Common Ovarian Cancer Blood Test May Miss Diagnoses in Black and Native American Women
A frequently used blood test for ovarian cancer may not accurately detect the disease in some Black and Native American patients, potentially delaying necessary treatment, according to a recent study. This finding underscores the ongoing issue of medical tests contributing to inequities in healthcare.
Racial Disparities in Ovarian Cancer Detection
Researchers are actively investigating biases within medical practices. The latest research highlights a critical disparity: Native American women experience the highest rates of ovarian cancer, while Black women diagnosed with the disease face lower survival rates compared to white women. Early detection of ovarian cancer is crucial for improving patient outcomes and increasing survival chances.
Study Focuses on CA-125 Test Accuracy
The new research, supported by the National Cancer Institute and published in JAMA Network Open, examined the effectiveness of the CA-125 blood test. This test measures a tumor marker in the blood and is used by physicians to determine if a patient with a suspicious mass requires referral to a cancer specialist.
Dr. Shannon Westin of MD Anderson Cancer Center in Houston, who was not involved in the study, emphasized the importance of understanding test result implications across diverse racial and ethnic groups, particularly during initial assessments. “This is a perfect example of work that absolutely needed to be stratified based on race and ethnicity,” Dr. Westin stated, highlighting that the findings should caution doctors against relying solely on normal test results.
Potential Reasons for Test Inaccuracy
The reasons behind the test’s varied performance across different populations are currently unclear. Researchers hypothesize a connection to a benign genetic variation more prevalent in individuals of African, Caribbean, Middle Eastern, and West Indian descent.
It’s important to note that initial studies of the CA-125 test, conducted primarily in the 1980s, did not consistently record participants’ race and predominantly included white populations.
Consequences of Delayed Diagnosis
Dr. Anna Jo Smith of the University of Pennsylvania’s medical school, the lead author of the study, acknowledged that the CA-125 test is not infallible even for white women. However, she stressed the exacerbated risks for minority groups: “But if we have worse performance in certain groups, then we may be further contributing to disparities in referral, disparities in treatment, and ultimately we may be contributing to the lower survival in Black women with ovarian cancer.”
Key Findings on Elevated Levels and Treatment Delays
Analyzing data from over 200,000 women diagnosed with ovarian cancer between 2004 and 2020 who underwent CA-125 testing, researchers made significant findings:
- Black and Native American patients were 23% less likely to exhibit elevated CA-125 levels at the time of ovarian cancer diagnosis compared to white patients. This suggests that current benchmarks for elevated levels may be set too high for these populations.
- Patients with false negative results experienced a delay in chemotherapy initiation, starting treatment an average of nine days later than those with elevated CA-125 levels. This delay could negatively impact patient outcomes, according to Dr. Smith.
Proposed Solutions and Future Guidelines
Dr. Smith and her team presented their findings at a recent Society of Gynecologic Oncology meeting, proposing a revised, lower threshold for the CA-125 blood test to improve accuracy across all populations. This research has the potential to influence future clinical guidelines.
“New thresholds for referral will ensure that all patients get in for prompt care when ovarian cancer is suspected,” Dr. Smith concluded, emphasizing the importance of equitable access to timely diagnosis and treatment.