of patients at the highest risk of poorer health outcomes in clinical trial populations remaining essential to understanding their real-world outcomes. However, these populations are historically underrepresented in clinical trials that look to assess these outcomes, which can in turn impact the standards for care.

Because of this historical tendency, Kulkarni noted a need to assess how race and ethnicity are represented within publications that were selected by the National Comprehensive Cancer Network (NCCN) as high-quality evidence for the preferred systemic treatment regimens for endometrial cancer, with a specific look toward race and ethnicity distribution among clinical trial participants.

To accomplish this, Kulkarni and her colleagues looked at the list of citations for systemic therapies for endometrial cancer references in the “NCCN Clinical Practice Guidelines: Uterine Neoplasms 4.2021.” Race and ethnicity data were then manually abstracted and pooled among studies reporting these data. Using the CDC’s US Cancer Statistics Database (1997-2017), they then compared the distribution of race and ethnicity in these studies with that of the national database.

Among the 10 eligible studies, Kulkarni noted that only 4 reported on race and ethnicity. However, 1 of these 4 studies did not specify the race and ethnicity of the 13 enrolled patients with endometrial cancer, so it was subsequently excluded from the review.

Upon analysis of the data from the 3 eligible studies, Kulkarni explained there was heterogeneity in how race and ethnicity were presented in each. For example, one study included race but not ethnicity, with the categories under race including White, Black, and Other. The other 2 studies also varied widely in how they reported race categories, although ethnicity for both was listed as being an option between Hispanic or Non-Hispanic.

Ultimately, the 3 eligible studies that reported on race and ethnicity included 663 patients in total. These studies evaluated the role of trastuzumab in HER2-positive uterine serous carcinomas, with adjuvant radiotherapy followed by chemotherapy in combination with immunotherapy, respectively.

In the data presented in these 3 studies, 49 patients (7.4%) self-identified as Black; however, in the 2 studies that reported on ethnicity, 18 patients (3.0%) self-identified as Hispanic. Compared with the Black patients that made up 7.4% of the clinical trials, the data available in the CDC’s US Cancer Statistics Database showed that from 1997 to 2017, the percentage of Black patients with endometrial cancer was 10% of total patients, according to Kulkarni.

She further explained that when her team looked at the data comparison for Hispanic patients, who made up 3% of trial participants in the NCCN’s referenced clinical studies, they found that approximately 7.6% of US incidence of endometrial cancer cases were among Hispanic patients between 1997 and 2017.

“In our review of the cited NCCN recommendations for systemic therapy for endometrial cancer, less than half of the reported studies included race and ethnicity information. Those studies that did include this information provided the categories in variable ways. We recognize the limitations in collecting race and ethnicity information, as well as the small sample sizes of a number of the cited references, some of which were interim analyses,” Kulkarni said.

Although 7 studies examined targeted therapy regimens for advanced and recurrent disease, only 2 reported on the racial and ethnic backgrounds of the patient populations, making it challenging to apply these findings to the most diverse, high-risk patients, Kulkarni explained. Of the 3 studies that did include race and ethnicity information of included patients, there were no available subgroup analyses examining the therapeutic affects by race and ethnicity.

“We recognize that this is not always feasible with small sample sizes, but information like this may be helpful in the future,” Kulkarni said.

In summary, Kulkarni explained that the data analysis her team conducted showed that Black and Hispanic patients were often underrepresented in individual clinical trials cited in the NCCN’s recommendations for systemic therapy for endometrial cancer, which is used as a standard in the field that is expected to inform clinical care for this disease.

“Moving forward, we must continue to do more to prioritize minority patient recruitment, as well as transparency with reporting on race and ethnicity information in therapeutic trials,” Kulkarni said. “This will help to ensure that the treatment guidelines that are developed based on these clinical studies accurately reflect and translate to our diverse, real-world patient populations. While there is much work to be done, these are just some ways to address racial disparities and improve the quality of endometrial cancer care.”

REFERENCE

Kulkarni A. Scientific Plenary I: Breaking Barriers: Towards Greater Equity in Gyn Oncology Care. Society of Gynecologic Oncology 2022; March 18, 2022; Phoenix, AZ.