Insurance status and residential zip codes linked with survival among breast cancer patients

Reviewed by Emily Henderson, B.Sc.Mar 8 2022

Recent findings published in JAMA Oncology found that individual insurance status and residential zip codes were correlated with overall survival among women with early hormone receptor-positive breast cancer.

Additionally, the study found that Black women experienced shorter spans of time free of relapse, as well as overall survival compared with white women.

This study shows that where you live and what type of health insurance you have can matter. The findings also suggest that the disparities we see with mortality rates in Black and white women are not just one factor that’s predicting these outcomes, it’s social determinants of health. It's a mix of structural, individual and environmental factors that are predicting breast cancer outcomes."

Betina Yanez, PhD, associate professor of Medical Social Sciences and co-author of the study

Hormone receptor-positive breast cancer is characterized by breast cancer cells that contain either estrogen or progesterone proteins, or both. These receptors attach to substances in the blood to help increase tumor growth and metastasis. Endocrine hormone therapy is the standard course of treatment, in addition to surgery, radiation or chemotherapy.

While a small portion of patients with breast cancer are diagnosed as hormone-receptor positive, previous work has identified racial disparities in overall survival among Black women in the U.S. with hormone-receptor positive breast cancer. The association between social determinants of health on the individual- and neighborhood-levels, however, has not been well-studied in diverse populations of patients with breast cancer.

In the current study, investigators analyzed data from more than 9,700 women with hormone-receptor positive breast cancer who were enrolled in the National Cancer Institute's Trial Assigning Individualized Options for Treatment (TAILORx) breast cancer trial.

The investigators examined race and clinical outcomes, controlling for individual insurance coverage and neighborhood deprivation index, which was measured using individuals' residential zip codes.

Overall, Black women were found to have shorter relapse-free intervals and overall survival compared to white women, even after adjusting for social determinants of health and early discontinuation or non-initiation of endocrine hormone therapy and other clinicopathologic factors.

Additional post-hoc analysis revealed that patients with Medicare or Medicaid insurance had shorter overall survival compared to those with private insurance and patients living in neighborhoods with the highest neighborhood deprivation index score also experienced shorter overall survival, regardless of race.

"These findings indicate that there is a need to develop more nuanced, predictive models to better understand disparities in breast cancer," Yanez said. "Some social determinants of health are modifiable, some are not; and how we address select social determinants of health can be a health policy matter."