Targeted + Systematic Biopsy new “gold standard” for detection of prostate cancer - but not enough gold to afford it

Prostate Cancer Detection & MRI Prostate Cancer Screening

24 Core Systematic (random) Biopsy missed 1 in 5 Gleason >6 cancers. Combined with targeted reduced misses to 1 in 8.

A new “gold standard” for detection of prostate cancer? | THE "NEW" PROSTATE CANCER INFOLINK
A combination of systematic and targeted biopsy methods may well be the ideal that we seek to establish for the detection of prostate cancer. Making such methodology available to every patient will require patience and greater thought about who actually needs this type of biopsy. It would, for example, become more practical if we could cut down the number of men who are being given unnecessary biopsies every year.

Study compared effectiveness of 4 targeted vs. 24 systematic core biopsy

Comparative Analysis of Transperineal Template Saturation Prostate Biopsy Versus Magnetic Resonance Imaging Targeted Biopsy with Magnetic Resonance Imaging-Ultrasound Fusion Guidance - The Journal of Urology

Results

Overall 150 cancers and 86 Gleason score 7 or greater cancers were diagnosed. Systematic, transperineal biopsy missed 18 Gleason score 7 or greater tumors (20.9%) while targeted biopsy did not detect 11 (12.8%). Targeted biopsy of PI-RADS 2—5 alone overlooked 43.8% of Gleason score 6 tumors. McNemar’s tests for detection of Gleason score 7 or greater cancers in both modalities were not statistically significant but showed a trend of superiority for targeted primary biopsies (p=0.08). Sampling efficiency was in favor of magnetic resonance imaging targeted prostate biopsy with 46.0% of targeted biopsy vs 7.5% of systematic, transperineal biopsy cores detecting Gleason score 7 or greater cancers. To diagnose 1 Gleason score 7 or greater cancer, 3.4 targeted and 7.4 systematic biopsies were needed. Limiting biopsy to men with PI-RADS 3–5 would have missed 17 Gleason score 7 or greater tumors (19.8%), demonstrating limited magnetic resonance imaging sensitivity. PI-RADS scores, digital rectal examination findings and prostate specific antigen greater than 20 ng/ml were predictors of Gleason score 7 or greater disease.

Conclusions

Compared to systematic, transperineal biopsy as a reference test, magnetic resonance imaging targeted biopsy alone detected as many Gleason score 7 or greater tumors while simultaneously mitigating the detection of lower grade disease. The gold standard for cancer detection in primary biopsy is a combination of systematic and targeted cores.