Association of lifestyle-related risk factors with incidence and mortality rates of colorectal cancer among adolescents and young adults (AYA) in the United States.

80 Background: Incidence of colorectal cancer (CRC) among adolescents and young adults (AYA) is increasing. A significant proportion of adolescents and young adults (AYA) with colorectal cancer (CRC) lack traceable genetic risk factors. We sought to study the impact of lifestyle-related risk factors on the incidence and mortality of CRC in these patients. Methods: We extracted data on crude incidence and mortality rates of CRC (reported per 100,000 population) for ages 15-39 years in all 50 U.S. states and District of Columbia from the Center for Disease Control (CDC) WONDER database (1999-2018). Data on risk factors such as obesity, physical activity, alcohol and tobacco abuse and nutrition were obtained from the Behavioral Risk Factor Surveillance System (BRFSS, 2020). Correlations were analyzed using Pearson’s co-efficient. p < 0.05 was considered statistically significant. Statistical analysis was performed using VassarStats. Results: Median crude incidence and mortality rates of CRC in AYA in the US from 1999-2018 were 3.8 (IQR 3.2, 4.4) and 0.7 (IQR 0.5,0.9) per 100,000 population respectively. States with higher age-adjusted prevalence of obesity per 100,000 had higher incidence (r = 0.36, p = 0.01) and mortality rates (r = 0.49, p = 0.0002) of CRC in AYA population. States with a higher age-adjusted prevalence of adherence to recommended weekly aerobic activity had lower incidence (r = -0.4515, p = 0.001) and mortality (r = -0.569, p < 0.0001) rates. While states with higher age-adjusted prevalence of tobacco abuse had higher incidence rate of CRC (r = 0.33, p = 0.02), there was no correlation with mortality rates (r = 0.24, p = 0.09). Higher prevalence of alcohol consumption was associated with decreased mortality rate (r = -0.44, p = 0.001), with no impact on incidence rate (r = -0.16, p = 0.26). States with lower daily consumption of fruits had higher incidence (r = 0.37, p = 0.01) and mortality rates (r = 0.59, p < 0.0001). No correlation of daily consumption of vegetables with incidence (r = -0.1516, p = 0.29) and mortality (r = 0.18, p = 0.22) rates was noted. Conclusions: In the current analysis, higher prevalence of obesity, lower rates of aerobic activity and lower daily consumption of fruits were strongly associated with increased incidence and mortality rates. The impact of tobacco abuse and alcohol consumption was more variable. Apart from improving access to genetic testing and counseling, efforts aimed at mitigating the rise of CRC incidence among AYA should also focus on traditional lifestyle-related risk factors.