"Some of the shortages have gone on for a long period of time and under those circumstances, without a definite answer, we don't know how long that's going to exist and what kind of modifications we are going to make," said Howe.
Some medications in short supply offer an equivalent substitute, Link said. But in some cases insurance companies do not reimburse patients for the substituted therapies.
"Indeed it's a double whammy and sometimes patients who are unable to pay, therefore, cannot get a drug that would be a good substitute," said Link. "So this is compounding the problem for our patients for sure."
The U.S. Food and Drug Administration limits the number of doxorubicin therapy to eight rounds because of its potential harm. While the FDA can oversee imports of drugs that are in short supply, the agency cannot regulate how much a manufacturing company can make. In fact, manufacturers are not required to report shortages to the FDA.
The amount of drugs made available within a hospital is an agreement between the hospital and specific manufacturers.
"We [the FDA] are working with the manufacturers to address any quality issues, any issues that have caused these shortages as well as encouraging the other manufacturers of these products to continue making them in good supply," said Valerie Jensen, associate director of the FDA's Center for the Drug Evaluation and Research drug shortage monitoring program.
"What we hope is that firms come to us when there is a problem so we can help address it and so that we can help other manufacturers to increase production," she said.
Some doctors and hospitals are turning to a so-called grey market to get the supply they need. The equivalent of a black market, the drugs are in full supply but sell for a much higher price – a trade that may lead to the haves getting treated, and the have-nots left waiting.
"If they're buying product and selling it at a higher price, we understand that some of that is within the law," said Jensen. There's currently no federal oversight on the grey market, she said.
McKee, who has now completed four rounds of the drug, said his only options are to either stop therapy and wait for a full dose, or continue taking lower doses and monitor the progress.
"If the drug is going to constantly be a source of conflict with respect to it being available, that is very disappointing," said McKee. "We pay quite a lot in health insurance for it to be available."
His doctor Howe agreed, saying he's not sure whether taking lower doses will be an adequate treatment for McKee's tumor. But then again, Howe said he's not sure about waiting either.
"If I had to [lower the dose] consistently over the course of four to six months, then I think we really are compromising care," said Howe.