Incidence and characteristics of young-onset colorectal cancer in the United States: An analysis of SEER data collected from 1988 to 2013.

BACKGROUND:The incidence of colorectal cancer (CRC) has significantly increased in adults < 50 years old who are below the screening age. OBJECTIVES:The primary objective was to evaluate the age-standardized incidence (ASI) of young-onset CRC from 1988 to 2013. The secondary objective was to assess factors associated with cancer-specific death (CSD). METHODS:We accessed data of 64,854 CRC patients (20-49 years old) from the United States Surveillance, Epidemiology, and End Results Program (SEER) database. RESULTS:A gradual increase in the ASI of CRC in the study population was found: from 3.59/100,000 males in 1988 to 5.21/100,000 males in 2013, and from 3.15/100,000 females in 1988 to 4.45/100,000 females in 2013. ASI adjusted by race revealed a relatively pronounced increase in the white population compared to African American and other races, with an increase from 3.07/100,000 persons in 1988 to 4.79/100,000 persons in 2013. Males had a 19% higher likelihood of CRC-related death compared to females [hazard ratio (HR) = 1.19, 95% confidence interval (CI): 1.16-1.23], and African American had a 1.34-fold higher likelihood of CRC-related death compared to whites (95% CI: 1.28-1.39). CRC-related death was significantly higher in patients with signet ring-cell histology (HR = 1.56, 95% CI: 1.45-1.68), compared to patients with adenocarcinoma. Male gender, and advanced stage predicted a higher likelihood of CRC-related death in African Americans compared to the whole population. Signet ring-cell histology, advanced stage, and advanced grade were significantly associated with CRC-related death in African-American patients. CONCLUSION:This study corroborates emerging data that the (ASI) of young-onset CRC is increasing. It also identified factors associated with cancer-specific death in this population that may aid in targeting screening strategies for adults < 50 years old.