Fayetteville, N.C. — Collin Henry, 5, has been battling cancer since he was 2 years old. Now, the medication he takes to treat his leukemia is in short supply.

The Fayetteville boy is among more than 500,000 patients affected by the shortage of 28 cancer drugs. The issue is due, in part, to a smaller profit margin, because many of the medications have become generic. With fewer suppliers, the largest manufacturer of methotrexate, the drug Collin takes, shut down its plant last fall.

"I almost feel like throwing up. I actually felt sick to my stomach. It's a scary feeling knowing that one of the drugs that is necessary to treat your kid might not be available in the near future," Collin's mother, Kathleen Henry, said Tuesday. "It's actually really disturbing to me that they would put money after lives – that it comes down to that."

Henry said that without methotrexate, her son's treatment could be set back decades. 

After going into remission, Collin's cancer returned last August. He goes to the Lineberger Comprehensive Cancer Center at UNC Hospitals in Chapel Hill for treatments weekly.

"Twenty or 30 years ago, kids didn't survive leukemia. They were sent home to die," Henry said.

A Lineberger center spokeswoman said the system is doing everything it can to ensure an adequate supply of the medication. 

Sometimes treatment options involve less potent alternatives, or sharing with other hospitals in the region.

"It's not dire straits for us, but it is for other kids that didn't get it yesterday or aren't getting it today," Henry said.

The Henry family has battled cancer before. In October 2010, cancer also struck Collin's older brother, Patrick, now 7. It was hepatoblastoma, a rare childhood cancer that originates in the liver. He has been cancer-free for a year.