Abstract C90: Colorectal cancer among Hispanics in the U.S.: Nativity disparities in stage at diagnosis and survival
Authors: Montealegre Jane R. , Zhou Renke , Amirian E. Susan , Scheurer Michael E. 
Published: May 2015

Introduction: Compared to non-Hispanic whites, Hispanics in the U.S. are significantly more likely to be diagnosed with late-stage colorectal cancer (CRC) and have a higher CRC-specific mortality hazard. While the low CRC screening rates among Hispanics (29%) are known to be lowest among foreign-born individuals (22%), few studies have examined CRC disparities by nativity. Here we examine differences in late-stage CRC diagnosis and survival among U.S.- and foreign-born Hispanics.

Methods: We used data from the Surveillance, Epidemiology, and End Results (SEER) program. Cases were Hispanic men and women diagnosed with primary invasive CRC between 1988 and 2008. Nativity was based on place of birth and was categorized as U.S.- versus foreign-born. Missing nativity values were imputed using multiple imputation by logistic regression, a strategy with high sensitivity (91%) and specificity (90%) for detecting foreign-born status. Distant and regional tumors were classified as late-stage; local tumors were classified as early-stage. Multivariable logistic regression was used to assess the association between late-stage diagnosis and nativity after adjusting for demographic characteristics (age at diagnosis and gender) and anatomic subsite (proximal, distal, rectum, or other). Multivariable Cox regression was used to assess the association between CRC-specific survival and nativity after adjusting for demographic characteristics, tumor characteristics (stage at diagnosis and anatomic subsite), and receipt of cancer-directed therapy (surgery and radiation).

Results: Fifty eight percent of cases of invasive CRC among Hispanics were diagnosed at a late stage and 63% of cases were among foreign-born individuals. Foreign-born Hispanics were significantly more likely than U.S.-born Hispanics to have a late-stage diagnosis after adjusting for demographic characteristics (adjusted odds ratio=1.08, p&lt;0.001). However, the demographics-adjusted mortality hazard was similar among foreign- and U.S.-born Hispanics (adjusted hazard ratio [AHR]=0.99, p-value=0.790). After adjusting for tumor characteristics, foreign-born Hispanics had improved survival compared to their U.S.-born counterparts (AHR=0.94, p=0.005). Their survival advantage remained significant after adjusting for both tumor characteristics and cancer-directed therapy (AHR=0.92, p&lt;0.001).

Conclusions: The increased prevalence of late-stage diagnosis among foreign-born Hispanics is likely a reflection of their reduced screening rates relative to Hispanics born in the U.S. However, the increased risk of late-stage diagnosis did not result in an increased mortality hazard among foreign-born Hispanics. In fact, survival was better among foreign- versus U.S.-born Hispanics after adjusting for stage at diagnosis and receipt of cancer-directed therapy. Similar patterns have been found for cervix and overall cancer survival and may be attributed to changes in risk profiles associated with acculturation (e.g., higher rates of smoking, obesity, alcohol consumption, and poor nutrition). Additionally, U.S.-born Hispanics have a higher prevalence of chronic diseases (e.g., diabetes, obesity, heart disease) that may negatively affect cancer survival. Our results suggest that the overlap between race/ethnicity and nativity status should not be overlooked in cancer health disparities research.

Citation Format: Jane R. Montealegre, Renke Zhou, E. Susan Amirian, Michael E. Scheurer. Colorectal cancer among Hispanics in the U.S.: Nativity disparities in stage at diagnosis and survival. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr C90. doi:10.1158/1538-7755.DISP13-C90