Advancing Precision Medicine in Oncology

Efforts to expand precision medicine across diverse cancer patient populations are gaining momentum, driven by new research highlighting persistent gaps in access and outcomes for underrepresented groups. While advances in genomic testing and targeted therapies have transformed cancer care for many, significant disparities remain based on race, ethnicity, socioeconomic status, and geographic location, limiting the equitable application of these innovations.

A recent analysis published in JAMA Oncology examined clinical trial participation and molecular profiling rates among cancer patients in the United States, revealing that Black, Hispanic, and Indigenous patients are consistently less likely to receive comprehensive biomarker testing compared to their white counterparts. This testing is essential for identifying actionable genetic mutations that guide the use of FDA-approved targeted therapies and immunotherapies.

The study, which analyzed data from over 1.2 million cancer patients diagnosed between 2013 and 2022, found that only 38% of Black patients and 41% of Hispanic patients with non-small cell lung cancer underwent recommended PD-L1 or EGFR testing, compared to 52% of white patients. Similar disparities were observed in colorectal, breast, and prostate cancers, where testing rates for KRAS, HER2, and homologous recombination deficiency (HRD) biomarkers lagged significantly in minority populations.

Experts attribute these gaps to a combination of systemic barriers, including limited access to major cancer centers equipped for advanced diagnostics, implicit bias in clinical decision-making, inadequate patient navigation support, and insufficient representation in genomic databases that inform test interpretation. Many existing reference panels used to classify genetic variants are primarily based on data from individuals of European ancestry, increasing the risk of ambiguous or misinterpreted results in other populations.

“When a patient’s genetic profile doesn’t match the reference databases we rely on, variants of uncertain significance are more likely to be reported,” said Dr. Lisa Newman, Director of the Breast Cancer Screening Program at Weill Cornell Medicine and NewYork-Presbyterian. “This can lead to delayed or denied access to effective treatments, not because the therapy wouldn’t work, but because we lack the data to confidently act.”

In response, several major cancer networks and research consortia have launched initiatives to diversify genomic databases and improve access to testing in community settings. The National Cancer Institute’s (NCI) Molecular Analysis for Therapy Choice (MATCH) trial, now in its second phase, has expanded enrollment criteria to include more patients from rural and underserved areas, with targeted outreach through safety-net hospitals and federally qualified health centers.

Similarly, the American Association for Cancer Research (AACR) Project GENIE registry, which aggregates real-world genomic data from participating cancer centers, has prioritized inclusion of data from historically underrepresented institutions. As of 2024, GENIE includes genomic profiles from over 120,000 patients, with increased representation from Black, Hispanic, and Asian patients through partnerships with centers like MD Anderson Cancer Center’s Oncology Equity Initiative and the Robert H. Lurie Comprehensive Cancer Center’s Disparities Research Program.

Community-based programs are also showing promise. In Alabama, the Deep South Network for Cancer Control has deployed trained community health workers to educate patients about biomarker testing and assist with logistics such as transportation and insurance coordination. Early results from a pilot program showed a 40% increase in testing completion among enrolled Black patients with advanced colorectal cancer.

Despite these efforts, challenges remain. Reimbursement policies vary widely across state Medicaid programs, with some not covering multi-gene panel testing or liquid biopsies for certain cancer types. Workforce shortages in genetic counseling—particularly in rural areas—limit the ability to explain complex test results to patients and families.

“Precision medicine only works if it’s precise for everyone,” said Dr. John Carethers, Chair of the Department of Internal Medicine at the University of Michigan Medical School. “We need to invest not just in the science, but in the infrastructure that ensures all patients can benefit from it—regardless of where they live or who they are.”

Ongoing research is also exploring how social determinants of health influence tumor biology and treatment response. Emerging evidence suggests that chronic stress associated with discrimination and environmental exposures may contribute to molecular differences in tumors, further underscoring the need to consider context when interpreting genomic data.

As cancer care continues to evolve toward increasingly personalized approaches, experts agree that equity must be embedded in the design of precision medicine initiatives from the outset—not added as an afterthought. Without deliberate action to close existing gaps, the benefits of advances in genomics and targeted therapy risk being unevenly distributed, exacerbating existing disparities in cancer outcomes.