New Research Links Food Access to Breast Cancer Biology

Social determinants of health are usually discussed in terms of access—whether someone can get to an appointment, afford a copay, or take time off work. A new study presented at the 2026 ASCO Annual Meeting suggests something more direct may also be happening: where a patient lives, and specifically how easily they can reach healthy food, may be linked to the molecular behavior of their cancer itself.

"We know that social determinants of health and food access impact cancer; they impact cancer outcomes and cancer risk," said Emily Podany, MD, MPHS, of Washington University School of Medicine, who led the study, in an interview with Targeted Oncology. "We asked ourselves: is food access actually influencing metastatic breast cancer biology?”

What the Study Found

Podany and colleagues drew on circulating tumor DNA (ctDNA) data from roughly 850 patients with metastatic breast cancer treated across 4 academic medical centers. "We…looked at whether the ctDNA findings were different based on [if the patient] lived in a low-access food area, or a low-access, low-income area, where there's also poverty," Podany explained. Researchers used the USDA's Food Access Research Atlas to classify patients by census tract, defining low food access for urban patients as more than a mile from a major supermarket and for rural patients as more than 10 miles away.

The biological differences that emerged were specific. "It turns out the low-access patients…have a higher rate of RTK/RAS pathway mutations," Podany says. "It actually seems to be influencing their biology—what they're eating, and whether they're able to eat regularly."

A second, distinct pattern showed up among patients facing both food access barriers and concentrated neighborhood poverty. "In the low-income, low-access patients—patients who not only have low access to food but also, in that census tract, more than 20% of [residents are] living in poverty—those patients actually have a higher rate of CCNE1 mutations, which tends to co-occur with triple-negative breast cancer," Podany said.

The study also surfaced a stark racial disparity layered on top of these biological findings. "The overall survival was shorter for Black patients living in these low-access areas, and overall, low-access areas had patients dying sooner from their metastatic breast cancer," Podany expalined. Outcomes data from the study show median overall survival of 24 months for patients in low-access areas compared with 31 months for those with high food access—and among Black patients with hormone receptor–positive, HER2-negative disease living in low-access areas specifically, median survival fell to just 11 months compared with 38 months for Black patients in high-access areas.

What This Means for Practicing Oncologists

"I think the main takeaway is that this is an initial step," Podany said. "It shows me that food really is a vital sign."

Her recommendation to colleagues starts with something simple: ask the question. "We care about what [a patient’s] blood pressure is, and we care about their comorbidities, but also we do need to ask: Is there food access? Are you food secure?" Podany said. "We know that a lot of patients, unfortunately, are food insecure within the month—they can't feed their families—and so it's really tough for them to take their medications. I think everyone should be asking their patients: Do you have access to healthy food? Do you need a social work referral? Do you need us to help you find food pantries? Those sorts of things can really help with outcomes."

Beyond that immediate screening step, Podany sees the data pointing toward a longer-term research question about treatment personalization. "I do think this is the first step in figuring out if these patients need more genomic testing. Do they need different treatments? How can we personalize the medicine based on what people are experiencing in their day-to-day life?

The way physicians raise the topic, she said, can shape whether patients feel safe being honest. "I think when talking to patients, it's really important that the message be about them, and about personalizing their care and making sure they get the best possible care—so it's less about [them] feeling like a patient."

"Sometimes it's hard to tell people that you can't afford to feed your family. I've heard from patient advocates this is one of the most difficult things for somebody to admit—to tell a person in front of them that they may not have met before, 'Actually, I don't have access to this healthy food,'" Podany added.

Her approach is to keep the conversation anchored to outcomes, not judgment. "I think physicians creating this really warm environment where the patient feels supported, and making sure the patient understands: it's for you, it's for your treatment, it is making sure you get the best possible outcomes," Podany said. "It's so that we can make sure your breast cancer doesn't grow in a way that we could have prevented, by making sure you have access to these healthy foods and making sure you have support."

REFERENCE

Podany EL et al. Impact of food access and poverty on somatic genomic profiles and clinical outcomes in metastatic breast cancer. J Clin Oncol. 44, 1015-1015(2026). DOI:10.1200/JCO.2026.44.16_suppl.1015