Miljenko, could I have your opinion on this:
Following my comments is an article, in which it is stated that radiation of tumors causes the tumors to increase their production of VEGF to create new blood vessels to survive.
Is it too simple of a hypothesis to think that this is a cure for cancer? Not necessarily the drug being discussed in the article, but the combination of radiation and a drug (who's drug I don't know, you're opinion here would also be most helpful) that disables the cancer's defense mechanism, that of producing VEGF?
Surely the fact that VEGF is more abundant after radiation treatment is significant. In my opinion, radiation is a highly effective method of killing cancers, but the problem is the spreading of the cancer throughout the body upon irradiation of the primary target. The goal then would be to identify the mechanism that enables this survival trait, and disable it.
I am aware that this problem is also common with surgery. The scenario there is that without the cancer there is no organism responsible for producing anti-angiogenesis compounds, as described in the previous post by me to this board. And the angiogenesis compounds currently in the body produced by the previously existent cancer are then free to start growing again.
If so, that radiation does in fact worsen the disease by stimulating VEGF production, and that VEGF is a critical compound required by the cancer to survive (as is my view since it is being produced by the tumor itself, something that it would not waste it's time doing while under attack), then what should or could be done to fix this problem right now? Surely radiation treatments will not be halted. And surely some new drug will not be mandated to be applied in a complementary treatment. One last question, if this is true, and I just found out about it, so doctor's must have known for some time, would there be any liability incursions?
And does this have anything to do with the well known fact that a person who receives an over-exposure of X Rays will develop a decrease in white blood cells and an increase in the susceptibility to infections?
Thank you very much, you are a big help to us all.
Thursday July 15 1:26 AM ET
Blocking Blood Vessels Helps Radiotherapy -Study
WASHINGTON (Reuters) - Experimental new drugs that literally starve out tumors can give a big boost to standard radiotherapy, researchers reported Wednesday.
The report adds to growing hope that such drugs, known as angiogenesis inhibitors, can boost the cocktail of approaches now used to treat cancer.
Dr. Ralph Weichselbaum and colleagues at the University of Chicago and Harvard University had already used angiostatin and endostatin, two natural body proteins being developed as drugs by Maryland-based Entremed Inc. (Nasdaq:ENMD - news), to boost radiotherapy.
Writing in the journal Cancer Research, they said they tried a third drug that attacks angiogenesis, called anti-VEGF.
''Despite all the media attention devoted to angiostatin and similar agents, most scientists suspect it's unlikely that, by themselves, these new drugs will have a very dramatic effect on most types of cancer,'' Weichselbaum said in a statement.
''But we have long been certain that radiation therapy works quite well for eradicating relatively small human tumors,'' he added. ''Now we have good reasons to believe that combining radiation with angiogenesis inhibitors can make this well-established treatment significantly more effective, perhaps even against comparatively large tumors, with very little added toxicity.''
Several drugs that affect the growth of blood vessels, a process known as angiogenesis, are being tested against cancer. Many attack one of the compounds that starts this growth, known as vascular endothelial growth factor (VEGF).
Weichselbaum's team found that tumors produce three to six times more VEGF after they are exposed to radiation. The higher levels last for up to two weeks.
It seems the tumors are sprouting new blood vessels to help them recover from the damage done by the radiation therapy.
Working in mice, they compared the results of using an anti-VEGF compound, radiation alone, or anti-VEGF plus radiation.
The combination worked better than either approach alone in four kinds of tumors -- Lewis lung carcinoma, human squamous cell carcinoma, human esophageal adenocarcinoma and a glioblastoma, which is a kind of brain tumor.
''The antitumor effects were greater than additive,'' the researchers wrote.
Even a little anti-VEGF greatly boosted the effects of radiation, they said.
''The combination of anti-VEGF and radiation therapy was much more effective than we might have expected,'' Weichselbaum said.
The researchers used an antibody made by R&D Systems of Minneapolis, Minnesota. Several biotechnology companies have drugs or antibodies in the clinical pipeline that work against VEGF, including Genentech, Agouron WLA.N., ImClone Systems Inc. and Sugen Inc. (Nasdaq:SUGN - news)
Other anti-angiogenesis drugs being developed attack angiogenesis in different ways. |
