Patients with early-onset colorectal cancer living in rural vs urban areas were found to have a lower likelihood of 5-year survival, with persistent poverty compounding this association in some age groups, according to an analysis published in a research letter by Tsai et al in JAMA Network Open.
“For example, patients aged between 30 and 39 years living in rural and impoverished areas had a 50% greater risk of death from colorectal cancer than those living in other areas,” the investigators commented. “This intersecting association with risk of death from colorectal cancer was also more pronounced for patients with early-onset colorectal cancer by 30% compared with 19% in those with average-onset colorectal cancer.”
Study Details
Using the 2006 to 2015 Incidence Data with Census Tract Attributes from the Surveillance, Epidemiology, and End Results (SEER) program, the investigators identified 58,200 patients with early-onset colorectal cancer, defined as diagnosis before age 50. Of this population, 42,694 were between the ages of 40 and 49 (73%), 30,580 (53%) were male, and 1,346 (21%) lived in rural areas with persistent poverty.
The outcome of interest was cause-specific survival for colorectal cancer; deaths from other causes were censored. Exposures of interest included census tract persistent poverty (yes vs no) and rurality (yes vs no), with stratification by SEER age group (20–29, 30–39, and 40–49). Census tract poverty was defined as 20% or more of the population living below the poverty level for approximately 30 years. The investigators defined rurality using U.S. Department of Agriculture Rural-Urban Commuting Area codes. The Kaplan-Meier method with a log-rank test was applied for the statistical analysis, along with Cox proportional hazards regression models adjusting for multivariable confounders (ie, patient demographics, year of diagnosis, tumor characteristics, and initial treatment modality).
Key Results
Overall, the 5-year survival rate was highest in patients with early-onset colorectal cancer living in nonpoverty and nonrural areas (n = 46,566; 72%) and lowest in those living in impoverished areas with any degree of rurality (n = 6,480; 67%). The investigators noted some variation by age group, with a rate of 64% in those between the ages of 20 and 29 who lived in impoverished rural areas.
A multivariable analysis revealed that patients living in rural vs nonrural areas alone had a 1.1- to 1.4-fold increased risk of death from colorectal cancer at 5 years (20–29 years: hazard ratio [HR] = 1.35, 95% confidence interval [CI] = 1.06–1.71; 30–39 years: HR = 1.26, 95% CI = 1.13–1.41; 40–49 years: HR = 1.12, 95% CI = 1.06–1.19). Compared with patients living in nonrural areas, those living in areas marked by both poverty and rurality were found to experience a 1.1- to 1.5-fold increased risk of death from colorectal cancer (HR = 1.29, 95% CI = 1.18–1.42); according to the investigators, the estimate was notably high in the group between the ages of 30 and 39 (HR = 1.51, 95% CI = 1.22–1.88).
The investigators concluded: “Early-onset colorectal cancer is a rising concern nationwide, but underresourced areas face unique challenges. Our results can be used to inform health system policies for ongoing investments in cancer diagnosis and treatment resources in rural or impoverished areas for younger patients with colorectal cancer and their communities. These may include education programs to encourage healthy lifestyles, as well as symptom awareness campaigns tailored to young adults to improve earlier diagnosis.”
Meng-Han Tsai, PhD, of Augusta University, Georgia, is the corresponding author of the JAMA Network Open article.
Disclosure: The study was funded in part by a grant from the Georgia Cancer Center Paceline funding mechanism at Augusta University. For full disclosures of the study authors, visit jamanetwork.com.
