"It's hard enough to get the courage to fight the cancer and then to be thrown into despair of thinking your financial world has collapsed," Jerome said.
She was stuck paying $46,000 for treatment her insurance company wouldn't cover.
"I was aghast when I started getting the bills. And it took me a while to figure out what was going on," she said.
Here's what was going on: Insurance companies determine reimbursement for out-of-network care based of what's called "usual, customary and reasonable rates" or UCR.
Those rates are determined by a firm called Ingenix. It turns out, Ingenix is owned by United Health Group, one of America's biggest insurance providers.
On Tuesday, New York state Attorney General Andrew Cuomo called it a conflict of interest that lowballs a medical provider's average fee by as much as 28 percent.
"These companies that have been involved with Ingenix, there is a very strong case that they were perpetuating consumer frauds," Cuomo said.
In a decision with national implications, United Health agreed to pay $50 million to establish an independent rating agency and shut down Ingenix.
"We regret that conflicts of interest were inherent in these Ingenix database products," said United Health Group attorney Mitchell Zamoff.
"As for cheated consumers, will they ever get any of their money back from the insurance companies?" Pinkston asked Cuomo.
"Yes, yes," Cuomo said. "We said today is the first step. I believe consumers are entitled to hundreds of millions of dollars in reimbursement."
While Mary Jerome doesn't expect to get any money back herself, she hopes her fight will make a difference for other patients.