The study, published in the journal JAMA Internal Medicine, looked at the insurance status and health care costs of these survivors right before the Affordable Care Act was fully implemented.

Adult survivors of childhood cancer were denied health care coverage more often than their cancer-free siblings, paid more out-of-pocket for their health care, were more likely to borrow money due to health care costs and were more prone to skip filling necessary prescriptions due to their price, the study saw.

The analysis drew from the large, nationwide Childhood Cancer Survivor Study and relied on surveys of U.S. survivors conducted between 2011 and 2012. The results will serve as a benchmark for researchers studying the effects of the ACA’s rules on pre-existing conditions on this particularly vulnerable population, said Massachusetts General Hospital cancer survivorship researcher and lead author on the study Dr. Elyse Park. Those rules went into effect in 2014.

Before then, insurers were allowed to deny coverage to those with pre-existing conditions or charge them more for insurance premiums. Both practices were made illegal under the ACA.

The current study highlights the financial burden this particular population — childhood cancer survivors — faces in their adult lives and how their health insurance status affects that burden.

“The disparity in coverage is real and problematic,” Park said.

The study focused on health insurance, but for adult survivors of childhood cancers, many factors combine to form the constellation of health care cost burdens known as “financial toxicity,” said Fred Hutchinson Cancer Research Center biostatistician Dr. Wendy Leisenring, a co-author on the insurance study and lead statistician for the Childhood Cancer Survivor Study, or CCSS.

The issues “really are all intertwined,” Leisenring said.

Financial toxicity is a major problem for current cancer patients, previous research at Fred Hutch and other organizations has shown. But studies like this analysis from the CCSS are showing that the financial effects of cancer extend far beyond the cost of the initial treatment itself.

For the current study, the researchers collected surveys from nearly 700 childhood cancer survivors who are participants in the CCSS and were on average 31 years out from their original diagnoses. They compared them to surveys filled out by 210 siblings of childhood cancer survivors who served as a cancer-free comparison group. There wasn’t a huge difference in the number of uninsured among the two groups — slightly more than 10 percent of the survivors were uninsured as compared to slightly less than 8 percent of the siblings, which was not a statistically significant difference.

But the research team found that survivors’ insurance status did differ meaningfully in a few important ways. Survivors were more likely than the sibling group to receive coverage through Medicaid or Medicare. They were also more likely to have been denied insurance coverage: Less than 2 percent of the sibling group reported being denied health insurance in the past as compared to more than 15 percent of the cancer survivors.

The researchers then drilled down into the survivors’ expenses, their access to health care and their state of mind surrounding their health. The team compared both the survivors to the siblings as well as the insured to uninsured survivors. They found that survivors’ average annual out-of-pocket expenses were about $800 more than those of the siblings: nearly $2,400 versus nearly $1,600.

This finding is even more striking when taken in the context of other research about childhood cancer survivors, Leisenring said. The current study saw that survivors’ annual household income was on average lower than that of the control group, and past research from the CCSS found that survivors are more likely to be unemployed due to their he