Pre-diagnostic biomarkers of metabolic dysregulation and cancer mortality

// Tomi Akinyemiju 1, 2, 3 , Justin Xavier Moore 1, 2 , Suzanne E. Judd 4 , Maria Pisu 2, 5 , Michael Goodman 6 , Virginia J. Howard 1 , Leann Long 4 , Monika Safford 7 , Susan C. Gilchrist 8 and Mary Cushman 9 1 Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA 2 Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA 3 Department of Epidemiology, University of Kentucky, Lexington, KY, USA 4 Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA 5 Division of Preventive Medicine, University of Alabama at Birmingham, Birmingham, AL, USA 6 Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA 7 Department of Medicine, Weill Cornell Medical College, New York, NY, USA 8 Department of Clinical Cancer Prevention and Cardiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA 9 Department of Medicine and Vermont Cancer Center, Larner College of Medicine at the University of Vermont, Burlington, VT, USA Correspondence to: Tomi Akinyemiju, email: tomiakin@uky.edu Keywords: metabolic biomarkers; cancer mortality; racial disparities; metabolism Received: January 18, 2018 Accepted: February 12, 2018 Epub: February 23, 2018 Published: March 23, 2018 ABSTRACT INTRODUCTION: The obesogenic milieu is a pro-tumorigenic environment that promotes tumor initiation, angiogenesis and metastasis. In this prospective cohort, we examined the association between pre-diagnostic metabolic biomarkers, plasma adiponectin, resistin, leptin and lipoprotein (a), and the risk of cancer mortality. METHODS: Prospective data was obtained from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort of Blacks and Whites followed from 2003 through 2012 for cancer mortality. We determined the association between metabolism biomarkers (log-transformed and tertiles) and risk of cancer mortality using Cox Proportional Hazards models with robust sandwich estimators to calculate the 95% confidence intervals (CIs), and adjusted for baseline covariates, including age, gender, income, education, physical activity, BMI, smoking status, alcohol use, and comorbidity score. RESULTS: Among 1764 participants with available biomarker data, each SD higher log-leptin was associated with a 54% reduced risk of total cancer mortality (HR: 0.46, 95% CI: 0.23 – 0.92) and obesity-related cancer mortality (HR: 0.55, 95% CI: 0.39-0.79). Among Blacks only, each SD higher log-resistin was associated with a nearly 7-fold increased risk of cancer mortality (adjusted HR: 6.68, 95% CI: 2.10 – 21.21). There were no significant associations of adiponectin or Lp(a) and cancer mortality. CONCLUSIONS: Leptin is involved in long-term regulation of energy balance, while resistin is involved in chronic inflammation and LDL production. These findings highlight the biological mechanisms linking metabolic dysregulation with cancer mortality, and the influence of resistin on cancer mortality only among Blacks suggests that this hormone may be a useful biomarker of racial differences in cancer mortality that deserves further study. IMPACT : Our observed increased risk of cancer mortality associated with higher serum resistin levels among Blacks suggests that if validated in larger cohorts, clinical strategies focused on resistin control may be a promising cancer prevention strategy.