(ChemotherapyAdvisor) – Colorectal cancer (CRC) incidence is more common in lower-socioeconomic status (SES) African-American and non-Hispanic white populations, but among Hispanics, that relationship is turned on its head, with higher-socioeconomic-status Hispanics facing a higher incidence of CRC than others, according to a study published in Cancer Epidemiology, Biomarkers & Prevention.
An analysis of data from the California Cancer Registry revealed significantly positive incidence rate ratios between SES and CRC incidence rates for Hispanics but no other ethnicity (Incidence Rate Ratio [IRR] SES Q5 v. Q1=1.54; 95% confidence interval [CI]: 1.39-1.69), reported senior author Iona Cheng, Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, and coauthors.
Lower CRC mortality rates among high-SES blacks and non-Hispanic whites are attributable to better access to health care and screening services, and higher rates of participation in colonoscopy screenings in which high-risk, early-stage adenomas are removed, the authors wrote.
The causes of the significant positive association between CRC and SES among Hispanics are not as clear.
“Prior studies have similarly found that U.S. Hispanics have lower mortality rates than non-Hispanic whites, despite lower income and less education,” the authors noted. “Possible explanations for this ‘Hispanic paradox’ have been attributed to healthier Latinos migrating to the U.S., the return of Hispanics to their native country to die in one’s birthplace, and/or better social support resulting in improved health outcomes.”
More affluent Hispanics in California may have adopted more typically American patterns of physical inactivity, obesity, and increased red meat consumption, the authors note – all of which are CRC risk factors.
“Supporting this hypothesis are sub-analyses of a neighborhood ethnic enclave index (comprised of language- and immigration-related census variables), in which we found that Hispanics living in more acculturated neighborhoods had higher incidence rates of CRC than those living in lower acculturation neighborhoods (highest to lowest quintile incidence rate per 100,000: Q5=148.7; Q4=138.7; Q3=131.6; Q2=118.3; Q1=94.9),” they reported.