More Accurate PET Imaging Biomarker Developed for Detecting Prostate Cancer

Positron Emission Tomography (PET) imaging combined with a new experimental agent can detect 97% of prostate cancers—more than those detected by pathologists when examining prostate glands that were excised.

The findings were published online in the journal Urology. The new method is better at detecting prostate cancer than any radiographical, biopsy or blood test currently in use. The study cohort consisted of 25 men suffering from prostate cancer who opted to have their prostate glands removed in a radical prostatectomy operation. Before the operation the men underwent the new imaging test.

The researchers from the Thomas Jefferson University (Philadelphia PA, USA) compared the results of the imaging test, and the examination by the pathologists. The imaging test uses a new biomarker, 64Cu-TP3805, and is administered to patients intravenously before they undergo a PET/CT (Computed Tomography) scan. The biomarker attaches itself to VPAC1 receptors on the surface of cancer cells. In addition, a radiation emitting copper peptide, Cu-64, is hooked onto the biomarker TP3805. PET Imaging can then be used to find where in the prostate the 64Cu-TP3805 has attached itself to cancer cells. The radioactive agent Cu-64 decays rapidly and has a lower whole-body radiation risk than a CT scan.

The results of the study showed that the new test identified 97%, or 105 out of 107 cancerous lesions found by the pathologists in the excised prostate glands, and nine additional lesions that were not found in the pathologic exam. The researchers also successfully investigated the use of 64Cu-TP3805 in human breast cancer, and are investigating the use of the test in animal models of bladder and lung cancer.

Senior investigator of the study, Mathew Thakur, PhD, professor of Radiology at the Thomas Jefferson University Sidney Kimmel Medical College, said, “There is a critical need for an accurate method to detect and stage prostate cancer so that the disease can be precisely managed. We believe this method has that potential. Current tests now used are inexact because they all require an invasive biopsy and these costly biopsies—which have the potential for complications—can miss 66% of cancers. It is hard to believe that hundreds of thousands of patients in the US have been relying on biopsies to dictate their treatment, when two-thirds of these tests do not accurately reflect what is happening inside the prostate. Results of this study exceeded our goal of detecting 80% of cancers seen pathologically, and provided us with real insights into how prostate cancer can be accurately imaged. A larger study that confirms these exciting findings should be conducted.”

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