Detecting the Unseeable: Metastatic Prostate CancerDetecting the Unseeable: Metastatic Prostate Cancer
Arrows show prostate cancer metastases. Thanks to molecular imaging, scientists can actually see small bits of prostate cancer that have spread to other sites in the body. A recent breakthrough in molecular imaging research is a new agent, developed in the lab of Martin Pomper, M.D., Ph.D., which attaches a radioactive tag – one molecule at a time – only to prostate cells. "It targets PSMA, the prostatespecific membrane antigen, which sits on the surface of prostate cancer cells," explains Pomper, "and then this compound is visible on a PET scan." In December 2012, Pomper and colleagues published their discovery of the first small-molecule imaging agent that targets PSMA for PET imaging. That paper, published in the Journal of Nuclear Medicine, won the Editor's Choice Award as one of the journal's top three articles of the year.
"Molecular imaging can not only detect small amounts of disease for staging cancer, but also can be used to monitor how well treatment is working, and potentially to help us understand the biology of the disease in a particular patient," says Pomper. "We have a second-generation version of this compound that has recently completed toxicity studies, and we hope to move it fully to the clinic and test it against our original compound." In other work, Pomper's lab has developed a system for imaging and potentially treating prostate cancer. "It makes sense that if we can target these compounds with an imaging agent, we might also be able to target them with cancer-fighting drugs or radiation. In our preclinical studies, the imaging portion of this project has proven more sensitive than the current clinical standards." Graduate student Akrita Bhatnager, who works in Pomper's lab, recently presented this work at a joint meeting of the American Association for Cancer Research and the Society of Nuclear Medicine and Molecular Imaging.