Renee Mosier was one of an estimated half-million patients in the United States who were unable to get the drugs they needed because of shortages.

"You feel like you're in a fight with one hand tied behind your back," said Mosier, 56.

It was a fight she lost in June.

According to the Food and Drug Administration, the number of drug shortages has increased nearly 300% since 2005. More than half of the drugs on the shortage list are considered critical -- meaning they have no alternative. The drugs most often in short supply include anesthetics and oncological drugs.

Mosier was diagnosed in 2006 with ovarian cancer, the fifth-deadliest cancer for women, according to the American Cancer Society.

Surgery and treatment were able to keep her tumors at bay until 2009, when she returned to surgery. She was back in remission until June 2011, when her cancer appeared once again.

Mosier was able to get her required surgery, but her doctor, Dr. Wendel Naumann, was unable to get Doxil, the chemotherapy treatment she needed.

'A huge, growing crisis in this country'

"This is a huge, growing crisis in this country, where we're actually having to ration drugs," said Naumann, who calls it "unbelievable."

In November 2011, Mosier appeared on CNN's "Sanjay Gupta, MD" to share her ordeal. She told Dr. Sanjay Gupta, CNN's chief medical correspondent, that without Doxil, she had few alternatives.

"At the time we just said, 'Let's go with what we have, and see what happens,' and the cancer pretty rapidly recurred."

Mosier was never able to get another dose of Doxil and spent the last month of her life in hospice care. She was able to make one last trip -- to the Bahamas to attend her daughter's wedding.

In a follow-up interview with Mosier's daughters on this past weekend's "Sanjay Gupta, MD," daughter Michelle Philipp told Gupta, "We weren't sure until even (the) last minute if she was able to come. So we bought her the ticket, hoping it would give her something for her to look forward to, and she did, and it was just wonderful."

On June 29, 2012, Mosier died.

Philipp's sister, Nicole Penninger, didn't hide her frustration with the situation. "You feel like you're in this time now, it's 2012. You feel like, you're in America. Why can't she get these drugs, that she needs to treat something so serious?"

Critical dependence on a few companies

How did it get to this point?

According to Naumann, "We only have a couple of companies, and the problem is that if one of these companies goes down because of FDA inspections, manufacturing problems or something like that, we don't have those drugs if only one company is making them."

The House Oversight Committee came to the same conclusion. In a recent report, the panel claimed the FDA -- the very agency tasked with dealing with shortages -- is partly to blame for the shortage situation.

The report paints a scathing picture of a regulatory agency that gave little consideration to the potential outcome of its actions.