Redlining Linked to Breast Cancer Survival Gaps: Sarah M. Lima, PhD, MPH

Historical redlining was associated with worse survival outcomes for patients who lived in D-grade, hazardous neighborhoods, according to a recent study published in Cancer.¹

In this interview with the study’s lead author, Sarah M. Lima, PhD, MPH, an epidemiologist and postdoctoral fellow in cancer populations at the Georgetown Lombardi Comprehensive Cancer Center, she dives into the study’s findings and what they mean for patients with breast cancer today.

This interview has been lightly edited for clarity.

AJMC: Your study shows survival disparities narrowed for a period of time but then widened again in 2015-2019. What do you think may be driving that recent reversal?

Lima: The way to think about this is that a lot of public health research, or at least the viewpoint that I ascribe to, has this fundamental view of root causes of disease and why we see differences by groups. And this fundamental cause theory suggests that disease, and especially disparities in disease, ultimately come from differences in socioeconomic resources or the the ability to access those resources, which makes a lot of intuitive sense.

When we see redlining as a comprehensive measure for how beneficial their socioeconomic resources are and how their environment is, then we can see those differences over time. We saw that in the disparities by redlining grades, there were differences in mortality when comparing women who lived in the A-graded, best neighborhoods to those in the D-graded, hazardous neighborhoods, and that over time, that attenuated. And some of the ways we think that happened is because in the 1990s, that was a big time for breast cancer advances in treatment and screening.

We see mammography become really popular in the mid-1980s, and we see the development of new cancer therapies in the 1990s. And what we think happened—and this is consistent with that fundamental cause theory—is that the women who live in those A-graded neighborhoods are then in that higher access class, and they're going to be able to access those treatments because they have health insurance or they have money to pay for it. They're going to be going to the hospitals that are aware of these new developments or even have clinical trials going on, and as time goes on, from those advances, those new treatments and screening options will become more common and widely dispersed, such that then you see women who live in these D-grade neighborhoods are probably starting to access them more.

That's a way in which we could see those disparities narrow over time, especially since the 1990s, and in terms of the more recent widening, we think that that could be because we're seeing even more new treatments being developed in breast cancer. CDK64/6 inhibitors are a new one, as well as PARP inhibitors, and those are therapies that were developed and approved within the 2015 to 2019 period. We would expect to see, with that new medical innovation, that women in that higher socioeconomic class here, being in that A-grade neighborhood, might be able to access that sooner and at a higher rate than the women in D-grade neighborhoods.

AJMC: In the late 1990s, residents of D-graded neighborhoods had a 75% higher risk of death compared with residents of A-graded areas. What does that statistic reveal about the long-term health impact of structural housing policies?

Lima: I think it is, ultimately, just another piece of evidence that these structural housing policies are really proxying socioeconomic, environmental, and healthcare access conditions today, even though they're outlawed. With this one specifically, we think that it's signaling that the women in those A-graded neighborhoods are, across the board, able to access new treatments at a higher rate. Whether that's because they're more insured, because the hospitals they go to know about it more, or even on an interpersonal level. Physicians are generally high-income, well-educated, and probably live in those A-graded neighborhoods. Women in A-graded neighborhoods might even personally know a physician and be able to get into care a little bit sooner. These are all different ways that this sort of comprehensive grading system can combine these forces together and lead to this difference.

AJMC: Your study found that redlining-related disparities were most pronounced in patients with less advanced tumors. Why might neighborhood conditions influence survival even when cancers are diagnosed earlier?

Lima: We've seen this in other work, where we see survival disparities are biggest for the types of cancers or stages of cancer that are most amenable to treatment and screening. And we see that because that's when you can have those differences based on resources or based on social class, it can come up.

With distant-stage cancers, whether you're a woman who is very high income or lives in this A-grade neighborhood, or whether it's a woman who is lower income, distant-stage breast cancer is a more fatal cancer. The odds of being able to survive it are worse for everyone. But there's still going to be a benefit to higher-income women, but the relative benefit compared to lower-income women might be a little bit less, just because the actual disease itself is more fatal when you go to the early stage.

In local-stage disease, you can see those differences play out just because that is a place where we can see large improvements in survival based on treatment. If a woman can access those treatments or can access screening at a higher rate, then you can't see those differences, so that's ultimately how you can see these disparities by redlining and grade playing out with the more treatable diseases.

AJMC: The worsening disparities over time in hormone receptor–positive tumors stood out as particularly striking. What might explain why outcomes are diverging in this subtype?

Lima: This is a new area, and I'm a cancer epidemiologist; I don't focus on pharmacology, but this is where our pharmacist friends would really be able to give a lot of input. But the more treatable forms of disease are ones that we would expect to see large differences in based on these socioeconomic variables, including redlining with the ER-positive or hormone receptor-positive cancers. Generally, those are ones for which there are multiple treatment options. We would expect those disparities to be larger compared to hormone receptor-negative or triple-negative breast cancer. And looking at how those specific cancers have been, we've been seeing the disparity widen over time, rather than narrow.

