Abstract PR12: Adolescent inflammation and body mass index in relation to colorectal cancer risk

Abstract

Inflammation and obesity in adulthood have been associated with risk of colorectal cancer (CRC); however, less is known about the role of early-life inflammation and body mass index (BMI) in relation to CRC risk. We therefore sought to evaluate these associations in a cohort of 239,464 Swedish men compulsorily enlisted in the military in late adolescence (ages 16-20 years). At the time of the conscription assessment (1969-1976), erythrocyte sedimentation rate (ESR) was assayed as a measure of inflammation and height and weight were measured. The conscription registry has been linked with national cancer and mortality registries, and men have been followed for CRC through January 1, 2010. Over an average of 35 years of follow-up, 885 cases of CRC occurred, including 501 colon cancers and 384 rectal cancers. Cox regression was used to estimate Hazard Ratios (HRs) and corresponding 95% Confidence Intervals (95% CIs) adjusted for covariates, including childhood socioeconomic status. Men with high inflammation (ESR ≥ 15 mm/hr) in late adolescence had 63% higher risk of CRC (HR: 1.63; 95% CI: 1.08, 2.46) than men with low inflammation (ESR <10 mm/hr) (p-trend: 0.006). This association did not significantly differ by anatomic site (p-difference: 0.50), though the trend was statistically significant for cancers of the colon only (p-trend: 0.009). Late-adolescent BMI was also significantly associated with CRC risk (p-trend: <0.001), with obese adolescents (BMI ≥ 30 kg/m2) experiencing a 2.37-fold higher risk of CRC (HR: 2.37; 95% CI: 1.50, 3.74) than their normal weight counterparts (BMI 18.5-<25 kg/m2). Again, the association between BMI and cancer risk did not significantly vary by anatomic site (p-difference: 0.40), although the trend was statistically significant for cancers of the colon only (p-trend: < 0.001). These analyses were mutually adjusted for BMI and ESR, suggesting that both adolescent inflammation and BMI may be independently associated with CRC risk. Future research is needed to better understand how life-course inflammation and BMI relate to colorectal cancer.

Citation Format: Elizabeth D. Kantor, Ruzan Udumyan, Lisa B. Signorello, Edward L. Giovannucci, Scott Montgomery, Katja Fall. Adolescent inflammation and body mass index in relation to colorectal cancer risk. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr PR12.