Combining Biopsy Methods Boosts Prostate Ca Detection

Clinically significant cancers detected in up to 33% more men.

This article was first published on Wednesday, June 13, 2019, in MedPage Today.

By Ian Ingram, Deputy Managing Editor, MedPage Today.

Combined use of systematic and MRI-guided targeted biopsy was better able to detect clinically significant prostate cancers than either method alone, the PAIREDCAP trial found.

Among nearly 250 men with MRI-visible prostate lesions, the detection rate for these cancers reached 70.2% with both methods combined, reported Leonard S. Marks, MD, of the University of California, Los Angeles, and colleagues in JAMA Surgery.

Detection rates for clinically significant tumors (Gleason score ≥3 + 4) were 46.8% for visual or cognitive targeted biopsy, 60.1% with systematic transrectal ultrasound-guided (TRUS) sampling, and 62.1% for either cognitive or software fusion. Of the 174 clinically significant cancers detected overall, anywhere from 11.5% to 33.3% would have been missed with one type of biopsy method alone.

"Our research suggests that the different biopsy methods identify different tumors," Marks said in a statement. "Our cancer detection rate, while using different methods in tandem, surpasses that from using either method alone. In this case, one plus one equals three."

In 20.9% of men, systematic biopsy found tumors that were missed on targeted biopsy while in 9.7%, targeted biopsy found tumors that were missed on systematic biopsy.

Regardless of the method used, detection rates of Gleason score ≥3 + 4 tumors were higher among men with Prostate Imaging Reporting & Data System (PI-RADS) scores of 4 (64%) or 5 (80.2%) compared to those with a score of 3 (23%; P=0.006).

Certain factors predicted better detection rates, including increasing PSA density (low 35%, moderate 56%, high 77.8%) and prostate volume (low 77%, moderate 62.8%, high 42%).

The researchers also biopsied 48 consecutive patients without MRI-visible lesions to test the false-negative rate of multiparametric MRI for prostate cancer diagnosis. Here, systematic sampling turned up clinically significant cancers in 15% of the patients.

"Even if the MRI is negative for lesions, men at risk -- including those with elevated levels of prostate-specific antigen, a prostate nodule, or family history -- should still receive a traditional, systematic biopsy," said Marks.

Together, the results suggest a risk-assessment model that incorporates PSA density with MRI findings and other information that could be of use, the authors said. For example, 90% of men with a PI-RADS lesion score of 5 and high PSA density (>0.15 ng/mL/cm³) had clinically significant prostate cancer compared with 8% of those with a negative MRI and a low or moderate PSA density (<0.15 ng/mL/cm³).

PAIREDCAP (Prospective Assessment of Image Registration in the Diagnosis of Prostate Cancer) was a paired cohort trial that enrolled 300 consecutive men undergoing their first prostate biopsy. The study was conducted from 2015 to 2018 at a single academic institution and used investigators with extensive experience in MRI-guided biopsy (>10 years).

Of the 300 men, 248 had lesions visible on multiparametric MRI -- PI-RADS version 2 lesion of grade 3 or greater -- and subsequently underwent TRUS biopsy (12 cores), MRI-lesion visual or cognitive targeted biopsy (3 cores), and MRI-lesion software-assisted targeted biopsy (3 cores).

Detection of clinically significant prostate cancer has been improved with the introduction of multiparametric MRI in this setting, said Ahmad Shabsigh, MD, and Cheryl T. Lee, MD, both of the Ohio State University Wexner Medical Center in Columbus, in an invited commentary.

The PRECISION trial showed that MRI-guided biopsy could detect nearly 50% more clinically significant cancers than ultrasound-guided biopsy (38% vs 26%), and led to a 13% absolute reduction in detection of clinically insignificant cancers. And the PROMIS trial showed that multiparametric MRI was more sensitive and less specific than TRUS biopsy. In the two studies, 28% and 27% of patients, respectively, would have been able to avoid prostate biopsy with use of multiparametric MRI.

"Still, a critical question went unanswered by these studies: is it better to do a standard TRUS biopsy in addition to the MRI-targeted biopsy?" Shabsigh and Lee wrote, a question that PAIREDCAP was designed to address.

"A few important lessons can be learned from this study: first, relying on targeted biopsy alone is suboptimal; second, if the urologist does not have a fusion machine, cognitive biopsy is still essential," they wrote. "The results reflect the reality that multiparametric MRI is better than what clinicians have had, but there is still a way to go."

The study was supported by the University of California, the Los Angeles Clinical and Translational Science Institute, the Jean Perkins Foundation, the Kent Kresa Family Foundation, the Steven C. Gordon Family Foundation, and a grant from the National Cancer Institute.

Marks and another co-author disclosed that they co-founded Avenda Health.

Shabsigh and Lee reported no conflicts of interest.