Epidemiology of Colorectal Cancer in Individuals Under 40 Years of Age: A Retrospective Study From the Explorys Database

Abstract

Introduction: Recent literature has demonstrated an increasing incidence of colorectal carcinoma in young patients. The aim of the study was to investigate the epidemiological characteristics of colorectal cancer (CRC) in patients under 40 years of age from the Explorys database. Methods: We queried a commercial database (Explorys Inc, Cleveland, OH), an aggregate of electronic health record (EHR) data from 23 major integrated U.S. healthcare systems from 1999 to May 2015. We identified an aggregated patient cohort of eligible patients with “Primary malignant neoplasm of the colon and/or Primary malignant neoplasm of rectum under 40 years of age”, based on Systemized Nomenclature Of Medicine - Clinical Terms (SNOMED-CT) codes. Tumors were classified into rightsided cancers (from the cecum to and including the splenic flexure), left-sided cancers (located in the descending and the sigmoid colon), and rectal cancers. Results: Of the 46,261,400 individuals in the database, we identified 2790 patients with CRC under 40 years of age with an overall prevalence of 14.3/100,000 persons. The prevalence was higher in Caucasians, (RR=3.76; 95% CI=3.48-4.07), African-Americans (RR 3.47; 95% CI: 3.13-3.85) and Asians (RR 3.59; 95% CI: 3.08-4.20), all with p < 0.0001. Compared to patients with CRC aged 40 and above, patients with CRC aged under 40 were more likely to have co-diagnoses of Crohn's (4.7% vs 1.1%), UC (2.9% vs 1.2%), history of renal transplant (0.7% vs 0.3%), HIV infection (1.8% vs 0.5%), FH of cancer (18.3% vs 11.4%) and FH of malignant neoplasm of GI tract (12.9% vs 6.8%), all with p < 0.0001. For subsite location of CRC, compared to patients with CRC aged 40 and above, patients with CRC aged under 40 were more likely to have rectal cancer (39.1% vs 35%, p < 0.0001), less likely to have right-sided cancer (15.8% vs 19.6%, p < 0.0001), and there was no statistically significant difference in distribution of left-sided cancer among the two groups. Conclusion: The estimated prevalence of CRC in individuals under 40 years of age in the US is 14.3/100,000 with predominance in Caucasian, African-American and Asian population. Compared to older patients, CRC patients under 40 years of age are more likely to have certain risk factors that should prompt early evaluation. Overall, patients with CRC under 40 years of age are more likely to have rectal cancer compared to patients with CRC aged 40 and above.