Sarah Gehlert doesn’t need a microscope to figure out your odds of surviving cancer, she can tell from the house and neighborhood you live in.

Since 2003, the director of the Center for Interdisciplinary Health Disparities Research in Chicago has been leading a team of social, behavioral and biological researchers in exploring the reason why, despite the fact that white women are more likely to develop breast cancer, black women are more likely to die from the disease.

By studying how social and psychological factors influence disease in lab rats and following a cohort of black women with breast cancer living in predominantly black neighborhoods of Chicago’s South Side, Gehlert and her team have developed a plausible explanation for the disparity: Social isolation, vigilance and depression caused by stressors in the environment alter the genes of cancer cells, promoting tumor growth and ferocity.

Gehlert, who’s also a professor of social work at Washington University in St. Louis and president of the Society for Social Work and Research, presented her team’s findings in December at the National Institute of Health’s Behavioral and Social Sciences Lecture series in Rockville, Md. She’s the first social work researcher to be selected for the prestigious series that began in 1995.

There, she explained that the women in her study who lived in neighborhoods plagued by higher rates of violence, homicides, robberies and unsafe housing, for example, were more likely than women in more tranquil parts of the city to experience depression, loneliness, sexual assault or dislocation — all of which increase the presence of the stress hormone glucocorticoid in the body, resulting in a state of near-constant stress.

Normally, sporadic mutations of breast cancer and other cells occur throughout the lifespan, but are repaired through a process called apoptosis, or programmed cell death. However, Gehlert’s team found that more invasive tumors are rich in glucocorticoid receptors, the activation of which is associated with the failure of apoptosis, which ultimately results in cancer cell survival.

Her team’s “downward causal model” of explaining how the environment affects the expression of genes could explain other health disparities, perhaps to the perturbation of those who firmly believe diseases arise from the genome.

It’s not as simple as nature versus nurture, Gehlert said in an interview with NASW News. “We now know that it’s really the case that the genome is shaped by the person’s environment and is constantly adapting to the environment — a very social work-friendly way of looking at it,” she said.

Closing the disparity gap will require community-level interventions, said Gehlert, who adds behavioral therapies that would help some of the most vulnerable women in her study better cope with stress are insufficient and more or less impractical.

“Asking them to cope is just cruel,” she said, positing that very vulnerable people, with whom social workers are likely to work, have little or no control over the stressors in their environment that are implicated in exacerbating disease.

The NASW Foundation’s Social Work Policy Institute promoted Gehlert’s NIH lecture in the social work community and, following her lecture, hosted a reception for Gehlert.