The 5-year survival for younger adults with colorectal cancer improved for White patients alone between 1992 and 2013, according to a new analysis presented by Zaki et al at Digestive Disease Week 2022 (Abstract 895). However, no survival gains were found for Black, Hispanic, or Asian patients with early-onset colorectal cancer (diagnosed younger than age 50).
“Our most stunning finding was that even over a 20-year span, Black [patients] had not caught up to White [patients] in surviving early-onset colorectal cancer,” said Timothy Zaki, MD, the study’s lead author and an internal medicine resident physician at the University of Texas Southwestern Medical Center. “Survival for Black [patients] diagnosed from 2003 to 2013 remained even lower than for White [patients] diagnosed a decade earlier.”
Study Methods and Disparities Found
Using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program of cancer registries, the researchers identified 33,777 individuals newly diagnosed with early-onset colorectal cancer between January 1, 1992, and December 31, 2013. Of these, 58.5% were White, 14.5% were Hispanic, 14% were Black, and 13% were Asian.
They found that 5-year relative survival ranged from 69.1% for White patients to 57.6% for Black patients. Survival was lowest for Black men (56.5%) and highest for White women (70.6%). Even with localized disease, disparities persisted, with 94.2% of White patients vs 90.2% of Black patients surviving for 5 years.
“Our study’s identification of disparities among younger Hispanic and Asian adults adds to existing literature,” said Dr. Zaki. “However, we lack information, such as what treatment these individuals received, that could help explain the disparities, so we are still left with the question of why they exist.”
Disparities in colorectal cancer survival are well documented in older adults, but younger adults are a growing yet less-studied proportion of those diagnosed. Scientists are still seeking reasons for racial and ethnic disparities in this disease, but believe they may include employment; insurance status; income and education level; behaviors (eg, tobacco, alcohol, diet); environment (eg, rural or urban); social support; and cultural factors.
“With recommendations now that colorectal cancer screening start at age 45 vs 50, one concern is whether health disparities will worsen as a result,” said Dr. Zaki. “If more are screened who have the means and inclination to do so—but we fail to make progress in other populations—we could see these gaps widening.”
The researchers noted that this study’s findings may help inform research on interventions to address disparities in early-onset colorectal cancer, and they recommended that future studies explore social determinants of health and diagnostic and treatment differences that may contribute.
