Black patients with advanced colon cancer are less likely to receive chemotherapy after surgery to excise tumors than white patients, a U.S. study suggests.

The treatment disparity seen in recent years may be tied to the economic downturn following the 2008 financial crisis, said lead study author Caitlin Murphy, an epidemiology researcher at the University of North Carolina at Chapel Hill.

“Black Americans were disproportionately affected by the recession, and, combined with the escalating cost of chemotherapy drugs, this may have contributed to a lower receipt of chemotherapy,” she said by email.

Murphy and her colleagues analyzed data on patients with what’s known as stage III colon cancer, when the diseased tissue may have grown into the outermost layer of the colon wall and some surrounding lymph nodes without spreading to other organs. Surgery followed by chemotherapy is recommended to treat the existing tumor and help prevent cancer from returning.

They randomly selected patients from the National Cancer Institute’s registries, pulling data from the years 1990, 1991, 1995, 2000, 2005 and 2010.

The researchers reviewed medical records for 835 white and 384 black patients, and verified the information with physicians who originally treated them.

Overall, roughly two thirds of patients received chemotherapy after surgery during the study period, the researchers report in the Journal of Clinical Oncology.

Among the kind of patients who are ideal candidates for this treatment protocol – people under age 75 with few other health complications – 87 percent of whites and 67 percent of blacks received it in 2010.

The type of insurance patients had, whether private benefits through an employer or public coverage through Medicare or Medicaid, was not associated with whether they received chemotherapy.

For people diagnosed in 2005 and 2010 who did receive chemotherapy, white and black patients got similar drugs, the study found.

Following large disparities in the early 1990s, between 1995 and 2005, the proportion of blacks and whites receiving chemotherapy tracked pretty closely. The proportions peaked, and were nearly identical, in 2005, when 72 percent of whites and 71 percent of blacks got chemotherapy.

Compared to 2005, chemotherapy decreased among all patients diagnosed in 2010, but the decline was more pronounced among blacks. That year, 66 percent of whites and 57 percent of blacks, overall, received the treatment.

Cost may be one factor influencing who receives chemotherapy, with newer treatments running in excess of $25,000 compared with a few hundred dollars at most for older regimens.

“It is important for providers and patients to include costs of cancer care in their discussions of treatment options,” Murphy said. “This is especially critical as the types of chemotherapy drugs – and their costs – continue to change.”

It’s not clear from the study whether physicians recommended chemotherapy less often to blacks or whether blacks opted against this treatment, noted Dr. Veena Shankaran, an oncology specialist at the University of Washington School of Medicine and Fred Hutchinson Cancer Research Center.

It’s possible that racial disparities in treatment might be less about out-of-pocket insurance costs or co-payments and more tied to other factors such as access to transportation, the ability to miss work for chemotherapy or the availability of childcare, Shankaran, who wasn’t involved in the study, said by email.

“If co-payments really drive the disparity, one would expect to see some difference in chemotherapy receipt by insurance plan,” Shankaran said. “Health care systems should also be sure to provide education, support and financial counseling to individuals of all races.”