Lower socioeconomic status is associated with worse survival among patients with colorectal cancer (CRC), according to two recent studies published in JAMA Network Open.

These findings build on a growing body of evidence linking poverty with worse CRC outcomes, suggesting that more work is needed to address disparities, ideally at a structural rather than an individual level, Adjoa Anyane-Yeboa, MD, MPH, of Massachusetts General Hospital in Boston, and Elena Byhoff, MD, MSc, of UMass Chan Medical School in Worcester, Massachusetts, wrote in an accompanying editorial.

CRC screening presents a unique challenge to individuals living in poverty, Anyane-Yeboa and Byhoff wrote. For example, taking a day off work can have “dire consequences” for such people, including loss of wages needed to pay rent and buy food or even loss of the job itself in cases of precarious employment.

“Systems-level strategies to facilitate CRC screening for patients living in persistent poverty should place the burden on the health care system rather than the patient to find easier ways for individuals to receive cancer screening,” Anyane-Yeboa and Byhoff wrote.

Persistent Poverty Linked to Worse Colon Cancer Mortality

The first of the two new studies, by Leon Naar, MD, of Stanford Medicine, Stanford, California, and colleagues, evaluated retrospective data from a California cancer registry, including 20,015 patients with colon cancer diagnosed from 2017 to 2020. About one third of these patients lived in areas with persistent poverty, whereas the remainder lived in more affluent areas.

Patients in persistent poverty were more likely to be younger, be Hispanic or non-Hispanic Black, and have more comorbidities. After adjusting for these demographic and clinical variables, persistent poverty was significantly associated with approximately 20% higher disease-specific mortality.

Receipt of guideline-concordant care attenuated both the magnitude and statistical significance of this association, suggesting a partial mediation strategy. In contrast, healthcare practitioner density did not mediate the association between persistent poverty and disease-specific mortality, indicating that higher local clinician supply alone does not explain the observed survival differences.

These findings align with previous reports claiming that addition of screening and detection services alone is insufficient to resolve disparities in clinical outcomes, Naar and colleagues wrote in JAMA Network Open.

They suggested two key reasons for this disconnect. First, healthcare density is only partially correlated with availability of care at the individual level. Second, access to care loses relevance when patients do not understand or believe in the value of such care.

“Studies comparing patients with cancer in rural and urban counties have documented differences in health care–seeking behaviors and higher levels of nonadherence to screening recommendations among rural communities,” they said. “Simply increasing the number of available healthcare practitioner in areas of [persistent poverty] may not improve access or clinical outcomes.”

Lower Neighborhood Socioeconomic Status Linked to Worse Metastatic CRC Survival

The second of the two new studies, also published in JAMA Network Open, was authored by Jennifer S. Wang, MPH, of UTHealth Houston School of Public Health in Houston, and colleagues. The authors of this new research pursued a similar line of investigation using a dataset of 3115 young adults (age, 18-49 years) diagnosed with metastatic CRC between 2013 and 2021 at 280 community-based clinics in the US. Specifically, Wang and colleagues evaluated 1-, 2-, and 3-year survival in relation to race/ethnicity and neighborhood-level socioeconomic status.

Their analysis showed that patients living in the lowest socioeconomic quintile had a 51% higher risk for mortality than those living in the highest socioeconomic quintile (hazard ratio, 1.51; 95% CI, 1.24-1.82). Moreover, 1-, 2-, and 3-year survival was significantly lower among Black patients and higher among Asian and Hispanic patients than among White patients. After adjusting for covariates, however, only the association between neighborhood-level socioeconomic status and survival remained statistically significant.

“Neighborhood-level socioeconomic status may act as a proxy for structural racism and/or may independently contribute to survival, as demonstrated in prior studies,” Wang and colleagues concluded, noting that a “multilevel approach” is needed to overcome these disparities.

Strategies to Reduce Survival Disparities in CRC

“At the national level, recent policy changes may make [these disparities] harder to address,” Caroline A. Thompson, PhD, MPH, associate professor of epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, told Medscape Medical News.

“Wang found that patients in lower socioeconomic quintiles were more likely to be on Medicaid or uninsured — exactly the populations now facing new barriers to coverage,” Thompson said in a written comment.

“Medicaid work requirements and eligibility redeterminations are removing people from coverage, and the elimination of ACA marketplace subsidies will make insurance unaffordable for many,” she added. “This is particularly worrying for early-onset CRC, which is rising fastest among adults in their thirties and forties — too young for Medicare but increasingly affected by this disease. You can’t complete a chemotherapy regimen if you can’t maintain insurance coverage.”

Thompson co-authored a 2024 study published in JAMA Network Open that reported 50% higher mortality among younger patients with CRC in impoverished rural areas.

Health systems need to increase efforts to identify disadvantaged patients and then connect them with necessary social services, she said.

“We should recognize that a patient’s zip code is prognostic information. Patients from persistently impoverished areas may need more support to complete treatment, not because of anything they’re doing wrong but because of the barriers they face,” the investigator continued.

On the research side, Thompson called for deeper mechanistic insights, including the relative impacts of the many variables involved, from insurance to caregiving demands.

The findings of the new study that showed a link between persistent poverty and higher disease-specific mortality provide more evidence of a longstanding problem, according to experts.

“Intractable poverty is bad for health,” Anyane-Yeboa and Byhoff wrote in their invited commentary. “In the 36 years since the American Cancer Society released their report on cancer care and outcomes among low-income individuals, little has changed.”

Aaron J. Dawes, MD, PhD, disclosed having relationships with Intuitive Surgical, Inc., and Behind the Knife LLC. Caitlin C. Murphy, PhD, MPH, disclosed having relationships with Universal Diagnostics and Freenome. Anyane-Yeboa disclosed having relationships with Exact Sciences and Takeda Pharmaceutical.