Minneapolis ? Thalidomide, a drug once banned worldwide for causing birth defects, is showing promise as a possible treatment for ovarian cancer.

Scientists at the University of Minnesota found that the drug slowed down progression of the disease in women with recurrent ovarian cancer.

It’s not a cure, said Dr. Levi Downs, a women’s cancer specialist who led the study, which appears in the latest issue of the journal Cancer. But he said it may lead to better treatments and “provide more hope to women diagnosed with the cancer.” Ovarian cancer strikes about 25,000 women a year in the United States.

The study is the latest piece of evidence that thalidomide may be a powerful weapon against more than one type of cancer. The drug is used to treat multiple myeloma, a type of blood cancer, and is being tested on many other forms, including pancreatic, lung and prostate cancers.

In the 1950s, thalidomide was widely sold in Europe and Canada as a supposedly harmless treatment for morning sickness. But by 1961, it was linked to severe and disfiguring birth defects, and withdrawn from the market. It’s estimated that more than 10,000 infants were affected, including many born with missing limbs or flap-like arms after their mothers took a few teaspoons of the drug early in their pregnancies. The United States was largely saved from the epidemic because the Food and Drug Administration refused to approve thalidomide without more evidence of its safety.

But the drug started making a comeback in the 1990s, when it was approved as a treatment for a complication of leprosy.

Since then, the very thing that made it dangerous to fetuses has also made it appealing to cancer researchers, according to Downs, an assistant professor at the University of Minnesota Cancer Center.

Scientists discovered that thalidomide interfered with the development of blood vessels. So they began testing it to see if it could cut off the blood flow to cancerous tumors. They also discovered that thalidomide helps boost the immune system to fight cancer cells, said Downs.

Because of the known risks of birth defects, the government imposes strict rules whenever thalidomide is used, Downs noted. He had to undergo special training to prescribe it. Every patient has to watch a video about the dangers and sign assurances that they were informed of the risks. The drug label warns of “severe, life-threatening human birth defects.”

In the latest study, Downs and his colleagues gave thalidomide and a standard chemotherapy drug to one group of 30 ovarian cancer patients, and only the standard drug to a second group of 39 women.

The results were encouraging: 47 percent of the thalidomide group responded to treatment, meaning their tumors shrank or disappeared, compared with 21 percent in the control group. The drug also slowed recurrences of tumors.

But he cautioned that the study did not prove a difference in overall survival rate and that more testing is needed.

“This was a small preliminary study to determine if there’s something worth studying,” he said. “The answer was yes, definitely, because we saw a huge difference in the overall response rate.”

Downs said he plans to begin a new study on a chemical cousin of thalidomide, which early studies suggest may be more effective.