A new study from the University of Virginia reveals that allostatic load—the cumulative “wear and tear” the body experiences from chronic stress—plays a critical role in breast cancer outcomes and may help explain racial and geographic disparities in survival.
Allostatic load is measured through biomarkers that track how stress disrupts multiple systems, including cardiovascular, metabolic, kidney, and immune function. When these systems are strained over time, the body becomes less able to recover, leaving individuals more vulnerable to disease.
Researchers followed more than 3,000 women with stage I to III breast cancer. Black women had the highest average allostatic load scores, especially those living in rural areas. Rural Black women also faced the greatest mortality risk: each unit increase in their allostatic load score was linked to more than triple the risk of death compared to urban White women.
Overall, patients with higher scores had significantly worse survival outcomes. Even after adjusting for age, socioeconomic status, tumor stage, and treatment factors, a high allostatic load was associated with a 27 percent greater risk of death.
The study highlights how structural inequities—such as racism, poverty, and geographic isolation—directly influence biology. By embedding chronic stress into the body, these inequities accelerate health decline and worsen cancer survival. The authors stress that interventions addressing stress and its biological effects could be as vital as improving access to care in reducing disparities.
See: “Allostatic Load and Racial and Rural Disparities in Breast Cancer Survival” (August 21, 2025)
