More men who are under the impression that they have low-risk prostate cancers are opting for active surveillance, abandoning treatment and observing the cancer closely with prostate-specific antigen (PSA) tests, digital rectal exams, and ultrasounds at regular intervals to note if their tumors are growing.
However, according to a recent UCLA study, selection of men for active surveillance should be predicated not on the widely utilized traditional biopsy, but with a new, image-guided targeted prostate biopsy. The new biopsy technique, founded by a multi-disciplinary team on the Westwood campus, is now a standard part of the UCLA active surveillance program.
UCLA researchers discovered that traditional "blind" biopsy failed to show the true degree of supposed low-risk prostate cancers, and that's when targeted biopsy was used and introduced, over a third of these men had more aggressive cancers than they first realized. Their aggressive cancers were not identified or spotted by traditional blind biopsy using ultrasound alone, and the men were referred to UCLA's active surveillance program under the impression that they were at no immediate risk.
The study appears in the May issue of the peer-reviewed Journal of Urology.
The targeted biopsy method, under study at UCLA since 2009, is conducted by joining magnetic resonance imaging (MRI) with real-time ultrasound, a method of fusion biopsy, in a device known as the Artemis. Prior work from UCLA exhibited the value of the new procedure in identifying cancers in men with rising PSA who had negative traditional biopsies. This study is the first of its kind to demonstrate the value of using it early in the selection process for men interested in active surveillance.
"These findings are important as active surveillance is a growing trend in this country. It's an excellent option for many men thought to have slow-growing cancers. But we show here that some men thought to be candidates for active surveillance based on conventional biopsies really are not good candidates," said study senior author and professor of urology and director of the UCLA Active Surveillance Program, Dr. Leonard Marks.
Marks and his colleagues spotted 113 men enrolled in the UCLA active surveillance program who met the standard for having low-risk cancers based on traditional biopsies. Study volunteers were subjected to an MRI in order to visualize the prostate and any lesions. That information was then put into the Artemis device, which combined the MRI pictures with real-time, three-dimensional ultrasound, enabling the urologist to visualize and target lesions during the biopsy.
"Prostate cancer is difficult to image because of the limited contrast between normal and malignant tissues within the prostate. With the Artemis, we have a virtual map of the suspicious areas placed directly onto the ultrasound image during the biopsy. When you can see a lesion, you've got a major advantage of knowing what's really going on in the prostate," said Marks.
"Of the 113 volunteers enrolled in the study, 41 men or 36 percent were found to have more aggressive cancer than initially suspected, meaning they were not good candidates for active surveillance. The findings should result in a re-evaluation of the criteria for active surveillance. We are hesitant now to enroll men in active surveillance until they undergo targeted biopsy. Fusion biopsy will tell us with much greater accuracy than conventional biopsy whether or not they have aggressive disease," he added.
Prostate cancer is the most commonly diagnosed cancer in men apart from skin cancer. Approximately 233,000 new cases of prostate cancer will take place in the United States in 2014. From those cases, almost 30,000 men will die.
"For men initially diagnosed with low-risk prostate cancer, MRI-ultrasound confirmatory biopsy including targeting of suspicious lesions seen on MRI results in frequent detection of tumors. These data suggest that for men enrolling in active surveillance, the criteria need be re-evaluated to account for the risk inflation seen with targeted prostate biopsy," the study states.
However, Marks notes that "for men with a negative targeted biopsy, a degree of reassurance is provided that is much greater than that offered by the older, blind biopsy method."