By Nancy Weil, IDG News Service
April 15, 2004 | One day, patients will be treated with low-toxicity drugs for cancer years before tumors show up, according to angiogenesis advocate Judah Folkman.
The advent of anti-angiogenesis drugs, blocking the growth of new blood vessels that feed cancer cells, raises a tantalizing question, Folkman said: “Could you begin to think of treating cancer very, very early – before it ever shows up? We know it takes seven to 10 years after the angiogenesis switch kicks in (for cancer to become evident), so why not treat it early?” Such a shift in cancer treatment requires biomarkers that would reveal which patients are going to develop cancer, said Folkman, director of surgical research at Children’s Hospital in Boston and a professor at Harvard Medical School, speaking at a Massachusetts Biotechnology Council forum.
Despite promising research to identify such biomarkers, the response from Folkman’s colleagues to his question has typically been, “you’ve gone crazy.” But his colleagues know better than to doubt Folkman’s vision. “Scientists such as myself find it difficult to change their beliefs,” he said, using as an example a paper his team published in 1971 on angiogenesis in tumor formation. It took eight years and multiple rejections before the report finally appeared.
Today, there are dozens of papers published weekly about angiogenesis, and research has shown that tumors “use proteins to recruit blood vessels” that then surround and feed the tumors. Drug companies are developing angiogenesis inhibitors, such as Genentech’s Avastin, which last month became the first-ever angiogenesis inhibitor approved by the FDA.
Many angiogenesis inhibitors are produced naturally in the body, and there is mounting evidence that they keep cancers at bay. Autopsies performed on people who have died because of traumas such as auto accidents indicate that many have “microscopic colonies of cancer cells, also known as in situ tumors,” Folkman and Raghu Kalluri of Beth Israel Deaconess Medical Center recently wrote in Nature. The body’s angiogenesis defense could be what keeps tumors from becoming malignant.
Studies involving people with Down syndrome could be important in establishing such links, he said in his talk. Down syndrome patients rarely develop cancer. They do, however, have elevated levels of the angiogenesis inhibitor endostatin because of the extra copy of chromosome 21, Folkman said.
Folkman suggested that resistance to his style of research comes from long-held beliefs about how cancer develops and how it should be treated. But he clearly believes that a time of “cancer without disease” could be in the offing.