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PSMA imaging reshapes prostate cancer diagnosis, cutting biopsies in half

PSMA imaging reshapes prostate cancer diagnosis, cutting biopsies in half

New Capabilities

Australia-wide trial shows a scan that makes cancer cells glow can safely replace invasive biopsies for men with inconclusive MRI results

March 13th, 2026: PRIMARY2 trial shows PSMA PET halves biopsies safely

Overview

Every year, roughly 750,000 men in the United States alone undergo prostate biopsies that turn out to be unnecessary. On March 13, 2026, researchers at the European Association of Urology Congress in London presented results from the PRIMARY2 trial showing that a scan using a molecule that binds to prostate cancer cells and makes them glow on imaging cut the need for biopsies nearly in half, without missing dangerous cancers.

The trial matters because prostate cancer screening has been stuck in a painful tradeoff for decades: the standard blood test catches cancers early but also flags vast numbers of harmless ones, leading to biopsies that cause pain, infection risk, and anxiety, followed by treatments that can leave men incontinent or impotent for tumors that would never have hurt them. Prostate-Specific Membrane Antigen (PSMA) PET scanning now offers a way to break that tradeoff, distinguishing aggressive cancers from indolent ones before a needle ever enters the body.

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Key Indicators

49%
Biopsy reduction
Share of men in the PRIMARY2 trial who safely avoided biopsy after a negative PSMA PET scan
660
Patients enrolled
Biopsy-naive men with equivocal MRI results randomized across seven Australian centers
750K
Unnecessary biopsies per year (US)
Estimated annual unnecessary prostate biopsies in the United States under current screening practices
1.5M
Annual global diagnoses
Prostate cancer is the most commonly diagnosed cancer in men across 118 countries

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People Involved

Michael Hofman
Michael Hofman
Active researcher leading multiple PSMA imaging and therapy trials
 Louise Emmett
Louise Emmett
Active researcher and clinician in PSMA theranostics
 James Buteau
James Buteau
Presented PRIMARY2 results at EAU 2026

Organizations Involved

Peter MacCallum Cancer Centre
Peter MacCallum Cancer Centre
Cancer research hospital
Co-led PRIMARY2 trial

Australia's only public hospital solely dedicated to cancer treatment, research, and education, based in Melbourne.
European Association of Urology (EAU)
European Association of Urology (EAU)
Medical professional society
Hosted presentation of PRIMARY2 results at EAU26 Congress

The leading European professional organization for urologists, whose annual congress is one of the world's largest venues for presenting urological research.

Timeline

  1. PRIMARY2 trial shows PSMA PET halves biopsies safely

    Research

    At the European Association of Urology Congress in London, researchers present results from the PRIMARY2 trial showing that PSMA PET/CT scanning reduced the need for prostate biopsies by 49% in men with inconclusive MRI results, without missing clinically significant cancers. Diagnoses of harmless cancers fell from 32% to 14%.

  2. BIOPSTAGE trial shows PSMA PET cuts biopsy targets by two-thirds

    Research

    The BIOPSTAGE trial reports that guiding biopsies exclusively by PSMA PET-positive lesions could reduce the number of biopsy targets by approximately 66% compared with MRI alone, while maintaining 86% sensitivity and 86% specificity.

  3. FDA approves Pluvicto, first PSMA-targeted therapy

    Regulatory

    The FDA approves lutetium-177 PSMA-617 (Pluvicto) as the first radioligand therapy that uses PSMA to deliver radiation directly to prostate cancer cells, completing the "theranostic" loop from PSMA imaging to PSMA treatment.

  4. Pylarify becomes first commercial PSMA PET tracer

    Regulatory

    The FDA approves Pylarify (piflufolastat F-18), the first commercially manufactured PSMA PET tracer, expanding access beyond academic medical centers that could produce gallium-68 on-site.

  5. FDA approves first PSMA PET imaging agent

    Regulatory

    The FDA approves gallium-68 PSMA-11 as the first PSMA-targeted PET imaging agent for prostate cancer, initially for men with suspected metastasis or recurrence.

