The national meeting of the American Chemical Society, the world's largest scientific society, will be held in Dallas, March 29 - April 2. The following paper is among the 4,700 presentations that will be made:
DALLAS, March 29 -- Researchers are a step closer to predicting how well antiestrogen therapies, such as Tamoxifen, will treat cancer in individual patients thanks to new radiotracer chemicals developed at Washington University Medical School in St. Louis. Chemist Michael J. Welch, Ph.D., presented his findings here today at a national meeting the the American Chemical society, the world's largest scientific society.
"Our data suggest that we can now tell an oncologist whether antiestrogen therapy will work for a particular person before that person begins treatment," said Welch.
His work uses the technique of positron emission tomography (PET), which relies on short-lived, radioactive chemicals that emit bursts of energy as they decay. Scientists use these chemicals to harmlessly tag substances and trace their effect in the body through PET scan images. Welch and his colleagues tagged estradiol, a natural estrogen, with the radiotracer fluorine-18 and, prior to treatment with the antiestrogen drug Tamoxifen, injected the substance into 10 patients with breast cancer. With one exception, he said, patients whose PET scans showed high uptake of the tagged estradiol by their bodies' estrogen receptors responded to the antiestrogen therapy--their tumors shrank.
Radiation is another common therapy for cancer. Radiation is less effective against tumors that are poorly oxygenated, a condition called hypoxia. Welch's group has developed copper-based radiotracers that may soon allow oncologists to assess the degree of tumor hypoxia in their patients. Using the radiotracer chemical copper-60, the researchers tagged substances that are preferentially taken up by tumor tissue. In animal studies, the copper complex became trapped in hypoxic tissue, but quickly washed out of healthy tissue. The hypoxic tumors--those that would respond well to radiation therapy--showed up strongly on a PET scan. Copper-61 and copper-64 are two other radiotracer chemicals under study by Welch's group. Each radiotracer has a different half-life, ranging from about 23 minutes in the case of copper-60 to more than 12 hours for copper-61. This makes them useful for different kinds of biomedical imaginG.
Paper ORGN 1 will be presented by M. J. Welch from 8:35 to 9:20 a.m., Sun., March 29, in the Convention Center, Ballroom A I, Level 3.
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A nonprofit organization with a membership of more than 155,000 chemists and chemical engineers as its members, the American Chemical Society publishes scientific journals, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.