291 Characteristics Associated With Young Colorectal Cancer in the United States

Abstract

INTRODUCTION: The incidence of young colorectal cancer (20–49 years) has been rising since the early 1990s and the American Cancer Society has recommended that we lower the age of screening colonoscopy to 45. There is much debate about whether the incidence is truly rising or whether it is impacted by earlier screening in predisposed individuals. We aimed to study the factors which predict presentation of colorectal cancer at a younger age as compared to older patients aged above 50 years. METHODS: The SEER 18 database was queried for colorectal cancer cases from 1990 to 2016. Cases were classified into young (20–49 years) and old (≥50 years), and multinomial logistic regression was used to predict the race/ethnicity, gender and tumor characteristics that were more likely with younger patients as compared to older patients. RESULTS: 818,621 total cases were reported. Analyses demonstrated that females were more likely than males to have colorectal cancer at a younger age (OR 1.055, CI 1.039–1.071). Non-Hispanic blacks were more likely than non-Hispanic whites to have younger age cancer (1.637, 1.383–1.937). Spanish Hispanic Latinos were more likely to have young cancer than non-Spanish Hispanic Latinos (2.128, 2.08–2.177). Indians/Pakistanis were more likely (1.277, 1.085–1.503) whereas Chinese (0.546, 0.495–0.602) and Japanese (0.372, 0.334–0.414) were less likely to have young cancer when compared to whites. Stage IV and III (1.586, 1.523–1.651; 1.575, 1.515–1.637) were more likely with young cancer than Stage I. Tumor sites such as rectum (1.351, 1.323–1.381) were more likely whereas ascending colon (0.511, 0.495–0.527) and hepatic flexure (0.627, 0.597–0.658) were less likely to have young cancer than the sigmoid colon. CONCLUSION: Race/ethnicity, gender, tumor stage/site as well as grade/histology were found to predict colorectal cancer at a younger age as compared to older patients. Younger patients had higher chances of advanced cancer (Stage IV/III) at presentation compared to older patients possibly due to prophylactic screening of patients above 50 years. Colorectal cancer is common at the sigmoid colon; but rectum and rectosigmoid junction were associated more with young cancer while other sites like cecum, ascending colon, hepatic flexure and transverse colon were less likely to be young than old cancer. Studies based on stratifying these and other risk factors may provide clues to the rising incidence of young colorectal cancer, and further recommendations maybe made for screening colonoscopy at younger ages.