  6. proPSMA trial published in The Lancet

    Research

    The proPSMA trial, led from Peter MacCallum Cancer Centre, demonstrates that PSMA PET/CT has 92% accuracy for staging high-risk prostate cancer, compared with 65% for conventional CT and bone scans. The results are published in The Lancet.

  7. US panel partially reverses PSA screening recommendation

    Regulatory

    The task force issues an updated recommendation encouraging shared decision-making about PSA screening for men aged 55 to 69, partially walking back its 2012 blanket recommendation against screening.

  8. US panel recommends against routine PSA screening

    Regulatory

    The United States Preventive Services Task Force recommends against routine PSA-based screening for all men, citing evidence that it leads to overdiagnosis and overtreatment of indolent cancers.

  9. First patient scanned with Gallium-68 PSMA PET

    Discovery

    Researchers in Heidelberg, Germany report imaging the first patient with a gallium-68-labeled PSMA PET compound targeting the exterior of PSMA on cancer cells, producing far clearer images than earlier agents.

  10. First PSMA-based imaging agent approved

    Regulatory

    ProstaScint, using a radiolabeled antibody targeting an internal portion of PSMA, becomes the first FDA-approved PSMA imaging agent. Its accuracy proves limited.

  11. FDA approves PSA blood test for screening

    Regulatory

    The Food and Drug Administration approves the prostate-specific antigen blood test for prostate cancer screening, leading to a surge in diagnoses and the beginning of the overdiagnosis debate.

  12. PSMA gene cloned at Memorial Sloan Kettering

    Discovery

    Researchers at Memorial Sloan Kettering Cancer Center clone the PSMA gene, opening the path toward diagnostic and therapeutic applications.

  13. PSMA first identified

    Discovery

    Researchers led by George Murphy and Julius Horoszewicz develop a monoclonal antibody from mice immunized with human prostate cancer cells, identifying what would become known as Prostate-Specific Membrane Antigen.

Scenarios

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1

PSMA PET becomes standard first-line test before biopsy

As evidence accumulates from multiple randomized trials, urology guidelines incorporate PSMA PET/CT as a standard step before biopsy for men with elevated PSA but inconclusive MRI results. Insurance systems begin covering the scan for initial diagnosis, not just recurrence. The result is a measurable drop in unnecessary biopsies, infections, and overtreatment of indolent cancers across screening populations.

Discussed by: Peter MacCallum researchers and the European Association of Urology; reflected in momentum from proPSMA, BIOPSTAGE, and PRIMARY2 trials
Consensus —
2

Access barriers limit PSMA PET to wealthy countries and major hospitals

PSMA PET scanning requires specialized radioactive tracers, PET/CT scanners costing millions to install, and trained nuclear medicine physicians. Even with strong trial evidence, adoption stalls outside major academic medical centers and high-income countries. Rural patients face long travel distances, insurance coverage remains inconsistent, and supply chain issues with radiopharmaceuticals persist, creating a two-tier system where the technology's benefits flow primarily to those already closest to care.

Discussed by: American Society of Clinical Oncology researchers; health economists studying PET infrastructure costs
Consensus —
3

PSMA theranostics reshape prostate cancer from screening through treatment

PSMA PET scanning for diagnosis pairs with PSMA-targeted radioligand therapy (Pluvicto) for treatment, creating a complete pipeline where the same molecular target is used to find, characterize, and destroy prostate cancer. Clinical trials expand Pluvicto's use to earlier-stage disease, and the combination of PSMA-guided screening plus PSMA-targeted treatment reduces prostate cancer mortality while avoiding the collateral damage of aggressive surgery and radiation in men with localized tumors.

