Communities of different ancestral (i.e. genetically derived) backgrounds can have distinct genetic variations. These changes can be medically relevant and may inform how a patient responds to a medicine. Genetic variations play an increasingly central role in personalized healthcare, because they can help healthcare professionals to identify which patients will benefit from specific treatments.
But, to determine which treatments will work best for which patients requires a great deal of clinical and genomic data. Currently, data available for public study is composed mostly of European populations. With little representation from communities of non-European descent, it can be difficult to associate diverse genetic variants with disease process.
To achieve health equity among all patient populations, we need to broadly understand genetic variations across individuals of different ancestries and establish potential links between variation and health outcomes across all communities.
We also need to determine why certain communities have better health outcomes. Is it due to biology or preventable health disparities — such as limited access to or insufficient quality of optimal clinical care — or more likely, a combination of factors? Answering these crucial questions will provide a clear path toward improving treatment outcomes for all patients.
We presented two abstracts (discussed below) at the 12th Annual American Association for Cancer Research Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved that address these topics.
Does equal access to biomarker testing result in better patient outcomes?
We studied nearly 4,000 non-small cell lung cancer (NSCLC) patients to better understand why there are well documented racial disparities in cancer outcomes. Specifically, we assessed the contribution of variations in genetic factors by ancestry and access as a key social determinant. The biomarker assessed was tumor mutational burden (TMB), an important predictor of response to cancer immunotherapy.
The study showed that different TMB levels are found across different ancestral groups, and that higher TMB is associated with better survival in patients who received cancer immunotherapy. Because all participants in this study had access to TMB testing and immunotherapy, any observed differences in health outcomes would more likely be attributable to biological factors rather than inequitable access to care, though other broader social determinants were not assessed in this analysis.
Giving equal access to TMB testing and immunotherapy to patients with high TMB resulted in better outcomes than patients with low TMB, regardless of ancestral background. This data shows that, in NSCLC patients who exhibit no disparities in the receipt of treatment, there are similar outcomes observed across ancestries.
These findings underscore the necessity of ensuring that all cancer patient populations have access to cancer immunotherapy and TMB testing.
What can we do to make clinical research more inclusive?
The study previously discussed shows that, given enough and the right data, we can better understand the contributions of biologic drivers and access to care on health outcomes. To improve the cancer care continuum for all, we need to ensure that communities of non-European descent are increasingly represented in clinical studies.
To make progress toward this goal, the Diverse Cancer Communities Working Group studied processes and best practices at select cancer centers of excellence. Based on the group’s findings, a set of recommendations was developed that is aimed at recruiting more patients with diverse ancestries into cancer clinical studies. These include:
- Improving patient navigation to ensure that patients receive the support they need to participate in the cancer care continuum. This is important for all patient populations, especially those that are underserved.
- Excelling in community engagement to build trust among non-Caucasian and underserved populations.
- Implementing changes to the healthcare system that have proved successful at the centers of excellence, such as engaging with providers and community leaders.
Rigorous scientific studies into the underlying biological drivers of disease and increased participation from diverse populations in clinical studies, as well as increased awareness among healthcare professionals, are needed to best treat all patients in this evolving world of personalized healthcare.
To advance better health outcomes for all, clinical research must reflect demographic trends and include more diverse populations. At Genentech, a member of the Roche Group, we aspire to improve health for communities of all racial and ethnic backgrounds.
We cannot do this alone. Collaboration across the industry, from healthcare systems to academia, is critical to ensuring that all communities are reflected so that we may develop the treatments and medicines that all patients need.