The presence of precision medicine navigators may increase the likelihood that patients with prostate cancer, especially Black patients, will receive genomic testing that may help predict the severity of their disease and guide treatment, according to findings presented by Allen et al at the 2023 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 122).
Background
Black patients are 76% more likely to be diagnosed with prostate cancer and 120% more likely to die from the disease than White patients. This disparity may stem from many factors—including lower rates of early prostate cancer screenings that result in more aggressive cancers by the time Black patients receive their diagnoses.
“Black patients with prostate cancer in the [United States] have disparately worse clinical outcomes compared [with] other racial groups,” stressed lead study author Alexander J. Allen, MD, a radiation oncology resident physician at the University of Maryland Medical Center.
Genomic testing is used to gauge the likelihood that cancer will metastasize within the next 5 to 10 years. Previous studies have suggested that genomic testing may be better at predicting the risk of metastases than conventional prostate cancer tests such as the Gleason score and prostate-specific antigen levels. Oncologists often use the results of all three tests to guide treatment decisions.
“Genomic testing provides additional information that can alter a patient’s treatment plan,” explained Dr. Allen. “For example, if Gleason scores and [prostate-specific antigen] levels suggest a patient has an intermediate risk for metastases, but the genetic analysis categorizes them at high risk because of the biological makeup of the tumor, then you might intensify treatment,” he emphasized.
Precision medicine navigators act as liaisons between patients and the health-care system. Their role is centered around identifying patients who may be eligible for genomic testing and ensuring that they receive this testing.
“Obtaining genetic tests in a clinical setting is complex and requires knowledge of the submission requirements,” Dr. Allen noted.
After working with health-care providers to identify which patients are eligible, the precision medicine navigator helps the patients fill out requisition forms and coordinates the submission of biopsy tissue samples to the appropriate genomic testing company.
“Our findings suggest hiring a precision medicine navigator who specializes in genetic testing can improve the rates of Black patients receiving these tests, which could potentially reduce health disparities and improve outcomes,” Dr. Allen added.
Study Methods and Results
In the new study, researchers compared how frequently patients with prostate cancer received genetic testing from the 7 months prior to the arrival of a precision medicine navigator to the 7 months following the creation of the position. Among the 693 patients involved in the study, 44.9% (n = 311) of them were treated prior to the arrival of the precision medicine navigator and 55.1% (n = 382) of them were treated after the navigator had arrived. The median age in both groups was 68 years, and 60.1% and 60.2% of the patients identified as White, 35.1% and 34% identified as Black, 3.2% and 3.7% identified as Asian/Pacific Islander, and 1.3% and 2.1% identified as Latino. There were no statistically significant differences between the two groups in disease severity, type of insurance coverage, or type of facility in which treatment was administered.
The researchers found that the patients who were seen by the precision medicine navigator were substantially more likely to receive genomic testing than those who were not seen by the navigator. For instance, Black patients seen by the precision medicine navigator were sixfold more likely to receive genomic testing than those who were not seen by the navigator. Following the arrival of the precision medicine navigator, the proportion of Black patients referred for genomic testing rose from 19% to 58%. Similarly, genomic testing rates also increased from 20% to 64% for lower-income patients, from 20% to 68.5% for those on Medicare and Medicaid, and from 6% to 77% for patients receiving treatment at community hospitals.
Conclusions
“We thought there would be some increase but did not expect the testing rates to grow so substantially. The most common way treatments were altered based on genomic testing results was in whether or not patients with intermediate-risk disease were given hormone blocking therapy,” Dr. Allen noted.
In further studies, the researchers plan to investigate whether the increased rates of genomic testing ultimately lead to better patient outcomes.
However, ensuring that genomic testing is available to all patients who might benefit may be key to reducing racial disparities in prostate cancer. Precision medicine navigators are not funded through traditional business models, suggesting that novel funding mechanisms may need to be initiated to decrease disparities.
“We theorize that if patients are treated differently based on this new genome-based risk stratification, outcomes will improve. As precision medicine becomes more mainstream, it has the potential to alleviate disparities. But if there are no measures taken to ensure access to these tools, we could just be maintaining or even worsening the health inequities that we have today,” Dr. Allen concluded.
Disclosure: For full disclosures of the study authors, visit redjournal.org.
