Drug Helps Radiation Therapy Shrink Tumors
Anti-VEGF, a newly-developed cancer drug, may greatly enhance radiation therapy's ability to shrink tumors, according to new research.
Use of anti-VEGF and radiation therapy in combination "appeared to make existing tumor blood vessels more susceptible to radiation damage," wrote study lead author Dr. Ralph Weichselbaum of the University of Chicago. The findings were published in the journal Cancer Research.
Anti-VEGF has a similar mode of action as angiostatin and endostatin, drugs that starve tumors by preventing them from developing a blood supply. Specifically, anti-VEGF blocks the action of vascular endothelial cell growth factor (VEGF), an enzyme involved in the production of new blood vessels.
Weichselbaum cautioned that these types of agents may not, "by themselves … have a very dramatic effect on most types of cancers." Instead, his team found that the use of anti-VEGF and radiation in combination is much more effective at shrinking tumors than the use of either therapy alone.
Anti-VEGF is already being tested in clinical trials. Weichselbaum believes its use with radiation therapy "has the potential to make an established cancer therapy much more effective without more side effects."
Source: Reuters, Cancer Research
Oral vs. IV Antibiotics in Cancer Patients
Oral therapy with broad-spectrum antiobiotics appears to be an acceptable alternative to intravenous therapy in low-risk cancer patients, according to two studies published in the New England Journal of Medicine.
The studies compared oral doses of ciproflaxacin plus amoxicillin-clavulanate to intravenous doses of either ceftazidime or ceftriaxone plus amikacin.
In the first study, the researchers enrolled cancer patients who had fever and neutropenia during chemotherapy. Only those patients who had evidence of neutropenia for no more than 10 days and no other underlying conditions were accepted. The patients received either oral ciprofloxacin plus amoxicillin-clavulanate or intravenous ceftazidime.
Treatment was successful without modifications in 71 percent of the oral-therapy patients and 67 percent of the IV-therapy patients.
The second study enrolled febrile cancer patients with granulocytopenia. Treatment was successful in 86 percent of patients in the oral-therapy group and 84 percent of those in the intravenous-therapy group.
Both groups of researchers concluded that oral antibiotics are as safe and effective as intravenous therapy in hospitalized low-risk cancer patients undergoing chemotherapy.
In an editorial which appeared in the journal, Drs. Robert Finberg and James Talcott of Harvard Medical School cautioned that the results of these studies do not justify using oral therapy for outpatient treatment.
"This approach has yet to be validated in large, randomized studies designed to assess this critical question: 'Is outpatient treatment of fever and neutropenia, away from the watchful eyes and readily available emergency equipment of the hospital, as safe as inpatient treatment, or at least safe enough?'"
Source: Doctor's Guide, New England Journal of Medicine
Researchers have discovered evidence of a virus linked to human breast cancer which they say could someday lead to the development of a vaccine for the disease.
The virus, almost identical to one causing breast cancer in laboratory mice, was found in more than 85 percent of women with breast cancer, according to Robert Garry of Tulane University in a presentation to an international virology conference in Sydney, Australia.
The human mammary tumor virus, which Garry said was hereditary and non-infectious, was also discovered in 20 percent of people without breast cancer.
"If the virus has the same role in human breast cancer as in mouse breast cancer, then this is a very significant step in fighting the disease," Garry said. If so, "finding a vaccine shouldn't be all that difficult," he added.
However, a number of breast cancer specialists were skeptical, saying the link between a virus and disease was not necessarily causal.
"Fifty percent of women who have breast cancer might also have brown hair. That doesn't mean brown hair causes cancer," said John Boyages, director of the New South Wales Breast Cancer Institute. "This association is interesting, but needs to be replicated in bigger numbers," Boyages said. The U.S. study was done on 30 breast cancer patients.
Garry added that his findings could also help the early detection of breast cancer, as the hereditary virus would show up in DNA taken from a simple blood test.
Source: Reuters
New Cancer-Fighting Proteins Found
A team of researchers say they have found two new cancer-fighting proteins they think will prove especially powerful in starving cancerous tumors. The proteins will join an arsenal of drugs being developed to fight cancer in a novel way-by choking off the blood supply that cancers create to feed themselves.
Human Genome Sciences, a Maryland-based company that specializes in searching the collection of human genes for useful new proteins, has named its discoveries METH-1 and METH-2. It said they work better than the highly publicized protein endostatin.
Huge attention has surrounded the development of endostatin and similar compounds, known as angiogenesis inhibitors. Endostatin has just received permission from the Food and Drug Administration to begin testing on human volunteers.
"The use of angiogenesis inhibitors is one of our most promising cancer-fighting strategies," said Judith Gasson of the Jonsson Cancer Center at the University of California Los Angeles, where the proteins were tested.
Writing in the Journal of Biological Chemistry, molecular biologist Luisa Iruela-Arispe and a team at UCLA said METH-1 and METH-2 act by interfering with the growth of endothelial cells, which are key to blood vessel formation.
"The discovery of two novel proteins that inhibit blood vessel formation is exciting, because both proteins were shown to be more potent than endostatin or thrombospondin in preventing new blood vessel formation," she said.
Source: Reuters, Journal of Biological Chemistry
Gene Engineering Turns Normal Cell Cancerous
For the first time, scientists have created a cancerous human cell by genetically altering a normal one in the laboratory-a breakthrough that could speed the development of drugs that wipe out tumors.
Researchers know that cancer is caused by genes turned bad, and they have been trying to develop drugs that fix these flaws. But up to now, they have been fumbling in the dark. They aren't sure exactly which combinations of flaws cause the many types of cancer. Nor do they know precisely which drugs repair which faulty genes.
Now, with this latest breakthrough, they will be able to create specific genetic flaws in the lab and then try to find drugs that work. Moreover, they can use this breakthrough to work backwards and determine which flaws cause which types of cancer.
The research was led by Dr. Robert Weinberg of the Massachusetts Institute of Technology's Whitehead Institute for Biomedical Research. It was reported in the journal Nature.
Scientists have previously been able to turn normal human cells cancerous using chemicals and X-rays. But that is a scattershot approach. The scientists have no idea exactly what kind of genetic flaws might result. Weinberg's research is part of a relatively new approach to treating cancer that is more like a rifle than a shotgun.
Scientists believe that attacking the underlying genetic flaws would not only be more effective but would also spare patients the side effects caused by today's chemotherapy drugs, which assault both cancerous cells and healthy ones.
Source: Associated Press, CNN
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