MRI Plus Transrectal Ultrasound-Guided Biopsy Study to Identify Aggressive vs. Nonaggressive Prostate Cancer

A phase III clinical trial has been initiated to determine whether multiparametric magnetic resonance imaging (MRI) combined with transrectal ultrasound (TRUS)-guided biopsy (called fusion technology) can effectively identify men with prostate cancer who are at risk of developing aggressive disease.

The study, called the Active Surveillance Magnetic Resonance Imaging Study Trial (ASIST), recently enrolled its first 10 patients. Researchers are aiming to enroll 275 men over the next three years who have recently been diagnosed with prostate cancer, with primary analysis planned one year after study recruitment is complete.

“The goal of this study is to provide new and useful information to help decide which patients would benefit from aggressive treatment and which would benefit from active surveillance,” said Dr. Nicole Onetto, deputy director and chief scientific officer of the Ontario Institute for Cancer Research (OICR; Toronto, Canada). “This would improve the cure rate in those who have high-risk disease while reducing the number of patients now choosing radical treatment when it is not warranted. This could improve quality of life for hundreds of thousands of men worldwide.”

Many prostate cancers are not aggressive and patients can benefit from active surveillance, an approach where a patient’s tumor is monitored over time to establish whether it is harmful or not. Currently many men choose to have surgery, chemotherapy, and/or radiation instead of active surveillance because it is not possible to effectively evaluate the prognosis of low-risk tumors. Because side effects of these treatments are frequently severe and long lasting, determining with certainty whether they are necessary provides a huge long-term benefit to patients.

The study is chaired by Dr. Laurence Klotz, professor of surgery at the University of Toronto and an associate scientist at the Sunnybrook Health Sciences Center (Toronto, Canada), and cochaired by Dr. Masoom Haider, head of abdominal MRI at the joint department of medical imaging at Princess Margaret Hospital and Mount Sinai Hospital (both in Toronto, CA, USA) and Dr. Andrew Loblaw, scientist and radiation oncologist at the Odette Cancer Center at Sunnybrook Health Sciences Center.

“A positive trial could change clinical practice and result in the widespread adoption of MRI targeted biopsies, enhanced with the TRUS fusion technology, to help prostate cancer patients worldwide,” said Dr. Klotz. “The MRI fusion technology could identify those patients needing immediate therapy. This would reduce cancer mortality for patients with more aggressive disease and provide significant reassurance and increase the appeal of active surveillance for subjects with less aggressive forms.”

“The current biopsy process is blind, involving 12 or more random needle samples,” said Dr. Haider. “We need a ‘manogram’ to help detect and direct a needle to any potential hidden aggressive cancer. If this trial is positive, MRI will save lives and reduce morbidity by enabling better detection of occult aggressive disease with far fewer biopsies.”

Active surveillance is increasingly recognized as being crucially important to reducing the overtreatment of nonaggressive disease while retaining the option of definitive therapy for those patients reclassified over time as higher risk. There are about 150,000 new patients diagnosed in North America each year who are candidates for active surveillance and this number is expected to increase dramatically over the next 20 years.

OICR is providing USD 2.8 million in funding over five years for the study.

Related Links:
Ontario Institute for Cancer Research
Sunnybrook Health Sciences Center