Racial disparities found in early-onset colon cancer survival rates

Between 1992 and 2013, survival rates for young adults with colorectal cancer (CRC) improved for Caucasian patients – no increase was seen for those from Black, Hispanic or Asian communities

Using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program of cancer registries, researchers from the American Gastroenterological Association, identified 33,777 individuals newly diagnosed with early-onset CRC between January 1, 1992, and December 31, 2013. Of these, 58.5% were White; 14.5% Hispanic; 14% Black and 13% Asian.

How does examining the rates of colon cancer highlight ethnic disparities?

20 years, yet still no improvement on survival rates

“Our most stunning finding was that even over a 20-year span, [black patients] had not caught up in surviving early-onset CRC,” said Dr. Timothy Zaki, 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 [Caucasian patients] diagnosed a decade earlier.

Five-year survival for younger adults (those diagnosed before 50) was recorded mainly only for white patients. The team recorded the five-year relative survival ranged from 69.1 percent for white patients to 57.6 percent for Black patients.

Survival was lowest for Black men (56.5%) and highest for white women (70.6%). Even with localised disease the disparities persisted, with 94.2% of white patients versus 90.2% of black patients seeing five-year survival.

Uncovering and drawing attention to ongoing racial disparities

Disparities in CRC survival are well documented in older adults, but younger adults are a growing yet less-studied proportion of those diagnosed.

“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.”

The team from the American Gastroenterological Association are still seeking reasons for racial and ethnic disparities in this disease, but believe they may include employment, insurance status, income and education level, behaviours (e.g., tobacco, alcohol, diet), environment (e.g., rural or urban), social support and cultural factors.

“With recommendations now that CRC screening start at age 45 versus 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 CRC, and they recommended that future studies explore social determinants of health and diagnostic and treatment differences that may contribute.