Are MRI-ultrasound guided biopsies effective during active surveillance?

This study examined the effectiveness of biopsies guided by imaging techniques in detecting prostate cancer upgrades during active surveillance. Researchers advised that clinicians may consider using both systematic (conventional) and imaging guided biopsies during active surveillance.

Some men with low- or intermediate-risk prostate cancer may benefit from delaying treatment. Active surveillance refers to actively monitoring tumor growth without actually administering treatment. Active surveillance involves regular biopsies (tissue samples) to be taken from the prostate gland. If cancer cells are found to be aggressive (high Gleason score), prostate cancer may be upgraded and treatment initiated.

Biopsies are typically done blindly, by systematically taking a number of separate tissue samples from different locations on the prostate gland. Biopsies can also be guided by imaging techniques (scans that provide a visual representation of the interior of the body). A combination of magnetic resonance imaging (MRI) and ultrasound is effective in guiding biopsies at diagnosis. However, its value as part of active surveillance is still being investigated.

The aim of this study was to examine the effectiveness of MRI-ultrasound guided biopsies during active surveillance.

207 men undergoing active surveillance of prostate cancer were included in this study. 67% of men had a Gleason score of 6 at diagnosis. All men underwent both a systematic biopsy and an MRI-ultrasound guided biopsy. The average time since the last biopsy was 15.7 months. The rates of upgrading from the last biopsy were examined between biopsy techniques.

24% of systemic biopsies resulted in upgrading of Gleason score. 14% of MRI-ultrasound guided biopsies resulted in upgrading of Gleason score. MRI-ultrasound guided biopsy alone missed 39 patients in need of upgrading to a Gleason score of 7 or higher. However, it detected an upgrade in an additional 34 cancers not seen by the systematic biopsy.

Older age was found to significantly increase the likelihood of upgrading in men with a Gleason score of 6 or less at the last biopsy. This analysis accounted for prostate size, blood markers, and time since last biopsy.

Researchers concluded that MRI-ultrasound guided biopsies increased the detection rate of upgrading in some men. However, some tumors were missed by the MRI-ultrasound guided biopsy alone. Researchers advised that clinicians may consider using both systematic and MRI-ultrasound guided biopsies during active surveillance.