Association of Allostatic Load With Overall Mortality Among Patients With Metastatic Non–Small Cell Lung Cancer

Abstract

ImportanceAdverse social determinants of health (SDHs) (eg, poverty) are associated with poor oncologic outcomes among patients with lung cancer. However, no studies have evaluated biological correlates of adverse SDHs, operationalized as allostatic load (AL), with mortality due to lung cancer.ObjectiveTo examine the association among AL, SDHs, and mortality among patients with metastatic non–small cell lung cancer (NSCLC).Design, Setting, and ParticipantsThis cross-sectional study of an observational cohort was performed at a National Cancer Institute–designated comprehensive cancer center with data accrued from June 1, 2017, to August 31, 2019. Patients with metastatic (stage IV) NSCLC enrolled at diagnosis into a prospective observational cohort study were included in the present analysis if they had all the biomarkers to calculate an AL score (N = 143). Follow-up was completed on August 31, 2021, and data were analyzed from July 1 to September 30, 2021.ExposuresSocial determinants of health.Main Outcomes and MeasuresOverall mortality and AL.ResultsA total of 143 patients met the study criteria with a median age of 63 (IQR, 55-71) years (89 men [62.2%] and 54 women [37.8%]). In terms of race and ethnicity, 1 patient (0.7%) was Asian, 7 (4.9%) were Black, 117 (81.8%) were White, 17 (11.9%) were of multiple races, and 1 (0.7%) was of other race or ethnicity. The mean (SD) AL was 2.90 (1.37). Elevated AL covaried with lower educational level (r = −0.26; P = .002), male sex (r = 0.19; P = .02), limited mobility (r = 0.19; P = .04), worsening self-care (r = 0.30; P < .001), problems engaging in usual activities (r = 0.21; P = .01), depressive symptoms (r = 0.23; P = .005), and a high number of stressful life events (r = 0.30; P < .001). Multivariable analysis found only increasing difficulty with mobility (r = 0.37 [95% CI, 0.13-0.60]; P = .002) and male sex (r = 0.63 [95% CI, 0.19-1.08]; P = .005) associated with higher AL. On adjusted analysis, elevated AL (hazard ratio, 1.43 [95% CI, 1.16-1.79]; P = .001) and low educational level (hazard ratio, 2.11 [95% CI, 1.03-4.34]; P = .04) were associated with worse overall mortality.Conclusions and RelevanceThe findings of this cross-sectional study suggest that higher AL was associated with adverse SDHs and worse overall mortality among patients with advanced NSCLC. These results provide a framework for replication and further studies of AL as a biological correlate for SDH and future prognostic marker.