We assume that’s because there's been more hormone-based tailored treatments being developed, so drugs that target those hormone receptors or are made and developed based on hormone receptor status. Again, just going back to that idea, we can see these disparities exist in part because the access to treatment and to care through a lot of different modalities is fundamentally different by socioeconomic status or redlining status.

AJMC: What role do you think access to screening, treatment quality, and follow-up care play in the survival differences you observed across historically redlined communities?

Lima: We think that it, of course, plays a large role, especially with the treatment side, in terms of the screening. We tend to see that screening is pretty high in these communities and not as different. One of the other studies we did was looking at breast cancer risk and survival factors by redlining, and we surprisingly didn't see that mammography was a major difference. We don't have a lot of evidence that we would be able to improve these outcomes by expanding screening, or at least not to a large degree.

I think the big difference that we'll see is that as these drugs develop, we'll see differences by hospital in terms of uptake of them. If it's a research-based hospital, they'll know about it; they'll start integrating it into some of their care, whereas maybe a federally qualified health center doesn't have either the capacity to do so or they just learn about these things a little bit later compared with those research-based hospitals, as well as the insurance and access to that care.

Thinking about these things in a structural way, redlining is ultimately a structural problem, and this is something that's going to require a structural solution. Thinking about ways to expand health insurance access as well as the type of drugs that are covered by insurance, such as Medicare, and expanding that, as well as trying to make the delivery of these new medical innovations on the hospital-level system, then we may start to see some of these disparities reduced.

AJMC: How do these historically disinvested neighborhoods continue to disproportionately affect outcomes for women of color, and what does this reveal about structural inequities in cancer care?

Lima: There are a couple of ways to look at this. First, we see that a worse redlining grade significantly increases a woman's mortality risk across race and ethnicity groups except for Hispanic women. We found that living in a D-grade neighborhood increases the mortality risk 25% for non-Hispanic Black women, 65% for non-Hispanic Asian/Pacific Island women, and 45% for non-Hispanic White women compared to their counterparts living in an A-grade neighborhood. And we find the same general pattern across time for these groups, too. Overall, this really tells us that there is something about these neighborhoods, whether socioeconomic or environmental, and how redlining policy shaped them that continues to bring mortality risks over a long period of time.

Living in a historically redlined neighborhood is bad for survival, no matter what race or ethnicity the patient is, but the second important thing to recognize is that the likelihood of living in a historically redlined neighborhood is much higher for women of color. Across the 1995-2019 period, we found that non-Hispanic White women made up 76% to 89% of cases living in an A-grade neighborhood, depending on the time period. This is really consistent with the original intention of the historical redlining grades when they were made in the 1930s, which was to keep A-grade neighborhoods (and home-owning neighborhoods) mostly White, high income, high education.

In my opinion, I think the solutions are going to ultimately need to be on the policy level and target mitigating poverty and exposure to environmental pollutants. I want to clarify I don't have expertise in health services, but I think in lieu of such policy changes, it's important for physicians and healthcare providers to understand the impact of where patients live on their outcomes. Whether that's health centers targeting redlined areas for telehealth, mobile clinics, or physicians offering low-income-friendly recommendations, such as minor physical activity/walking to improve breast cancer survival.

Given that we believe this study's results reflect differential access to medical innovations, this could also mean healthcare providers advocate for low-income and under-insured or uninsured patients to get better access to newly developed treatments. Finally, I think physicians and health workers are a very powerful voice in terms of advocacy and could help to push for those upstream policies that would, in my opinion, do the most to improve breast survival and reduce these disparities.

AJMC: What do you see as the most important takeaways from this study, and what message do you hope clinicians, researchers, and policymakers walk away with after reading these findings?

Lima: I think the ultimate thing that I would just hone in on is that we keep finding that the neighborhood is an important setting for disease, including cancer, and that this is something that we really need to reconcile with and that stakeholders and policymakers need to start addressing these neighborhood-level determinants, and that we'll see some downstream or later-on improvements because of that.

The other thing is that redlining, ultimately, was created in order to maintain property values, and while redlining is outlawed itself, we do continue to have a mortgage and housing system that is ultimately based on that principle, ensuring that our properties have the highest value. And we could redesign the way we think about housing and real estate markets, such that we develop neighborhoods according to what would prioritize health or quality of life as opposed to property value. And we would expect to see some pretty big improvements in population health if we did start making these places to prioritize the health of the residents rather than just how much the land costs.

References

1. Lima SM, Palermo TM, Tian L, et al. The effect of time on associations between historical redlining and breast cancer survival. Cancer. Published online February 9, 2026. doi:10.1002/cncr.70230