Increased risk for colorectal cancer under age 50 in racial and ethnic minorities living in the United States

Abstract

Colorectal cancer (CRC) is the second most common cause of cancer death in USA. We analyzed CRC disparities in African Americans, Hispanics, Asians/Pacific Islanders, and American Indians/Alaska Natives compared to non-Hispanic Whites. Current guidelines recommend screening for CRC beginning at age 50. Using SEER (Surveillance, Epidemiology, and End Results) database 1973-2009 and North American Association of Central Cancer Registries (NAACCR) 1995-2009 dataset, we performed frequency and rate analysis on colorectal cancer demographics and incidence based on race/ethnicity. We also used the SEER database to analyze stage, grade, and survival based on race/ethnicity. Utilizing SEER database, the median age of CRC diagnosis is significantly less in Hispanics (66 years), Asians/Pacific Islanders (68 years), American Indians/Alaska Natives (64 years), and African Americans (64 years) compared to non-Hispanic whites (72 years). Twelve percent of Asians/Pacific Islanders, 15.4% Hispanics, 16.5% American Indians/Alaska Natives, and 11.9% African Americans with CRC are diagnosed at age <50 years compared to only 6.7% in non-Hispanic Whites (P < 0.0001). Minority groups have more advanced stages at diagnosis compared to non-Hispanic Whites. Trend analysis showed age-adjusted incidence rates of CRC diagnosed under the age of 50 years have significantly increased in all racial and ethnic groups but are stable in African Americans. These results were confirmed through analysis of NAACCR 1995-2009 dataset covering nearly the entire USA. A significantly higher proportion of minority groups in USA with CRC are diagnosed before age 50 compared to non-Hispanic Whites, documenting that these minority groups are at higher risk for early CRC. Further studies are needed to identify the causes and risk factors responsible for young onset CRC among minority groups and to develop intervention strategies including earlier CRC screening, among others.

Keywords: Alaska natives; American Indian; Asian American; Hispanics; SEER; cancer disparities; colorectal cancer.

Figure 1

Trend of Age‐Adjusted rate of CRC diagnosed under age 50 by race/ethnicity, SEER 13 Registries (1992+). Points are the observed values. Lines are the fitted values from the joinpoint regression model. Solid lines represent Annual Percent Change which differed significantly from 0 (P‐value < 0.05), whereas the dashed line represents insignificant difference from 0. Except among African Americans, all the race/ethnic groups have statistically significant (P‐value < 0.05) increase in rates under age 50. Each group differed significantly from the others as determined by pairwise comparisons for coincident trends at alpha = 0.05. AA: African American; AI/AN: American Indian/Alaska Native; NHW: Non‐Hispanic White; A/PI: Asian/Pacific Islander.