SAN FRANCISCO—For the first time, clinicians may have an imaging tool that can help distinguish clear cell renal cell carcinoma (RCC) from other kinds of renal masses.
New data from a prospective multi-center phase 3 study presented at the American Urological Association annual meeting suggest that use of a monoclonal antibody called 1241-girentuximab with positron emission tomography (PET) and computed tomography (CT) imaging may help preoperatively diagnose clear cell renal cancer with the potential to alter treatment planning. The antibody binds to a unique protein expressed by clear cell RCC cells.
The study, which enrolled 226 patients, found that the imaging technique had a sensitivity of 86% and a specificity of 87% for clear cell RCC, with a positive predictive value of 95%.
“The ability to distinguish pre-operatively between aggressive and less aggressive kidney masses is a critical clinical challenge,” said investigator Robert G. Uzzo, MD, Professor and Chairman of Surgery at Fox Chase Cancer Center in Philadelphia. “Such information makes a direct impact on patient management, giving physicians the ability to match tumor biology to appropriate treatment strategies.”
Currently, kidney cancer is a radiographic diagnosis. Treatment decisions often are made based on the findings of a solid mass on CT or magnetic resonance images. Unfortunately, these tests cannot distinguish the different types of kidney cancers, which have variable risks. As more Americans continue to be scanned as part of their evaluation for various ailments and symptoms, the number of kidney tumors found serendipitously has increased such that now up to 70% of kidney cancers are discovered this way, according to Dr. Uzzo.
Many patients with such incidentally detected masses will be offered surgery. The tumors, however, are not infrequently found to be benign or indolent after surgery, and many patients may not have required immediate surgical intervention. In the absence of a definitive pre-surgical diagnosis, clinicians generally opt for surgery.
The results from this study, which Dr. Uzzo presented, demonstrated that the use of 1241-girentuximab with PET and CT imaging can help distinguish clear cell RCC form other types of benign or malignant masses.
If 1241-girentuximab (Redectane) obtains FDA approval, it will for the first time make possible diagnostic scans that can distinguish not only a tumor’s origin and location, but also provide data on its histology. Physicians and patients would be able to make more informed treatment choices.
“This is type of molecular imaging is a step beyond simple PET scan whereas it is a kind of disease-specific imaging,” said Dr. Uzzo, who is Medical Director for Urology at Renal & Urology News. “It is not only kidney cancer-specific, but histology-specific. Most kidney cancers are now diagnosed based solely on the presence of a solid mass in the kidney, not knowing if it is cancer and, if it is, what type of cancer it is.”