Race, Ethnicity ‘Notably Underreported’ in Publicly Accessible Databases of Gynecologic Cancer Trials

Findings from a recent 30-year analysis of more than 1,000 gynecologic cancer trials strongly suggest that reporting race and ethnicity must be a required part of clinical research to improve diversity, according to a group of researchers.

From 1988 to 2019, clinical trials in gynecologic malignancies rarely reported the race and ethnicity of patients, according to findings from an analysis published in Cancer Causes & Control.

Investigators wrote that this paucity of data hampers efforts toward greater diversity in oncologic research.

The analysis evaluated 1882 clinical trials and found that only 179 (9.5%) reported the race of patients. Meanwhile, only 100 (5.3%) trials reported ethnicity, and only 95 (5.0%) reported both. Though no studies reported race or ethnicity prior to 1999, there was a roughly 10% increase in trials reporting race (1.7% vs 13.9%) and ethnicity (1.7% vs 11.1%) from 2000 to 2018. Domestic trials were more likely to report race (11.5%) and ethnicity (7.6%) vs international trials (6.9% and 2.3%, respectively).

“The first step in addressing cancer care disparities involves transparency in reporting enrollment of racial and ethnic minorities in clinical trials among women with gynecologic cancers,” the investigators wrote. “Reporting of race and ethnicity should be required for all clinical trials. This data could be used to promote a standard table on race and ethnicity that could be included in all future trials.”

Across the trials which reported these variables, the racial distribution was 66.9% White, 8.6% Asian, 8.5% Black or African American, 0.4% Indian/Alaskan Native, 0.1% Native Hawaiian or Pacific Islander, 1.0% more than one race, and 14.5% unknown. White patients made up more than 80% of the enrolled population in trials for ovarian, uterine, vulvar, and vaginal cancer, and 65.2% of the population in trials for cervical cancer.

Industry-funded trials enrolled higher proportions of White (68.4%) patients vs non­–industry-funded trials (57.5%). Cervical cancer trials reported populations comprising 9.0% Black or African American patients and 18.1% Hispanic patients; those in uterine cancer reported 7.1% and 5.8%, respectively. The vast majority of patients enrolled in vulvar (97.6%) and vaginal (97.5%) cancer trials were exclusively non-Hispanic/Latino/a. Asian patients meanwhile comprised 14.0% of the populations in those trials.

A substantial minority of trials (14.0%) enrolled only White participants, and more than one-third (34.1%) enrolled populations which were at least 90% White. Across cancer types, Black patients were represented at all in 66.5% of trials, American Indian or Alaskan Native patients were represented in 17.9%, and Native Hawaiian or Pacific Islander patients were represented in 7.3%.

“In order to improve disparities among women with gynecologic cancers, we must require reporting of race and ethnicity for all clinical trials, identify barriers to enrolling underrepresented minority subjects, and implement strategies to improve clinical trial diversity,” the investigators wrote.

This retrospective analysis of gynecologic oncology clinical trials registered to the publicly accessible ClinicalTrials.gov was performed in January 2020 and included studies from 1988 to 2019.

Using the website search tool, investigators gathered trials open to patients with cervical (n = 585; 31%), endometrial/uterine (n = 457; 24%), ovarian (n = 1774; 62%), vaginal (n = 92; 7%), and vulvar (n = 102; 5%) cancer. Trials examining more than 1 cancer type were included in the analysis for each type.

According to the investigators, the analysis was limited by the incomplete systemic, provider, and patient information available on ClinicalTrials.gov, which may have led to a selection bias. Moreover, these data do not account for variables known to vary across race and ethnicity, like comorbidities and health care access, and the temporal trends observed therein are limited by the several years (2000-2003, 2005, 2017) in which 3 or fewer trials reported any ethnicity data.

“Participant race and ethnicity are notably underreported in gynecologic cancer clinical trials on ClinicalTrials.gov,” they concluded. “While there have been slight improvements in reporting rates over time, improving gynecologic cancer-related disparities should remain a priority.”


Montes de Oca MK, Howell EP, Spinosa D, et al. Diversity and transparency in gynecologic oncology clinical trials. Cancer Causes Control. Published online October 25, 2022. doi:10.1007/s10552-022-01646-y