Discussed by: Novartis (which invested $2.1 billion in Pluvicto); nuclear medicine researchers at Peter Mac and St Vincent's Hospital
Consensus —
4

Long-term follow-up reveals missed cancers, tempering enthusiasm

The PRIMARY2 trial's initial six-month results are promising, but the study will follow patients for two years. If longer follow-up reveals that some clinically significant cancers were missed by the PSMA-negative pathway, enthusiasm could cool and guidelines could limit the technology's role to a supplement rather than a replacement for biopsy. The 12% versus 16% detection gap, which was noninferior at six months, could widen over time.

Discussed by: Oncology skeptics and guideline committees awaiting two-year PRIMARY2 follow-up data
Consensus —

Historical Context

MRI replaces blind biopsies for prostate cancer (2017-2021)

2017-2021

What Happened

The PRECISION trial in 2018 and the STHLM3-MRI trial in 2021 demonstrated that magnetic resonance imaging could be used to target prostate biopsies rather than sampling the gland blindly. The STHLM3 trial, enrolling over 12,000 men in Stockholm, showed that combining a risk-prediction blood test with MRI reduced overdiagnosis while maintaining detection of dangerous cancers.

Outcome

Short Term

MRI-targeted biopsy became the standard of care in many countries, reducing the number of men biopsied by roughly 48% and cutting detection of harmless cancers by 62%.

Long Term

MRI set the precedent that imaging could safely replace some biopsies, but it still left a large group of men with ambiguous results who were sent for biopsy anyway. PRIMARY2 addresses exactly this gap.

Why It's Relevant Today

PRIMARY2 picks up where MRI-targeted biopsy left off. The trial specifically enrolled men whose MRI results were inconclusive, showing that adding PSMA PET to the diagnostic pathway can resolve ambiguity that MRI alone cannot.

PSA screening controversy and the overdiagnosis crisis (1994-2018)

1994-2018

What Happened

After the FDA approved the PSA blood test in 1994, prostate cancer diagnoses soared. By the 2000s, evidence showed that for every man whose life was saved by early detection, many more were diagnosed with slow-growing cancers that would never have harmed them. In 2012, the US Preventive Services Task Force recommended against routine PSA screening entirely, triggering a sharp decline in testing.

Outcome

Short Term

Screening rates fell, and some men who would have benefited from early detection were diagnosed later with more advanced disease. The task force partially reversed its position in 2018.

Long Term

The controversy created lasting public confusion about prostate cancer screening and demonstrated the urgent need for tools that could distinguish aggressive cancers from indolent ones, rather than simply detecting the presence of any cancer.

Why It's Relevant Today

PSMA PET directly addresses the central problem that made PSA screening controversial. Rather than simply flagging elevated protein levels that could indicate anything from cancer to a benign enlarged prostate, PSMA imaging identifies cells with the molecular signature of aggressive cancer. PRIMARY2's finding that diagnoses of clinically insignificant cancer dropped from 32% to 14% shows the technology can reduce exactly the overdiagnosis that undermined confidence in prostate screening.

Mammography screening debate and the quest for precision cancer detection (1970s-present)

1970s-present

What Happened

Mammography screening for breast cancer faced decades of debate remarkably similar to the PSA controversy: early detection saved some lives but also led to overdiagnosis of ductal carcinoma in situ and other conditions that might never progress. Estimates suggest 20-30% of screen-detected breast cancers represent overdiagnosis.

Outcome

Short Term

Screening guidelines were revised repeatedly as different countries weighed the tradeoff between early detection and overtreatment differently.

Long Term

The field has moved toward more precise imaging (contrast-enhanced mammography, breast MRI) and molecular markers to distinguish aggressive from indolent lesions, mirroring the trajectory now underway in prostate cancer.

Why It's Relevant Today

The prostate cancer screening pathway is following a pattern established by breast cancer: from blunt population-level screening to increasingly precise molecular and imaging tools that reduce harm while preserving the benefits of early detection. PSMA PET represents the prostate cancer equivalent of this evolution.

Sources

(10)
+4
Human Progress Urology Times ecancer Medical Xpress Peter MacCallum Cancer Centre The Lancet Frontiers in Oncology Journal of Nuclear Medicine Pharmaceuticals (PMC) Pharmaceuticals (PMC)