African American lung cancer patients who live in segregated, low-income neighborhoods are less likely than their peers in more affluent communities to get surgery that can add years to their lives, a U.S. study suggests.
Compared to black patients living in the least segregated areas, residents of the most segregated communities were at least 60 percent less likely to receive surgery for non-small cell lung cancer, the most common form.
A greater proportion of black patients died during the study, and African Americans typically had fewer months of survival after their diagnosis than whites, the study also found.
"Our survival analysis showed black patients who lived in areas with both high levels of poverty and segregation had lower survival rates, even after we controlled for the effect of receiving surgery," said lead study author Asal Mohamadi Johnson, a researcher at Stetson University in DeLand, Florida.
"We found it surprising that area level poverty by itself did not explain differences in survival among black patients, rather its effect was seen only when combined with segregation," Johnson added by email.
To assess disparities in lung cancer treatment and outcomes, Johnson and colleagues examined data on nearly 8,300 patients in a Georgia cancer registry from 2000 to 2009. They followed patients until death or January 1, 2012.
Overall, black patients had 43 percent lower odds of receiving surgery than white patients. But this gap disappeared after adjusting for the combination of race, neighborhood level poverty and segregation, the researchers report in the journal Cancer Epidemiology, Biomarkers and Prevention, online May 2.
They used census records to rank patients' neighborhoods into four groups based on income levels and the degree of segregation.
For black patients, neighborhood segregation was the strongest predictor of whether they would receive surgery. Compared with those in the least segregated areas, patients in the most segregated areas were 65 percent less likely to receive surgery.
By contrast, education levels in the neighborhood were the biggest predictor of surgery for white patients. Whites in the least educated areas were 48 percent less likely to get surgery than their peers in the most educated communities.
Black patients also had lower five-year survival than white patients, but this gap disappeared after controlling for whether people received surgery. This suggests that the disparity in survival may be explained by differences in receipt of surgery, the authors conclude.
Limitations of the study include the lack of data on individual patients' social or economic status, medical conditions or insurance, the authors note. They also lacked data on the cause of death, meaning some people might have died of causes unrelated to lung cancer.
Even so, the study adds to a growing body of research exploring the root causes of racial disparities in health care, said Caitlin Murphy, an epidemiologist at the University of North Carolina at Chapel Hill who wasn't involved in the study.
"Racial disparities in cancer treatment and outcomes are complex," Murphy said by email.
"The poor outcomes we frequently observe in black patients are likely due to a variety of patient-, provider- and system-level factors," Murphy added. "This study adds to our knowledge of how the larger neighborhood context may also influence the receipt of quality cancer care."