Racial/Ethnic Disparities in Survival Among Patients With Young-Onset Colorectal Cancer

Abstract

Purpose: Racial disparities in colorectal cancer (CRC) persist, despite overall reductions in morbidity and mortality. In addition, incidence is rising among individuals younger than 50 years of age. We compared the survival of young-onset CRC among non-Hispanic black (NHB), non-Hispanic white (NHW), and Hispanic individuals.

Patients and methods: Using the National Cancer Institute's Surveillance, Epidemiology, and End Results program data, we identified individuals between the ages of 20 and 49 years, diagnosed with CRC between 2000 and 2009. Survival rates and Cox proportional hazards models were used to compare stage-specific 5-year survival among NHBs, NHWs, and Hispanics.

Results: We identified 28,145 patients with young-onset CRC (19,497 NHW; 4,384 NHB; 4,264 Hispanic) during the 10-year study period. Overall survival at 5 years after CRC diagnosis was 54.9% among NHB, 68.1% among NHW, and 62.9% among Hispanic individuals (P < .001). NHB individuals had a significantly higher hazard of cancer-specific death compared with NHWs after adjusting for age, sex, race, stage, county-level poverty, and treatment history in cases of colon (hazard ratio [HR], 1.35; 95% CI 1.26 to 1.45) and rectum/rectosigmoid junction (HR, 1.51; 95% CI, 1.37 to 1.68) cancers, whereas there was no significant difference in survival between NHWs and Hispanics. The greatest racial disparities in cancer-specific survival were observed among NHB and NHW patients diagnosed with stage II cancers of the colon (HR, 1.69; 95% CI, 1.33 to 2.14) and stage III cancers of the rectum (HR, 1.98; 95% CI, 1.63 to 2.40).

Conclusion: Survival after CRC diagnosis at a young age is significantly worse among NHBs compared with NHWs, even among patients with early-stage disease. Further study is needed to determine whether differences in tumor biology and/or treatment are associated with racial disparities in outcomes, which would have implications for CRC treatment and prevention.

Fig 1.

Adjusted overall survival curves for young-onset (A) stage 0 to I, (B) stage II, (C) stage III, and (D) stage IV colon cancers. Covariates adjusted for include age (5-year groups), county-level poverty (quartiles), sex, surgery, and radiation therapy by race/ethnicity.

Fig 2.

Adjusted overall survival curves for young-onset (A) stage 0 to I, (B) stage II, (C) stage III, and (D) stage IV rectum/rectosigmoid cancers. Covariates adjusted for include age (5-year groups), county-level poverty (quartiles), sex, surgery, and radiation therapy by race/ethnicity.