Forecast on Eliminating Cancer Disparities Looks to Ethnic Enclave Research

Scarlett Lin Gomez, MPH, PhD, highlights facts from her research that are impacting cancer disparities and how she is finding ways to improve them.

The American Association for Cancer Research published their 2025 forecast on cancer research and treatment advances. One of the topics highlighted was cancer disparities and prevention, and it was backed by research from Scarlett Lin Gomez, MPH, PhD.

CancerNetwork® spoke with Gomez, a professor in the Department of Epidemiology and Biostatistics at the University of California San Francisco (UCSF), and co-leader of the Cancer Control Program at UCSF Helen Diller Family Comprehensive Cancer Center, focused on specific components such as upstream effects, ethnic enclaves, and climate change.

As an epidemiologist, Gomez uses her background to contextualize research and how it will impact cancer disparities. Her goal in 2025 is to better identify these factors and look for potential solutions to help the affected populations.

CancerNetwork: What are some of the upstream factors that are contributing to disparities in cancer care?

Gomez: When we talk about upstream factors, where it comes to cancer health disparities, we’re talking about what we think of and what the field considers to be these fundamental causes. These are factors that have been defined as social determinants of health, which also are increasingly called the social drivers of health. That’s considered as where we live, the neighborhood aspects of where we live, whether we’re exposed to supportive neighborhood environments in terms of walkability, access to fresh fruits and vegetables, access to high quality health care, as well as environmental factors like air pollution and proximity to toxic exposures, we can also keep moving even more upstream from there and consider what we call the structural drivers, or structural determinants of health.

This is where it gets a little bit more conceptual. The structural drivers are the mutually reinforcing systems that determine the social drivers. These would be our schools, our governments, and the policies that they propose and implement. Our health care systems would be a part of that as well, like zoning laws. All those together, these very big, fundamental structures that determine the immediate environments and resources that particular groups have available to them. We think of these structural drivers, if they’re equitably distributed, if every citizen has equal access to the policies and laws that are in place and the health care institutions are equally made available to everybody, regardless of who they are.Then that would, in theory, reduce the cancer health disparities that we see across the cancer continuum. The reality is that both historically and persistently, that’s not the case.

These large structures are, in fact, inequitably accessible to people. Not only are they inequitably accessible, but they are also, on the basis of marginalized identities like racism, sexism, heterosexism, disability, all of these factors, immigration status and the combination of these, we know that our laws unfairly advantage some groups defined on the basis of these characteristics, and unfairly disadvantage other groups. That’s been the case historically, and that continues to be the case going forward. These are what we think of as the upstream structural and social drivers. If we want to make a dent and want to address disparities downstream, we need to be sure that we address these upstream factors. We can intervene, design interventions to help people to improve their physical activity levels, or improve on an individual level basis and provide access to clinical trials, for example. Unless we keep moving upstream and address those upstream factors, these individual-level interventions won’t have maximal effect, and they’re not going to be sustainable.

Why will focusing on these factors help eliminate disparities?

This is what we call multi-level factors and multi-level research. It’s important to focus on all the levels. From the individual level- and that includes at the biological systems level, at the tumor level- all the way up to the upstream level, these are important to intervene upon. To intervene and identify where the leverage points are, we need data to know where those leverage points are. The thinking for the socio-ecological... model tells us that, yes, all these levels are important. The more upstream we go, those become even more and more fundamental, which makes sense. Because they drive everything downstream. As a scientific community, it has come a long way in the past 10 or so years and recognized the importance of and how critical these upstream factors are. There’s been more funding to study these factors. Research that has started to come out, addressing and identifying the relevance and the importance of these upstream factors, and so I think we’ve made a lot of progress in that regard.

What are ethnic enclaves, and how do they play a role in cancer disparities?

The idea of ethnic enclaves is something that our group has been focusing on quite a bit over the past 10 or so years. Ethnic enclaves are defined as neighborhoods or communities where we see higher concentrations of racial and ethnic groups. We’re focusing on racial and ethnic immigrant groups. The idea, from a sociological and anthropological perspective, is that immigrants come to this country and form enclaves. They form communities, natural or organic communities, whether it’s as neighborhoods or as a social grouping to collectively advocate and provide resources for each other within that community.

Our group has been conducting analytic work to develop measures for characterizing ethnic enclaves. One thing that we’ve learned as we try to advance our knowledge on this is that the nature of ethnic enclaves, specifically Asian and Hispanic enclaves, has shifted over time. It’s important to consider the dynamic change over time within ethnic enclaves, whether it’s been an ethnic enclave that was established in the past and has persisted to become an ethnic enclave, or whether it’s a new ethnic enclave. We have been seeing in our data that those are very different types of ethnic enclaves in terms of who lives there and the resources that are available within them. We think that it's understanding and doing further research to understand how living in ethnic enclaves can result in better or worse cancer outcomes for the residents of those enclaves and can teach us a lot about what specific resources and attributes of those enclaves may be promoting health-wise or maybe deleterious from a cancer outcome standpoint.

