A screening tool used to evaluate the need for endometrial cancer biopsies in women frequently misses the signs of this cancer in Black women, according to a new study published by Kemi M. Doll, MD, and colleagues in JAMA Oncology.
Dr. Doll, a gynecologic oncologist at the University of Washington School of Medicine, said that the results of the study suggest that the current noninvasive option of transvaginal ultrasound to determine the appropriateness of a biopsy is not sufficiently accurate or racially equitable with regard to Black women.
Kemi M. Doll, MD
"Black women have an over 90% higher mortality rate after diagnosis of endometrial cancer compared with White women in the United States," stated Dr. Doll. "This is a long-standing disparity that we have yet to make meaningful progress to address. Although we have focused before on evaluating access to health care, in this study we sought to evaluate the guidelines themselves."
Issues With Screening
The research used a simulated retrospective cohort study, based on data from the Surveillance, Epidemiology, and End Results (SEER) national cancer registry collected from 2012 to 2016 and U.S. Census data. Another cohort was constructed (again using SEER data), from February 2, 2020, to August 31, 2020, while analysis of the data occurred from September of last year through March 2021.
In all, a total of 367,073 simulated Black and White women with postmenopausal bleeding were evaluated, including 36,708 with endometrial cancer, for this study. Based on these simulated cohorts, transvaginal ultrasound endometrial thickness screening missed over four times more cases of endometrial cancer among Black women vs White women, owing to the greater prevalence of fibroids and non-endometrioid histology type that occurs among Black women.
"This puts Black women at a higher risk of false-negative results," Dr. Doll said. "That is unacceptable in a group that is already the most vulnerable to the worst outcomes of endometrial cancer."
One clinical pathway for determining whether a biopsy is needed is to do a transvaginal ultrasound to measure the thickness of the endometrium or uterine lining, Dr. Doll noted. Usually, a biopsy is then scheduled if the lining is 4 mm or greater, she said. "But not all endometrial cancers increase the lining thickness," Dr. Doll said. "In addition, noncancerous fibroids can make the lining harder to measure."
The transvaginal ultrasound strategy using a test of endometrial thickness for further biopsies and testing was developed on large population-based studies from Scandinavia, Italy, and Hong Kong. Black women were not included in these studies.
The magnitude of the racial inequity in endometrial cancer survival is larger than that seen in cervical, breast, or colon cancers, and is increasing, the report notes. Two independent factors in excess death among Black women are the higher likelihood of advanced-stage disease at diagnosis, and the greater prevalence of high-risk endometrial cancer among Black women compared with White women.
The next step is to do a real-world study to confirm these results, Dr. Doll said. However, clinicians should realize the potential for missed diagnoses by using only transvaginal ultrasound. Black women with fibroids should discuss a biopsy, instead of relying only on the less-invasive transvaginal ultrasound screening, she added.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
