Appalachians have a 5 percent higher incidence of malignant brain tumors and other central nervous system tumors than the rest of the U.S.
That’s according to a recent study published in the Journal of Neuro-Oncology. The study also found a higher mortality rate in the region due to these tumors and poorer survival rates.
A potential contributing factor to these higher rates? Access to health care.
“Brain tumors, especially malignant brain tumors, are often treated at academic medical centers or large, highly specialized medical centers,” Quinn Ostrom, a researcher on the study, said. “Depending on where you live, you may not be able to access the kind of highly trained surgeons that specialize in these kinds of tumors.”
A great many people throughout Appalachia live far from those speciality services that aid in treatment and recovery.
Ostrom is a postdoctoral associate at Baylor College of Medicine and a member of the Central Brain Tumor Registry of the United States, which has data on every brain tumor diagnosed in the country in the past 15 years.
Ostrom said the organization has been exploring how regional differences might point to health disparities. Appalachia was chosen because of a range of health disparities in the region in relation to the rest of the country, including obesity, diabetes and other cancer-associated risk factors.
Appalachia has a larger white non-Hispanic population compared to the rest of the country, Ostrom pointed out, which is the population with the highest malignant brain tumor incidence – about twice as high as among African-Americans and higher than Hispanics.
An examination of health insurance produced one of the study’s surprises.
The researchers found that while in the rest of the country the highest survival rate for people with malignant brain tumors is with those who have private health insurance, in Appalachia better survival outcomes are found in those who have Medicaid.
In Appalachia, “there was a survival advantage to being within the Medicaid system,” Ostrom said, “which we found surprising.” She and her colleagues believe this could be a consequence of people being unable to meet their private insurance copays or deductibles.
The incidence of malignant, or cancerous, brain tumors was higher for both males and females in Appalachia. The rate among males was higher than females, which is reflected in the general population.
The study found a heightened incidence for all age groups in Appalachia. This follows a 2017 study conducted by the University of Kentucky that found Appalachian children are at a significantly increased risk of low-grade brain tumors.
Researchers at UK write that genetics may play a role, but added that environmental factors “may also contribute to the increased risk of brain tumor development in Appalachia.” They note that while the role of carcinogens in the cause of brain tumors is controversial, limited studies have indicated factors that are prevalent in Appalachia, including smoking and pollution.
Ostrom and her colleagues found the highest rates of malignant brain tumors in central and northern Appalachia. The variations in regions within Appalachia, Ostrom suggested, could be attributed to the varying percentages of white non-Hispanics from one region to another, varying access to health care and insurance patterns.
The researchers explored non-malignant brain tumors as well, and found an incidence that is 3 percent lower than the rest of the country.
“At first, we were somewhat surprised by that,” Ostrom said. “But there are a couple of factors that we think can complicate the story.”
Benign tumors often go much longer without being diagnosed, she explained, because the symptoms tend to be milder, and poor access to health care may mean that a significant number of these tumors remain undiagnosed.
Ostrom said that a number of research projects are being considered as follow-up to this study. The researchers hope to further explore the role that socioeconomic status plays in the incidence and outcomes of brain tumors, and to look in more detail at the significance of proximity to urban areas and specialized medical centers.
“I think there should be more research on access to care and on populations that might not have access to the types of treatment that would increase their survival, or, in the case of non-malignant tumors, increase their quality of life,” Ostrom said.
They also hope to further examine the genetic factors that might explain differences in risk.
“Large studies like this can point researchers to unexpected variables that merit further investigation,” said Dr. Jill S. Barnholtz-Sloan of the Case Western Reserve University School of Medicine and a mentor to Ostrom. “These multifaceted lines of inquiry are critical for us to better understand this disease.”