Researchers at The Ohio State University Comprehensive Cancer Center—Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC-James) showed that chronic physiologic “wear and tear” from stress, known as allostatic load, may be associated with a decreased likelihood of cancer treatment completion and lower overall survival.
Samilia Obeng-Gyasi of OSUCCC-James presented these findings at the 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved, held online Oct. 6-8.
Allostatic load is caused by lifelong exposure to stressors—such as social isolation, poverty, and racism—many of which are common among racial/ethnic minorities.
“Patient behavior and clinical outcomes cannot be isolated from the effects of their social environment,” Obeng-Gyasi, a surgical oncologist and member of the Translational Therapeutics Research Program at the OSUCCC-James, said in a statement.
In this study, Obeng-Gyasi and colleagues in the ECOG-ACRIN Cancer Research Group sought to understand how allostatic load and genetic ancestry (identified by DNA) impact patients’ survival and their likelihood of completing chemotherapy. Prior studies suggest that allostatic load and genetic ancestry each play a role in poor breast cancer outcomes; however, no studies have looked at both factors at the same time in a study population.
This study represents a retrospective review of ECOG-ACRIN E5103, a clinical trial evaluating the inclusion of bevacizumab into adjuvant sequential anthracycline and paclitaxel in patients with lymph node-positive or high-risk lymph node-negative HER2-negative breast cancer.
The researchers analyzed data from the ECOG-ACRIN E5103 phase III clinical trial, one of the first large breast cancer treatment trials to assemble a biorepository and database of patient information, including demographics and DNA, for future research.
Using genomic analyses and other patient information from the E5103 repository, Obeng-Gyasi and colleagues examined chronic stress, measured by allostatic load, across three broad categories of genetic ancestry—African, European, and other. Among the 348 patients included in the analysis, approximately 80% had European ancestry, 10% had African ancestry, and 10% had other ancestry.
Allostatic load was measured in patients in E5103 using biomarkers of the cardiovascular, immune, and metabolic systems collected prior to starting treatment. Examples of these biomarkers included body-mass index, blood pressure, creatinine, and several cytokines.
After adjusting for genetic ancestry, the researchers found that each one unit increase in allostatic load score was associated with a 15% reduction in the likelihood of completing chemotherapy and a 14% increase in the risk of death.
Allostatic load appeared better than genetic ancestry at predicting chemotherapy completion and overall survival.