We are seeing so far that it’s not always a one-size-fits-all [approach]. In some Asian ethnic enclaves, we see that living in ethnic enclaves, particularly those with a more robust and higher number of ethnic-serving socio-cultural institutions, as we call them, are helpful, so they result in better cancer outcomes for the Asian American residents of those enclaves. We suspect the pathways to that would be through things like providing language resources, healthy foods that are affordable, and housing. In many of these enclaves, cancer screening services are mobile vans that are brought to those communities specifically. For other enclaves, our research that compared Hispanic patients living in enclaves in Texas didn’t necessarily show the same thing where it came to breast cancer outcomes. These are good lessons learned for us as we dig in deeper and understand what the mechanisms are and specific resources or lack thereof within these ethnic enclaves that we can leverage to improve cancer outcomes for everybody.

Your previous answer touched upon this, but can you expand upon research that has pointed to any specific population that may have better outcomes?

Our focus has been a lot on disparities and conducting research for groups that are experiencing disparities. What are the factors that are driving the disparities? [This research] needs to continue and ramp up. There is also value in looking at population groups that experience more favorable outcomes because we could potentially learn about why that is and apply that knowledge to all groups. One group and one outcome that we have been interested in, and we have a study looking at, is that we’ve long observed that breast cancer survival or mortality rates after a diagnosis of breast cancer seem to be better among almost all groups of Asian Americans compared with other racial and ethnic groups. We have a multi-site study that we’ve been conducting to try to understand what those factors are. Are they behavioral factors? Is it a treatment? In this study we’re hoping to get at specific, detailed treatment modalities. Is it something about the types of tumors that are diagnosed among Asian women compared with other racial and ethnic groups? Is it more socio-cultural factors like quality of life? These are the types of multi-level factors that we’re investigating in this study. We hope that we can come away with an understanding of why we’ve been observing this for a long time. Why do Asian American women have better survival following breast cancer than other racial and ethnic groups? Hopefully that knowledge can apply more generally to other groups that are experiencing disparities.

Why have you identified climate change as impacting disparities?

This has been an interesting topic and one that’s admittedly new to me, but from the talks that I’ve heard and the literature that I’ve read, I’ve come to appreciate that it’s an area we need to pay attention to when it comes to cancer disparities. [This is] not only because it’s an increasing concern [that] we’re going to be seeing more weather-related natural disasters and that impacts our daily lives, but also from a disparity standpoint, we have already started to see and conceptually can understand that it would have a more dire impact on vulnerable populations compared with others.

This is still at such an early stage because we haven’t had a lot of research in this area, specific to cancer. One of the priorities should be that we should be conducting more studies of climate change, all the different aspects and sequelae of climate change, and its impacts across the cancer continuum. There’s been a few commentaries written about this. All these commentaries and reviews talk about how different aspects of climate change and weather-related changes can impact different aspects of the cancer continuum. It’s been documented that they can impact the access to treatments. There’s been a few studies that have shown, following extreme weather events like hurricanes, how population groups had difficulty accessing adjuvant chemotherapy or radiation, for example. You can certainly imagine that groups that already have difficulty are going to have more difficulty.

Another example is areas where we’re seeing an increase in or decrease of more extreme temperatures. You would expect that populations within those neighborhoods may be less likely to have the resources to be able to cope with those temperature-related changes. Another example is very real to those of us who live in California--the recent fires in Los Angeles—because, and this is an example of an upstream factor having an impact on the downstream potential health consequence, we know that certain neighborhoods were affected by the fire [more].

What steps can begin to be taken to eliminate disparities and allow for more equal opportunity of care?

We have enough knowledge in hand to be able to design interventions and conduct implementation science studies to try to get to that point of more equal opportunities to care. Some of these big structural issues, like insurance access, feel big and daunting to the extent that we can keep documenting that they are important and how they are specifically important. Studies can document the economic impact of addressing these upstream factors, and how they ultimately result in lower costs overall in care. If we can ensure equal access for all segments of the population, that will be impactful as well. Especially with the last [National Cancer Institute] director that we had, there were a lot of initiatives and programs put towards improving community access to clinical trials, and those are helpful models for improving access to cancer cares working through established community centers. This is where a lot of the residents, especially underserved populations, go for their care, not only because that’s who they can access, but also because it’s who they trust, oftentimes. These community health centers also are the ones who are more culturally and linguistically in tune with the needs of their communities, so engaging these community health centers to a much, much greater extent as we go forth to through the cancer continuum from prevention to treatment to survivorship, will be critical, and can go a long way towards providing more equal opportunity to cancer care.

Reference

Experts Forecast Cancer Research and Treatment Advances in 2025. AACR. January 10, 2025. Accessed February 10, 2025. https://tinyurl.com/mtmutntm