Death Rates from Breast Cancer Linked to Neighborhood
Article Summary
- Breast cancer patients from disadvantaged neighborhoods have a higher mortality rate from the disease than patients from advantaged neighborhoods, according to a study led by Sylvester researchers.
- The disparity was observed after controlling for multiple known risk factors.
- Unknown neighborhood-linked factors contribute to differences in breast cancer outcomes, concluded the researchers.
Breast cancer patients from disadvantaged neighborhoods face a higher risk of dying than patients from advantaged, wealthier neighborhoods, according to a new study.
The data from the nationwide study, released April 18, dovetails with similar results from breast cancer patients in the Miami area, published last year.
“Even after controlling for multiple other variables, women living in disadvantaged neighborhoods still have disparate survival outcomes,“ said Neha Goel, M.D., M.P.H., a surgeon-scientist and social epidemiologist at Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, who led both studies.
Dr. Goel, also an assistant professor in the Miller School’s DeWitt Daughtry Family Department of Surgery, and her colleagues are now conducting research to find out what accounts for the differences in breast cancer survival.
Deep Data on Breast Cancer Survival Rates
The new study on survival rates examined de-identified data from 350,824 breast cancer patients, collected by the National Cancer Institute (NCI) from 2016 to 2018. The data captured information such as tumor treatment regimens and access to health insurance, as well as socioeconomic measurements from patient neighborhoods, at the census-tract level.
Neighborhood measurements included factors such as:
• Median household income
• House value
• Median rent
• Education index
• Percentage of residents who were working class or unemployed
The dataset was pulled from 21 geographic areas, representing 36.7% of the U.S. population.
Dr. Goel and her team found that neighborhood disparities remained even after accounting for race and other factors known to affect outcomes, including access to health insurance, stage of cancer at diagnosis and type of treatment.
After crunching the numbers and controlling for known factors, they report that patients from the most disadvantaged neighborhoods had about a 40% higher risk of dying from the disease than patients from the most advantaged neighborhoods.
The new study was published in the Journal of the American Medical Association (JAMA) Network Open. While other studies have shown that neighborhood disadvantage can affect cancer outcomes, this study covered a larger geographic area and assessed a broader patient population, said Dr. Goel.
The new study also highlights the power of giant datasets like the NCI’s.
“They allow us to look closer at findings we first identify locally and validate them nationally,” said Dr. Goel.
That’s just what Dr. Goel did, tapping into the NCI database after first studying populations in the Miami area and reporting neighborhood-related differences in breast cancer mortality. That earlier study was also published in JAMA Network Open.
Unknown Factors Impacting Cancer Outcomes
The new findings have limitations, caution the researchers. It’s possible that the NCI dataset didn’t capture all characteristics that can affect outcomes, they note. Other individual, tumor and treatment measures might still come into play, such as trust in health care practitioners.
Dr. Goel thinks there may also be something about where people live that affects the outcome.
“Even after controlling for all these factors that we know are associated with disparities in breast cancer survival, there’s a residual disparity,” said Dr. Goel. “That disparity is associated with neighborhood-level disadvantage.”
Last year’s study on Miami-area neighborhoods ruled out a major contribution from air pollution. But there may be other environmental factors, such as exposure to toxins from contaminated sites that could play a role, she speculated.
Dr. Goel is investigating another potential factor: higher levels of stress in people living in disadvantaged neighborhoods. After all, poverty is associated with elevated stress levels, and some studies have hinted at a link between stress and breast cancer biology.
In their new research, Dr. Goel and her colleagues are examining genome-level changes in tumor biology that correlate with stress and other factors and linking them with neighborhood data.
“My lab is taking a ‘zip code to genomic code’ approach to understand how where one lives can impact tumor biology and ultimately breast cancer outcomes,” said Dr. Goel.
Tags: breast cancer, Dr. Neha Goel, Health Equity, Sylvester Comprehensive Cancer Center