While the United States casts a worldwide dragnet for a shadowy foe, researchers at home are engaged in an ongoing struggle against possibly an even more deadly enemy: Cancer.

Cancer took 554,740 lives in this country in 1996.1 It is the leading disease-related cause of death in children under the age of 15. And cancer is costly. According to the National Cancer Institute, the bill is a staggering $107 billion (109) annually in direct health care and lost productivity.2

Clearly it is in the best interest of the economy of this country that we overcome this threat, but it will not be simple. Tumors can exist with minimal blood/oxygen flow, and cancer has proven resistant to some of our most virulent chemical cocktails and complex surgical strategies. The battle, consequently, has moved to a different front, as researchers drill down to the molecular level in their efforts to understand cancer. Imaging could play a key role in this endeavor.

“In a sense, what we call molecular imaging is already widely practiced and that has been in the purview of nuclear medicine and positron emission tomography: fundamental chemistry is imaged at a molecular level,” notes Michael W. Vannier, MD, head of the Department of Radiology, University of Iowa Medical College, Iowa City. Vannier, a member of the Institute of Medicine’s Committee on the Early Detection of Breast Cancer, cites the hybrid CT-PET and CT-SPECT scanners as well as a promising new nuclear imaging tool: trials currently are under way on SPECT imaging of a preparation of technetium Tc 99m recombinant human annexin V. Annexin V is used in the histology laboratory as a marker for apoptosis. (Essentially, it hooks onto the inside lining of a dying cell.) Patients are scanned with the agent prior to chemotherapy and then scanned a few days following the first dose of therapy. The scan provides a quantitative marker for cell death, representing a tremendous advance beyond the current method of measuring tumor size to assess chemotherapy results. “It has a good chance of being approved and having a major effect on oncology imaging,” Vannier reports.

Knowing in advance which treatments will work rather than running the course of treatment and measuring its results afterwards could result in significant reductions in unnecessary patient discomfort. Major economic benefits are implied as well.

The best way for radiology to prepare itself for battle on this new front is to encourage more radiologists to take an interest in cell biology and chemistry, no small task because there are currently only a handful. One such radiologist is David Piwnica-Worms, MD, PhD, a radiologist with a doctorate in biochemistry working at the Washington University Molecular Imaging Center at the Washington University Medical Center’s Mallinckrodt Institute of Radiology, St Louis. He and a team of chemists, biochemists, molecular biologists, nuclear medicine physicians, and oncologists have been working since 1990 on understanding the MDR-1 gene and its expression product P-glycoprotein, responsible for multidrug resistance in cancer. “It is a bench to bedside story where we have been involved in the biochemical observations, synthesis of radiopharmaceuticals, testing in animal models, and patients, and actually now have a 4-year clinical trial to test the hypothesis in patients with breast cancer,” he notes. The trial utilizes mammoscintigraphy and a radiopharmaceutical to determine if there is expression of the multidrug-resistant P-glycoprotein in a selected patient’s tumor.

Once produced, these hybrid MD-PhDs need the support and a culture conducive to research, such as that created by R. Gilbert Jost, MD, chairman of radiology at the Washington University Medical Center, and Ronald G. Evens, MD, before him. At the national level, the establishment of the National Institute of Biomedical Imaging and Bioengineering at the National Institutes of Health was an important step. War requires resources.

Cheryl Proval

[email protected]



  1. Cancer Facts & Figures-1996. Atlanta:American Cancer Society;1996.
  2. Health and the States: How Much Does Cancer Cost? National Governors Association Center for Best Practices. Available at: http://www.nga.org/center/divisions/1,1188,C_ISSUE_BRIEF^D_1915,00.html. Accessed October 2, 2001.

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