Abstract 5056: Exercise and inflammation on the risk of cancer
Authors: Marshall Catherine Handy , Dardari Zeina , Cainzos-Achirica Miguel , Mortensen Martin B. , Nasir Khurram , Al-Mallah Mouaz H. , Miedema Michael D. , Blankstein Ron , Blumenthal Roger S. , Visvanathan Kala , Blaha Michael J. 
Published: August 2019

Introduction: High systemic inflammation and low levels of exercise are associated with increased risk of cancer. We hypothesized that in the setting of inflammation, exercise mitigates cancer risk.

Methods: To address this, we identified 6,388 participants, free of cancer and cardiovascular disease, enrolled in the Multi-Ethnic Study of Atherosclerosis. Regular moderate/vigorous intentional exercise was categorized as present or absent based on self-report from validated questions. A composite inflammatory score was created with a point given for C-reactive protein, IL-6, fibrinogen, and GlycA above normal, with composite scores &gt; 2 points categorized as high. Cancer incidence was ascertained based on ICD codes abstracted from hospitalization or cancer registry data. Cox proportional hazard models were used to calculate subsequent risk of incident cancer. Models were adjusted for baseline age, gender, race, pack years smoking, education, income, health insurance status, body mass index, high-density lipoprotein levels, healthy diet adherence, statin and aspirin use.

Results: The mean age was 62 years (±10.2 years), 53% female, 39% white, 26% black, 22% Hispanic, and 12% Chinese-American. Compared to the reference group (individuals reporting no exercise and with low levels of inflammation), in multi-variable adjusted models, individuals with high levels of inflammation and no exercise were at highest risk of cancer (hazard ratio = 1.17; 95% confidence interval 1.00 – 1.37), while those with low levels of inflammation who exercised were at the lowest risk of cancer (HR 0.80, 95% CI 0.68-0.95). Those who had high levels of inflammation, but regular exercise had no increased risk of cancer (HR 0.94, 95% CI 0.68-1.30). There was no significant interaction between exercise and inflammation. When considering individual inflammatory markers, there was a similar pattern (Table).

Conclusion: Intentional moderate/vigorous exercise may lower the risk of cancer in individuals with high versus low levels of chronic inflammation.

Cox proportional hazard models for incident cancer by exercise and measures of inflammation, adjusteno exerciseany exerciseHR95% CIHR95% CILow composite score (0 - 1)Ref0.800.680.95High composite score (&gt;2)1.171.001.370.940.681.30P for interaction = 0.25Low CRP (&lt;2 mg/L)Ref0.800.680.95High CRP (&gt;2 mg/L)1.231.051.430.980.711.35P for interaction = 0.94Low IL-6 (&lt; 1.8 pg/mL)Ref0.800.680.95High IL-6 (&gt;1.8 pg/mL)1.070.911.260.860.621.19P for interaction = 0.18Low GlycA (&lt;400 µmol/L)Ref0.800.680.95High GlycA (&gt;400 µmol/L)1.191.021.390.960.691.32P for interaction = 0.73Low fibrinogen (&lt;450 mg/dL)Ref0.800.680.95High fibrinogen (&gt;450 mg/dL)0.970.751.250.770.511.18P for interaction = 1.00

Citation Format: Catherine Handy Marshall, Zeina Dardari, Miguel Cainzos-Achirica, Martin B. Mortensen, Khurram Nasir, Mouaz H. Al-Mallah, Michael D. Miedema, Ron Blankstein, Roger S. Blumenthal, Kala Visvanathan, Michael J. Blaha. Exercise and inflammation on the risk of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5056.