LAUSR

The disease burden for colorectal cancer (CRC) varies considerably according to race and ethnicity. In the USA, African-Americans (AA) have the highest incidence of CRC and the lowest survival rates compared to other racial/ ethnic groups; Hispanics are diagnosed at later stages and have inferior survival compared to non-Hispanic whites [1]. Various factors, including adherence to CRC screening guidelines, are thought to contribute to the racial/ethnic differences in CRC incidence and mortality [2]. CRC is the second most commonly diagnosed cancer in US Hispanics. In Puerto Rico, CRC is the most diagnosed cancer when taking into account both men and women. Despite evidence that the overall CRC incidence rates have decreased, data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (SEER; http://seer. cancer.gov) show that Hispanic subgroups had increasing CRC incidence rates during 1992–2013. Moreover, CRC incidence rates across Hispanic subgroups vary, with Caribbean and South American Hispanics having higher CRC incidence rates than Central American Hispanics [3]. In this issue of Digestive Diseases and Sciences, the authors reported the prevalence of colorectal adenomas in a prospective cohort of US Hispanics undergoing screening colonoscopies in their catchment area [4]. Among the cohort examined, 30.6% had at least one adenoma, 23.5% had proximal adenomas, 12.0% had advanced adenomas, and 8.9% had proximal, advanced adenomas, with no significant differences across the Hispanic subpopulations (Puerto Ricans and Dominicans). Previous studies have reported similar adenoma rates for US Hispanics [5]. Nonetheless, despite a similar prevalence of adenomas between US Hispanics and non-Hispanic whites, CRC incidence rates remain lower among US Hispanics compared to US non-Hispanic whites and non-Hispanic blacks. This unexplained discrepancy between adenoma prevalence rates and CRC incidence suggests that unknown genetic/environmental factors may modify the adenomacarcinoma sequence among US Hispanics. Furthermore, incidence and mortality rates for CRC among US Hispanics are higher than the rates observed in their native countries, suggesting that environmental factors associated with acculturation to the USA may contribute to this increased risk [6]. In the current investigation by Chablani et al. [4], most of the US Hispanics in their cohort were of Puerto Rican and Dominican descent. Thus, their findings may be more applicable to US Hispanics from the Caribbean and may not represent the prevalence of adenomas among other US Hispanic subgroups. CRC incidence rates differ across US Hispanic subpopulations. For example, Hispanics of Puerto Rican and Cuban descent have been reported to have higher CRC incidence rates compared to Hispanics of Mexican descent [6]. Similarly, disparities in CRC mortality rates have also been observed among US Hispanics living in Florida, with higher mortality rates among men of Puerto Rican descent compared to men of Cuban and Mexican descent [7]. Differences in adenoma prevalence rates have also been observed among Hispanics living in Puerto Rico compared to those living in the USA, with higher rates of adenomas among Puerto Ricans in the USA [8]. Another important finding reported by Chablani et al. [4] was the high prevalence of proximal neoplasia observed among Hispanics of Puerto Rican and Dominican descent, & Marcia Cruz-Correa [email protected]