# Allostatic Load as a Predictor of Postoperative Complications in Patients with Breast Cancer

## TL;DR

This study shows that higher levels of stress, measured as allostatic load, are linked to more post-surgery complications in breast cancer patients.

## Contribution

The study introduces allostatic load as a novel predictor of postoperative complications in breast cancer surgery.

## Key findings

- High allostatic load was associated with 29% higher odds of postoperative complications.
- A one-point increase in allostatic load was linked to 8% higher odds of complications.
- Patients with complications were more likely to be unpartnered, government-insured, and have multiple comorbidities.

## Abstract

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.

Assigned females at birth 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 4,459 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.