Low Socioeconomic Status Raises Mortality Risk in Young Adults With mCRC

In a cohort of young adults with metastatic colorectal cancer (mCRC), 3-year survival was lowest among Black patients and those of the lowest socioeconomic status (SES), but only the latter remained significantly associated with survival after adjustment, according to a study published in JAMA Network Open.¹

Investigating Survival Disparities Among Young Adults With mCRC

Although CRC incidence rates have declined among older adults, they have alarmingly increased in young adults, defined as individuals aged 18 to 49 years. Between 2010 and 2019, mCRC incidence increased by 22% in this population, from 3.3 to 4.0 per 100,000. As a result, CRC is now the leading cause of cancer-related death among young men in the US and the second leading cause among young women.²

The researchers highlighted that CRC disproportionately affects historically minoritized racial and ethnic groups.¹ Neighborhood-level SES has also been associated with higher CRC incidence and poorer survival outcomes. However, much of the prior research on racial, ethnic, and socioeconomic disparities in CRC has relied on population-based cancer registries, which tend to overrepresent urban and foreign-born populations and often lack detailed treatment- and tumor-related data. Other studies have used data from a single center or an academic setting, limiting the generalizability of their findings.

To address these knowledge gaps, the researchers examined survival differences by race, ethnicity, and neighborhood-level SES in a diverse, community-based sample of young adults with mCRC. They used data from the nationwide Flatiron Health database, which includes de-identified information from more than 280 community-based cancer clinics and represents more than 3.5 million patients with cancer. The study population included young adults diagnosed with de novo or recurrent mCRC between January 1, 2013, and December 31, 2021.

Race and ethnicity data were obtained from the Flatiron Health database, whereas neighborhood-level SES was determined using census block group data (2010 Census boundaries) based on the most recent address in the electronic health record. The researchers noted that Flatiron Health used 5-year estimates from the American Community Survey (2015-2019) to calculate the Yost Index, a composite measure of 7 variables that reflect multiple aspects of neighborhood-level SES.

Using Kaplan-Meier methods, they estimated 1-, 2-, and 3-year survival overall and stratified by race, ethnicity, and neighborhood-level SES, with comparisons made using log-rank tests. Patients were followed from mCRC diagnosis until death or December 31, 2022, whichever occurred first. The researchers also used Cox proportional hazards models to analyze associations between race, ethnicity, neighborhood-level SES, and all-cause mortality after adjusting for relevant covariates.

SES Drives Mortality Risk in Young Adults With mCRC

The researchers identified 3115 eligible young adults with mCRC. The mean (SD) age at diagnosis was 42.4 (5.9) years, and most patients were male (n = 1651; 53.0%). Regarding race and ethnicity, White individuals comprised the majority of the cohort (n = 1874; 60.2%), followed by Black (n = 424; 13.6%), Hispanic (n = 395; 12.7%), and Asian (n = 122; 3.9%) patients; meanwhile, 9.6% (n = 300) were categorized as other, which represented American Indian or Alaska Native, Hawaiian or Pacific Islander, and/or multiracial individuals.

At 3 years post-diagnosis, Black patients had worse survival (41%; 95% CI, 36%-46%) than White patients (47%; 95% CI, 45%-49%). In contrast, Asian (58%; 95% CI, 48%-66%) and Hispanic (53%; 95% CI, 48%-58%) patients experienced better 3-year survival than White patients.

Differences were also observed by neighborhood-level SES, with 3-year survival of 41% (95% CI, 36%-45%) among patients in the lowest quintile vs 59% (95% CI, 54%-63%) among those in the highest quintile. After adjusting for covariates, only neighborhood-level SES remained significantly associated with survival (lowest vs highest quintile: HR, 1.51; 95% CI, 1.24-1.82).

Addressing Structural Inequities to Reduce mCRC Survival Disparities

The researchers acknowledged several limitations, including the small sample size for Asian patients, which caused imprecise estimates. Also, Asian, Hispanic, and other race groups were aggregated and may not reflect or be generalizable to disaggregated groups. Nonetheless, they expressed confidence in their findings.

“Our findings demonstrate the role of upstream structural conditions, such as inequitable distribution of resources in low-SES neighborhoods, that impact survival in this growing population and highlight the need for multilevel interventions and policies to reduce disparities,” the authors concluded.

References

1. Wang JS, Johnson B, Murphy CC. Racial, ethnic, and socioeconomic survival disparities in early-onset metastatic colorectal cancer. JAMA Netw Open. 2026;9(1):e2553146. doi:10.1001/jamanetworkopen.2025.53146
2. Siegel RL, Giaquinto AN, Jemal A. Cancer statistics, 2024. CA Cancer J Clin. 2024;74(1):12-49. doi:10.3322/caac.21820