Early Repeat Biopsies ‘Safely Omitted’ With Multiparametric MRI Active Surveillance

Author: By Lynda Williams, medwireNews Reporter

medwireNews: A multiparametric magnetic resonance imaging (mpMRI) protocol could reduce the number of biopsies men require during active surveillance for early-stage prostate cancer, indicate 3-year findings from the MRIAS trial.

The final analysis was presented at the 37th Annual European Association of Urology Congress in Amsterdam, the Netherlands, by Paul Doan, from the St Vincent’s Prostate Cancer Research Centre in Sydney, New South Wales, Australia.

The study recruited 172 men aged at least 40 years who had chosen active surveillance to manage their biopsy-proven prostate cancer at stage cT2 or less on digital rectal examination (DRE). The patients all had a prostate-specific antigen (PSA) level of below 10 ng/mL and International Society of Urological Pathology grade group (ISUPGG) 1 disease or favourable ISUPGG 2 disease (less than two positive cores and Gleason pattern 4 of 10% or less in any core).

At baseline, the men underwent mpMRI and saturation template biopsy, and were followed up with an annual mpMRI and DRE, as well as 6-month repeated PSA testing. All examinations were repeated at 3 years including saturation biopsy.

Paul Doan explained that the standard 1-year and 2-year repeat biopsies were omitted unless there was evidence of radiological progression, defined in the study as persistent Prostate Imaging Reporting and Data System (PI-RADS) 4/5 lesion, a new PI-RADS 3 lesion, or a pre-existing PI-RADS 3 lesion with suspicious changes on imaging, such as a “marked increased in perfusion characteristics”.

Men with PI-RADS 1–2 lesions or stable PI-RADS 3 lesions at the 1- and 2-year assessments were considered to have a negative surveillance mpMRI and did not undergo biopsy until year 3, he said.

At 3 years, 24% of men had experienced pathological progression, the researcher reported.

Serial mpMRI was 57% sensitive and 82% specific for the diagnosis of clinically significant prostate cancer, with positive and negative predictive values of 50% and 86%, respectively.

The presenter said that if mpMRI progression was the only trigger for biopsy, 73% of 148 biopsies could have been avoided, although 10% of patients would have experienced a delay in their diagnosis of clinically significant prostate cancer.

Among the 15 patients whose progression was missed by mpMRI, 73% had pT2 ISUPGG 2 or low-volume ISUPGG 3–5 disease, but just 2.3% of the 172 patients who had a false–negative mpMRI had one or more high-risk pathological features, such as any pT3 disease or ISUPGG greater than 2 with high-volume prostate cancer.

After a median 69 months of follow-up, one patient had experienced disease progression and was found to have nodal micrometastases on radical prostatectomy; this individual received adjuvant androgen deprivation therapy and radiotherapy and was free from biochemical recurrence 25 months after surgery.

Of the 172 participants, 54 patients have now received radical treatment for prostate cancer, 99% are free from biochemical recurrence, 100% from metastatic disease and there have been no prostate cancer-specific deaths, Paul Doan summarised. One patient died from pancreatic cancer.

He concluded that “1-year confirmatory biopsy may be safely omitted in [active surveillance] in which MR-targeted and saturation template biopsies are performed at baseline.”

While advising that mpMRI and PSA density can reduce the number of biopsies, he emphasized that “repeat biopsy should be performed at 3 years due to potential MRI-invisible tumours.”

Reference

• Doan PN, Scheltema MJ, Amin AA, et al. 3-year outcomes from the prospective ‘MRIAS’ trial: A novel active surveillance protocol which incorporates multiparametric MRI to reduce frequency of biopsy in men with prostate cancer. 37th Annual EAU Congress; Amsterdam, the Netherlands: 1–4 July 2022.