Abstract A54: Multisystemic biologic risk index and cancer mortality: Differences by age group and race/ethnicity
Authors: Acheampong Teofilia , Odegaard Andrew 
Published: February 2019

Background: Multisystemic biologic risk is a clinically meaningful and practical surrogate for allostatic load, a metric of health risk used to express shared physiologic variance in multiple biologic systems, based on the hypothesis that recurrent exposure to external stressors leads to progressive dysregulation. Allostatic load and proxies capture the complex biologic cascade that occurs in cardiovascular, metabolic, and immune domains in response to chronic environmental and psychosocial stress. Previous research has demonstrated positive associations between higher indices of multisystemic biologic risk and declining cognition, physical function, and increased cardiovascular disease and mortality risk. However, we are not aware of any research testing the association between an index of multisystemic biologic risk and cancer outcomes.

Aim: To examine the association of an index of multisystemic biologic risk (MSBRI) with cancer mortality using data from NHANES, and whether the association differed by race/ethnicity and age.

Methods: In 8,996 participants in the NHANES III (year 1989-94), age ≥ 40 years with complete data, we created an index of MSBRI using biomarkers from domains of cardiovascular (pulse rate, blood pressure), metabolic (HOMA-IR, triglycerides, waist circumference), and immune (white blood cell count, c-reactive protein, fibrinogen level). Participants were assigned a score for each biomarker informed by clinical cut points, or based upon evidence in the literature indicating a threshold of risk for disease, and each marker within each domain was scored 0 (low), 1 (moderate), and 2 (high); a higher score represents hypothesized higher risk (range 0-14). Cancer mortality was ascertained from linkage to the National Death Index and participants were followed until 2011. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CI) for overall cancer mortality risk with the MSBRI, adjusting for age, sex, education, income, U.S. region, insurance, physical activity, smoking, alcohol, and BMI. All models utilized the appropriate survey weights.

Results: There were 621 cancer deaths during follow-up. Non-Hispanic black, Mexican-Americans, and women (overall) had higher average levels of the MSBRI. On a per-unit basis of the MSBRI, the HR (95% CI) for cancer mortality was 1.11 (1.02-1.21) for each unit of increase in score. Additionally, there was evidence that the association may differ by race/ethnicity. Among the non-Hispanic white sample, the per-unit HR (95% CI) for the MSBRI was 1.06 (1.00-1.12), whereas the HR (95% CI) for non-Hispanic Black, Mexican American, and “Other” (all other race ethnicities not including the aforementioned groups) were, respectively, 1.04 (0.95-1.13), 1.07 (0.98-1.18), and 1.23 (1.07-1.42). There was also evidence that the association may differ by age. The HR (95% CI) was 1.09 (0.97-1.24) for participants &gt; 50 years of age, and 1.28 (1.05-1.56) for ages ≤ 50 years.

Conclusions: There was strong, positive association between a higher score on an index of multisystemic biologic risk (proxy for allostatic load) and risk for cancer mortality in the NHANES III follow-up cohort. The results also suggest that the association may differ by race/ethnicity and age. These results are some of the first to link a proxy for allostatic load with a major cancer outcome, and because the formulation of the index relied upon common clinical measures, this index may have clinical utility for cancer prediction and thus clinical and population cancer prevention strategies.

Citation Format: Teofilia Acheampong, Andrew Odegaard. Multisystemic biologic risk index and cancer mortality: Differences by age group and race/ethnicity [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A54.