Allostatic load as a predictor of postoperative complications in patients with breast cancer.

Allostatic load (AL) is a biological measure of cumulative exposure to socioenvironmental stressors (e.g., poverty). This study aims to examine the association between allostatic load (AL) and postoperative complications (POC) among patients with breast cancer. Females ages 18+ with stage I-III breast cancer who received surgical management between 01/01/2012-12/31/2020 were identified in the Ohio State Cancer registry. The composite AL measure included biomarkers from the cardiovascular, metabolic, immune, and renal systems. High AL was defined as composite scores greater than the cohort's median (2.0). POC within 30 days of surgery were examined. Univariable and multivariable regression analysis examined the association between AL and POC. Among 4459 patients, 8.2% had POC. A higher percentage of patients with POC were unpartnered (POC 44.7% vs no POC 35.5%), government-insured (POC 48.2% vs no POC 38.3%) and had multiple comorbidities (POC 32% vs no POC 20%). Patients who developed POC were more likely to have undergone sentinel lymph node biopsy followed by axillary lymph node dissection (POC 51.2% vs no POC 44.6%). High AL was associated with 29% higher odds of POC (aOR 1.29, 95% CI 1.01-1.63). A one-point increase in AL was associated with 8% higher odds of POC (aOR 1.08, 95% CI 1.02-1.16) and a quartile increase in AL was associated with 13% increased odds of POC (aOR 1.13, 95% CI 1.01-1.26). Among patients undergoing breast cancer surgery, increased exposure to adverse socioenvironmental stressors, operationalized as AL, was associated with higher odds of postoperative complications.