Body composition and allostatic load in racially and ethnically diverse patients with metastatic colorectal cancer.

Abstract

e15598 Background: Patients with metastatic colorectal cancer (mCRC) are living longer due to treatment advances; however, adverse phenotypes of body composition (BC) such as sarcopenia (SA) and myosteatosis are associated with lower survival. Allostatic load (AL), a measure of physiological stress, and neutrophil-to-lymphocyte ratio (NLR), a biomarker of chronic inflammation, are also linked to worse cancer outcomes. This study examines the relationship between adverse BC phenotypes and AL in Hispanics/Latinos (H/L) and Blacks/African Americans (B/AA) who are often disproportionately burdened with health disparities and chronic stress. Methods: A retrospective cross-sectional study of H/L and B/AA patients (n = 88) diagnosed with mCRC between 2008-2023 was conducted. The L3 slice of the CT used to diagnose metastatic disease was analyzed for skeletal muscle (SM; cm2) quantity and SM radiodensity (mean HU). SA, sarcopenic obesity (SO), and myosteatosis were identified using previously published sex-specific cut-points. AL score (0-9) was calculated using 9 physiologic biomarkers collected from the electronic medical record within 45 days of diagnosis. Elevated AL was defined as a total score ≥4. Mann-Whitney, Spearman correlation, and multivariable logistic regression assessed relationships of AL with sex, ethnoracial groups, and NLR. Data reported as median [IQR]. Results: The sample consisted of 51% men with a mean age of 61.8 ±15.18 years. 21.6% were H/L and 88.4% were B/AA. 67% had BMI > 30, 53.4% were sarcopenic, 35.2% classified as sarcopenic obese, and 43.2% had myosteatosis. H/L females had a higher prevalence of myosteatosis than H/L men (86% vs 17%, respectively, p = 0.0018) and B/AA men (32%, p = 0.0049). No differences in median values of body composition parameters between AL groups were observed (P > 0.05). A weak positive correlation between AL score and NLR was observed (rho = 0.38, p<0.0003). The elevated AL group had a higher median NLR (5.24 [3.09-10.93]) compared to those with low AL (3.65 [1.86-5.14]; p = 0.0029). SO was associated with higher AL score (3 [4-2] vs 2 [3-1], p = 0.025). Patients with myosteatosis had higher median AL scores compared to those without myosteatosis (3 [4-2] vs 2 [3-1], p = 0.0298). Odds of higher AL was associated with SO adjusting for age, sex, and race/ethnicity (OR =1.51 p = 0.02, 95% CI 1.05 - 2.16). Conclusions: Associations between AL score and NLR, SO, and myosteatosis suggest interlinks between chronic stress, inflammation, and unfavorable body composition in this patient population, all of which have been associated with poorer cancer outcomes. Further investigations to evaluate the combined impact of these factors on survival in this population are warranted.