A study published in JAMA Network Open indicated that screening, particularly with colonoscopy, is significantly associated with reduced risk of colorectal cancer (CRC) and mortality; however, test rates among African American individuals and those with low socioeconomic status were notably lower.
Researchers indicated that the disparities experienced by these individuals could be applicable to other underserved populations as well and could be lessened by improving access to and uptake of CRC screening.
“Our study results suggest that efforts in public health may improve CRC screening rates with implementation strategies that focus on these high-risk groups and that aim to lower barriers to CRC screening,” the authors wrote. “These barriers include limited access to gastroenterologists to perform screening or diagnostic colonoscopy and cost-prohibitive out-of-pocket expenses.”
Using data from the Southern Community Cohort Study, researchers assessed 47,596 participants who were eligible for CRC screening. The median baseline age was 54 years (interquartile range, 10 years), and the majority of individuals were African American (67.6%), female (60.7%), with a household income of <$15,000 (54.8%).
A total of 24,432 (63.9%) individuals had never undergone CRC testing at baseline. The CRC testing assessed at baseline and during follow-up interviews was associated with significant CRC risk reduction (hazard ratio [HR], 0.55; 95% CI, 0.44-0.70).
The results were similar in analyses stratified by race (African American: HR, 0.65; 95% CI, 0.50-0.85; white: HR, 0.44; 95% CI, 0.27-0.70) and household income (<$15,000: HR, 0.63; 95% CI, 0.46-0.86; ≥$15,000: HR, 0.49; 95% CI, 0.35-0.69). Sigmoidoscopy at baseline was associated with CRC risk reduction (HR, 0.75; 95% CI, 0.57-0.98). Inverse associations were also observed between CRC mortality and receipt of colonoscopy among women and men ([HR, 0.39; 95% CI, 0.21-0.73] vs [HR, 0.69; 95% CI, 0.40-1.18], respectively) and sigmoidoscopy ([HR, 0.37; 95% CI, 0.16-0.85] vs [HR, 0.82; 95% CI, 0.46-1.47]). However, this association did not extend to fecal occult blood test ([HR, 1.02; 95% CI, 0.62-1.70] vs [HR, 1.03; 95% CI, 0.55-1.93], respectively).
“Our findings suggest that increasing uptake of CRC screening among African American individuals may reduce the sizable racial disparity in CRC incidence and mortality,” the authors wrote. “In general, African American individuals, individuals with lower household income, and uninsured individuals are less likely to be concordant with CRC screening guidelines.”
Additionally, access to and use of healthcare could play a more prominent role in CRC racial disparities than other risk factors, as observed in other trials. The lack of patients able to afford insurance cost sharing and the logistical complications associated with transportation and scheduling have been hypothesized to contribute to the lesser rates of follow-up healthcare after abnormal CRC screening findings.
Furthermore, researchers indicated that lowering financial barriers and increasing access to CRC screening for the uninsured and underinsured might increase participation in screening and ultimately reduce CRC racial and socioeconomic disparities in incidence and mortality.
CRC is the fourth most commonly diagnosed cancer in the US and second-leading cause of cancer death, according to the study. Given the varying outcomes by race and socioeconomic status, the research presented in this study further highlights the importance of eradicating impediments for this population.
Andersen SW, Blot WJ, Lipworth L, Steinwandel M, Murff HJ, Zheng W. Association of Race and Socioeconomic Status With Colorectal Cancer Screening, Colorectal Cancer Risk, and Mortality in Southern US Adults. JAMA Network Open. doi:10.1001/jamanetworkopen.2019.17995.