High-Risk Prostate Cancer Detection More Likely With Targeted MRI/Ultrasound Fusion Technique Than With Standard Biopsy
Targeted biopsy using new fusion technology that combines magnetic resonance imaging (MRI) with ultrasound is more effective than standard biopsy in detecting high-risk prostate cancer, according to a study by Siddiqui et al published in JAMA. More than 1,000 men participated in the research at the National Institutes of Health (NIH) over a 7-year period.
Targeted Fusion-Guided Biopsy vs Standard Biopsy
Researchers found that 30% more high-risk prostate cancers were diagnosed with targeted fusion–guided biopsy than with standard biopsy. In addition, 17% fewer low-risk cancers were diagnosed with the new approach, compared to the older method. In a targeted biopsy, MRIs of the suspected cancer are fused with real-time ultrasound images, creating a map of the prostate that enables doctors to pinpoint and test suspicious areas. In a standard biopsy, doctors use ultrasound guidance to take multiple random tissue samples from throughout the gland. Unlike other cancers, such as breast cancer, which can be detected through mammograms, prostate cancer is not generally diagnosed using advanced imaging.
“This study demonstrates that targeted fusion-guided biopsy could significantly enhance our ability to identify patients with high-risk prostate cancers that need more aggressive treatment,” said lead author Mohummad Minhaj Siddiqui, MD, Assistant Professor of Surgery at the University of Maryland School of Medicine and Director of Urologic Robotic Surgery at the University of Maryland Marlene and Stewart Greenebaum Cancer Center.
“With fusion technology, we now have a tool to help us differentiate high-risk cancers from low-risk ones that may require minimal or no treatment,” Dr. Siddiqui said. “There is a concern that we overdiagnose and overtreat low-risk cancers that are unlikely to be terminal. This technology enables us to make a more reliable diagnosis than the current standard practice.”
He added, “However, while these findings could translate into substantial benefit to patients, this study is preliminary with regard to clinical endpoints such as recurrence of disease and prostate cancer-specific mortality.” Dr. Siddiqui said randomized clinical trials will be needed to determine the impact of targeted biopsy on clinical outcomes.
Study Details
The study of 1,003 men was conducted at the NIH from 2007 to 2014, with Peter A. Pinto, MD, Head of the Prostate Cancer Section of the Urologic Oncology Branch, serving as the senior investigator. The participants were referred for biopsy because of elevated PSA or an abnormal digital rectal exam. They received targeted and concurrent standard biopsies.
Researchers noted that 461 prostate cancer cases were diagnosed with targeted biopsy vs 469 cases with standard biopsy. Targeted and standard biopsies produced the same results in 69% of the cases. But the scientists found that 30% more high-risk cancers were diagnosed through targeted biopsy than standard biopsy (173 vs 122 cases), and 17% fewer low-risk cancers, which are often overdiagnosed and overtreated (213 vs 258). Adding standard biopsy to targeted biopsy led to a 22% increase in cancer diagnoses, the vast majority of them for low-risk cancers.
Researchers also found that targeted biopsy was better able to predict whether the disease was low or intermediate- risk than standard biopsy or the two approaches combined. They were able to make that determination by comparing biopsied tissue with tissue taken from a patient’s prostate after it was later surgically removed.
Next Steps
E. Albert Reece, MD, PhD, MBA, Vice President for Medical Affairs at the University of Maryland, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean of the University of Maryland School of Medicine, said, “This study demonstrates that the MRI/ultrasound fusion biopsy technique offers benefits when compared to the current standard of care to diagnose clinically significant prostate cancer. Although further research is needed, this method holds promise, especially for diagnosing men with high-grade, aggressive cancers that may go undetected. Dr. Siddiqui is actively pursuing new research initiatives to bring fusion-guided biopsy into the clinical setting.”
Dr. Siddiqui plans to use MRI/ultrasound fusion in a clinical trial to identify and biopsy questionable areas within the prostate. In cases where treatment can be deferred, he will use this technology to perform more reliable active surveillance of prostate cancer requiring fewer biopsies. If the disease requires treatment and isn’t widespread, he will use focal brachytherapy to irradiate only the tumor, sparing the surrounding tissue. For patients with early-stage cancer, this option avoids many of the side effects associated with removing the prostate or irradiating the entire gland. In more severe cases, the MRI can help guide more aggressive options such as robotic surgery.
Dr. Pinto is the corresponding author for the JAMA article.
This study was funded by the Intramural Research Program of the National Institutes of Health (NIH), the National Cancer Institute, the Center for Cancer Research, and the Center for Interventional Oncology.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
