A national drug shortage is threatening to disrupt cancer therapy for 24-year-old Tammie Miura and at least 100 Hawaii patients who use the medicine as a main source of treatment.

Hospital officials nationwide are fearful that the drug, methotrexate — a crucial medicine in the treatment of childhood cancers — will be exhausted within the next two weeks after a major supplier stopped producing it in November. Hawaii has not yet seen a shortage because local hospitals typically stock up on the drug, though medical providers and patients are worried that could soon change.

"It is quite scary to think that they won’t have the drug that we need," said Miura, who has used the medicine since she was first diagnosed with leukemia at age 12 and continues to use it for the treatment of bone cancer.

"Methotrexate is one of my main chemotherapies. For leukemia patients, they get methotrexate much more than I do. That would definitely put some kind of stop on their treatment," Miura said Friday from Kapiolani Medical Center for Women & Children, where she is being treated.

A local shortage could jeopardize the cure rate of cancer among children, said Darryl Glaser, a pediatric oncologist at Kapiolani.

"A true shortage could really be devastating to the cure rates we have for cancers," he said. "In overall pediatric cancers, 80 percent of children with cancer will be cured with cancer treatment. Methotrexate is used in many different kinds of cancers, so a shortage of methotrexate could substantially decrease the cure rate in childhood cancer."

At any given time, there are about 50 children using the drug to treat various types of cancers, including the most common, acute lymphoblastic leukemia, which most often afflicts people between the ages of 2 and 5, said Bob Wilkinson, professor of pediatrics at the University of Hawaii John A. Burns School of Medicine. Another 50 adults use the medicine to treat breast cancers or brain and central nervous system lymphomas and sarcomas, said William Loui, chief of oncology at the Queen’s Medical Center.

"It is one of the mainstays of their treatments. It’s absolutely important and essential in the therapy of many childhood cancers," Wilkinson said. Without it, "their disease would reoccur and we would have less survival."

Cancer is the second-leading cause of death among Hawaii children between 1 and 14 years old, according to the state Department of Health. Leukemia accounts for 35 percent of all cancer in local residents under age 15.

"The drug shortages are creating a critical medical situation for people with cancer who have very few other choices," Loui said.

Federal officials and national cancer doctors are concerned that the shortage will leave hundreds — and perhaps thousands — of children at risk of dying from a largely curable disease.

"This is dire," said Vale­rie Jensen, associate director of the Food and Drug Administration’s drug shortages program. "Supplies are just not meeting demand."

Acute lymphoblastic leukemia is an unusually virulent cancer of white blood cells that are overproduced in bone marrow and invade other parts of the body.

The cancer commonly spreads to the lining of the spine and brain, and oncologists prevent this by injecting large quantities of preservative-free methotrexate directly into the spinal fluid. The preservative can cause paralysis when injected into the spinal column, so cannot be used for this disease. Methotrexate is also used to treat rheumatoid arthritis.

Ben Venue Laboratories was one of the nation’s largest suppliers of injectable preservative-free methotrexate, but the company voluntarily suspended operations at its plant in Bedford, Ohio, in November because of "significant manufacturing and quality concerns," the company announced.

Since then, supplies of methotrexate have dwindled to the point where oncologists now say they fear that shortfalls might occur at many hospitals within two weeks.

"This is a crisis that I hope the FDA’s hard work can help to avert," said Dr. Michael Link, president of the American Society of Clinical Oncology. "We have worked very hard to take what was an incurable disease and make it curable for 90 percent of the cases. But if we can’t get this drug anymore, that sets us back decades."

There are four other methotrexate manufacturers in the United States, and they are trying to increase production, Jensen said. The FDA is also seeking a foreign supplier to provide emergency imports until the approved domestic suppliers can meet demand, she said.

So far this year, at least 180 drugs that are crucial for treating childhood leukemia, breast and colon cancer, infections and other diseases have been declared in short supply — a record number. Prices for some have risen as much as eightyfold. President Barack Obama issued an executive order in October to help ease the problems.

"People are panicking" about the methotrexate shortage, said Erin Fox, manager of the drug information service at the University of Utah.

Star-Advertiser reporter Kristen Consillio and reporter Gardiner Harris contributed to this report.