Researchers treated cancer in mice by cutting off the blood flow to the tumors with anti-angiogenesis compounds RELATED VIDEO CNN's Dan Rutz looks at this expanding area of cancer research Windows Media 28K 80K

May 7, 1999
Web posted at: 9:27 p.m. EDT (0127 GMT)

From Medical Correspondent Dan Rutz

BOSTON (CNN) -- It's been a year since researchers generated excitement by announcing a novel way of treating cancer -- by cutting off the flow of blood to tumors in mice.

But a year later, Dr. Judah Folkman and his work remain bound to the lab and out of the limelight.

Human trials of his anti-angiogenesis compounds -- endostatin and angiostatin -- are due to begin later this year. It was the combination of those two drugs that reportedly cured cancer in mice.

Angiogenesis is the formation of blood vessels. The anti-angiogenesis compounds can block development of microscopic blood vessels and cut off the tumor's lifeline.

The hope is that by preventing angiogenesis, cancerous tumors will lose their ability to grow and spread.

At the Angiogenesis Foundation in Boston, telephone operators have been busy linking doctors and patients to this expanding area of cancer research.

"Patients are asking about angiogenesis, doctors are learning about angiogenesis, biotechnology companies are developing medicines based on angiogenesis and Wall Street is fueling the development of this new approach in medicine," said Dr. William Li of the Angiogenesis Foundation.

Thalidomide tested on cancer patients

While the two drugs from Folkman's lab have yet to make it to patients' bedsides, nearly two dozen anti-angiogenic drugs are being tried in people with cancer.

One of those drugs is thalidomide, a drug best known for causing tragic birth defects 40 years ago when doctors in some countries prescribed if for nausea in early pregnancy. The drug may have interrupted essential blood vessel growth in the womb, which affected the growth of limbs in the developing babies.

Today, under stringent safeguards to prevent pregnancy, the anti-angiogenic effects of thalidomide are being tested against brain tumors. Early results show it may keep some tumors from growing larger.

"I think the thalidomide experience in advanced tumors that we've looked at has given us some proof of principle," said Dr. Howard Fine of the Dana-Farber Cancer Institute.

Fine expects that thalidomide and other drugs like it will eventually be used in combination with standard cancer treatments or combined with other anti-angiogenic compounds.

"The other major area is to begin to look at the use of these compounds much earlier in the course of treatment of the patient with the disease," Fine said.

As with Folkman's compounds, thalidomide first proved itself in mice, where it did not cause birth defects -- an example of why scientists are wary that promising results will necessarily carry over from the cage to the clinic.