Novel PET imaging bests pathology in some prostate-cancer diagnostics

A preliminary study has demonstrated the feasibility of an experimental molecular biomarker to combine with PET imaging for reliably showing the extent of prostate cancer. Along the way, researchers found that the technique can also catch some cancers hidden to pathologists.

In the study, researchers at Thomas Jefferson University used a novel peptide, 64Cu-TP3805, which binds to a certain receptor found on the surface of mutating cancer cells.

The receptor is the vasoactive intestinal polypeptide receptor 1 (VPAC1).

The new biomarker was formulated by Siemens’ PetNet Solutions for clinical trials, of which the prostate study was one, by the biopharmaceutical firm NuView Life Sciences of Park City, Utah.

The research team imaged 25 patients undergoing radical prostatectomy preoperatively with 64Cu-TP3805 PET, then compared the imaging results with those from histologic findings, according to the study report, which was published online in Urology.

The new test identified 105 of 107 cancerous lesions found in pathological exams of removed glands—good for 97 percent agreement with histology.

Meanwhile, it further identified nine lesions that the pathologic exam missed.

The study’s authors contextualize their work by stating that, although their data are preliminary, the trial demonstrated that 64Cu-TP3805 can delineate prostate cancer, as well as the prostate pre-malignancy HGPIN (high-grade prostatic intraepithelial neoplasia), with excellent specificity for VPAC1.

The team concludes the report by stating that there exists a “compelling need for a biomolecule that will image prostate cancer, early and accurately, but not benign prostate conditions, and that will minimize the number of unnecessary biopsies, reduce patient anxiety and reduce healthcare cost.”

In a news release from Thomas Jefferson University, senior investigator Mathew Thakur, PhD, places the crux of the advance in the new technique’s ability to identify cancerous cells before their histologic appearance changes.

“Results of this study exceeded our goal of detecting 80 percent of cancers seen pathologically, and provided us with real insights into how prostate cancer can be accurately imaged,” he says. “A larger study that confirms these exciting findings should be conducted.”

The study report discloses that Thakur is a consultant to NuView, noting that neither the lead author nor any other co-authors have relevant financial interests in 64Cu-TP3805.