Uninsured cancer patients are asked to pay anywhere from 2 to 43 times what Medicare would pay for chemotherapy drugs, according to a new paper. Uninsured patients who did not negotiate the billed amounts could expect to pay $6,711 for an infusion of the colorectal cancer drug oxaliplatin. However, Medicare and private health plans only pay $3,090 and $3,616 for the same drug, respectively.

Although uninsured cancer patients were asked to pay on average two times more than Medicare paid for expensive chemotherapy drugs, very high payment differences were seen for drugs that were quite inexpensive on Medicare. For example, carboplatin was estimated at $26 for one infusion with Medicare, but the estimate for uninsured patients was $1,124.

Stacie Dusetzina, an assistant professor at the University of North Carolina at Chapel Hill, and colleagues reviewed newly available Medicare data on what physicians charged for chemotherapy drugs delivered intravenously in 2012.

"Patients with Medicare and private insurance don't pay the sticker price of health care," said Dusetzina. "They pay a discounted rate. However, uninsured patients don't have the bargaining power, or they may not try to negotiate for a better price."

In addition to estimating costs for infused chemotherapy drugs, the researchers also looked at what cancer patients were asked to pay for a doctor visit. Uninsured patients were billed between $129 and $391, depending on the complexity of the visit. Medicare paid between $65 and $188 and private insurance paid $78 to $246 for the same visits.

Under the Affordable Care Act, everyone in the United States must be insured or face a tax penalty. Despite this mandate and penalties, for poor people the penalty is cheaper than insurance. The federal government claimed that insurance companies being handed new customers would subsidize the exchanges with taxes and fees but the revenue has not gone up while costs have.

"In states like North Carolina that didn't expand Medicaid, there is a large group of people who can get insurance on the federal exchange but cannot get subsidies because the law assumed they would be covered by Medicaid," said Dusetzina, who is also a member of Lineberger Comprehensive Cancer Center. This population earns at or near the federal poverty level. Without subsidies to help pay for private insurance, many are likely to remain uninsured.

These drug pricing discrepancies could become even more important depending on the outcome of the pending Supreme Court case King vs. Burwell, which challenges the legitimacy of federal health-care subsidies and could stick 8 million Americans with IRS-enforced health insurance but no subsidies to pay for it.