Lung cancer in Black men in Chicago may be linked to stress, crime rates

The stress of living in neighborhoods with high rates of violent crime may be driving the high rate of lung cancer among Black men compared with white men, according to a new study from the University of Illinois Chicago.

This could help explain why Black men are more likely to get lung cancer even though, on average, they smoke less and start smoking later in life than white men.

The paper builds on earlier research from senior author Sage Kim, a professor of health policy and administration at UIC’s School of Public Health. That research found that Black men living in Chicago ZIP codes with higher violent crime rates had substantially higher levels of cortisol in their hair — an indicator of chronic stress — than those in areas with less violent crime. And while other research has linked chronic exposure to stress to poorer outcomes in cancer patients, “there’s very little literature linking the stress response to lung cancer,” Kim said.

So Kim, who is co-lead of the Cancer Prevention and Control program at the University of Illinois Cancer Center at UIC, teamed up with Zeynep Madak-Erdogan at the University of Illinois Urbana-Champaign and others to explore how living in neighborhoods with high levels of violence affects stress levels and lung cancer tumors. The researchers used homicide rates as an indicator of neighborhood violence.

They found that “chronic exposure to neighborhood social stress, such as violence, has biophysical consequences.” Kim said.

The study, published in Cancer Research Communications, focused on glucocorticoids, a group of steroid hormones that includes cortisol. These hormones bind to receptors that regulate the activity of other genes.

The researchers first assessed patterns of gene expression in lung cancer tumors and in cancer-free lung tissue from people living in different Chicago ZIP codes. They also determined where the glucocorticoid receptors bound to DNA in those tissues.

The analyses revealed that overall, glucocorticoid-receptor binding was highest in people who lived in high-violence areas. But within tumor tissues, those living in high-crime ZIP codes had lower binding. They also had lower levels of glucocorticoid receptor-regulated genes in the tumor tissues. The study accounted for other factors, such as poverty, that might lead to worse health outcomes in people living in high-crime areas, Kim said. 

“In terms of the genes the receptors regulated in the tumors of individuals living in high-violence areas, they were genes related to inflammation, higher proliferation, higher growth-factor signaling — all of which will lead to the worst outcomes for lung cancer,” Madak-Erdogan said. The findings suggest that glucocorticoids and glucocorticoid receptors are a primary driver of adverse tumor outcomes in those living with chronically high levels of environmental stress, she said. 

The study’s other authors include first author Hannah Heath, a doctoral student at UIUC; Abeer Mahmoud, an assistant professor in UIC’s College of Applied Health Sciences; and others at Columbia University and Virginia Commonwealth University.  

This article was adapted from a news release by Diana Yates at UIUC.