Being diagnosed with prostate cancer does not always mean that treatment needs to start immediately.

Many prostate cancers grow very slowly and may never cause symptoms or threaten a man’s life. For carefully selected men, active surveillance allows the cancer to be closely monitored while avoiding, or at least delaying, treatments such as surgery or radiation therapy.

Importantly, active surveillance does not mean ignoring the cancer. It is a structured programme of PSA testing, clinical review, prostate MRI and, when appropriate, repeat prostate biopsy. If there are signs that the cancer is becoming more significant, treatment can be recommended while the disease is still potentially curable.

Current international guidelines consider active surveillance the preferred or standard management approach for most suitable men with low-risk localised prostate cancer, and it may also be considered in carefully selected men with favourable intermediate-risk disease.

What Is Active Surveillance?

Active surveillance is a management strategy for prostate cancer in which curative treatment is deliberately postponed while the cancer is carefully monitored.

The aim is simple:

Avoid unnecessary treatment and its potential side effects, without compromising the opportunity for cure if the cancer changes.

This is particularly relevant because prostate cancer behaves very differently from one man to another. Some cancers are aggressive and require treatment, while others may remain small and slow-growing for many years.

Australian patient guidance describes active surveillance as close monitoring of low-risk prostate cancer that is not causing symptoms, with treatment initiated if investigations indicate that the cancer is becoming more aggressive.

Who Qualifies for Active Surveillance?

Active surveillance is most commonly recommended for men with low-risk prostate cancer.

Typical features include:

• Cancer confined to the prostate
• Grade Group 1 / Gleason score 3+3=6
• PSA generally less than 10 ng/mL
• Clinical stage T1 to T2a
• Relatively small volume of cancer on prostate biopsy
• Favourable findings on multiparametric MRI
• A PSA density that supports low-volume disease
• No clinical or imaging evidence suggesting more aggressive cancer

The AUA/ASTRO risk classification defines low-risk disease as PSA below 10 ng/mL, Grade Group 1 and clinical stage T1–T2a. For these patients, active surveillance is recommended as the preferred management strategy.

However, no single number determines suitability. Age, general health, family history, MRI findings, PSA density, biopsy findings, life expectancy and personal preferences all contribute to the decision.

Can Men With Gleason 3+4 / Grade Group 2 Cancer Have Active Surveillance?

Sometimes.

Active surveillance is increasingly considered for carefully selected men with favourable intermediate-risk prostate cancer, particularly when there is only a small amount of Gleason pattern 4 disease.

The 2026 European Association of Urology guidelines support active surveillance for selected men with favourable Grade Group 2 cancer. Features favouring surveillance include a small amount of pattern 4 disease, PSA below 10 ng/mL, limited tumour volume on biopsy and favourable imaging.

Similarly, AUA/ASTRO guidance suggests that favourable intermediate-risk patients with low PSA density, low tumour volume and a low percentage of Gleason pattern 4 disease may be considered for active surveillance.

These men require careful counselling because their risk of progression is higher than for men with Grade Group 1 disease.

Active surveillance is generally not appropriate for Grade Group 3 or higher-risk prostate cancer in men otherwise suitable for curative treatment.

What Happens Before Starting Active Surveillance?

The first step is making sure that the cancer really is suitable for surveillance.

Assessment may include:

PSA and PSA Density

PSA is considered together with prostate volume to calculate the PSA density.

A relatively low PSA density, commonly around less than 0.15 ng/mL/cc, provides additional reassurance in men being considered for surveillance, although it should not be interpreted as an absolute cut-off in isolation.

Multiparametric MRI of the Prostate

A high-quality multiparametric MRI (mpMRI) provides important information about:

• The location of the tumour
• Tumour size
• Suspicious areas within the prostate
• Possible extension outside the prostate
• Areas that should be targeted during biopsy

MRI has become an important part of modern active surveillance, but MRI alone does not completely replace prostate biopsy.

Review or Confirmation of the Biopsy

The initial biopsy determines the Grade Group, Gleason score and volume of cancer.

Depending on how the original diagnosis was made, a confirmatory biopsy may be recommended. MRI-targeted biopsies can specifically sample suspicious lesions, while systematic or regional biopsies assess other areas of the prostate.

How Is Active Surveillance Performed?

Active surveillance is an ongoing programme rather than a single test.

The exact protocol varies according to the patient’s age, cancer characteristics, previous investigations and the treating urologist or institution.

A typical programme may include:

PSA Testing

PSA is usually measured approximately every 3–6 months initially, although intervals may become longer in men with very stable disease.

Current EAU guidance recommends PSA testing at least every six months, while Australian Cancer Council information describes PSA testing every 3–6 months.

The trend in PSA is usually more informative than one isolated reading.

An unexpected rise does not automatically mean that the cancer has progressed. PSA can fluctuate because of benign prostate enlargement, inflammation, infection and other factors.

For this reason, an unexpected PSA rise will often be repeated before further decisions are made.

Clinical Review

Regular appointments allow your urologist to review:

• PSA changes
• Urinary symptoms
• General health
• Examination findings
• MRI results
• Whether further investigation is required

A digital rectal examination may form part of surveillance, although its frequency can be individualised.

Repeat Prostate MRI

Repeat mpMRI may be performed periodically or earlier if PSA or other findings become concerning.

MRI allows comparison with previous scans to determine whether a lesion is:

• Stable
• Increasing in size
• Becoming more suspicious
• Showing features suggesting progression

Importantly, a change on MRI will often lead to a repeat biopsy rather than automatically triggering treatment. The EAU recommends confirming suspected histological progression before changing treatment strategy where appropriate.

Repeat Prostate Biopsy

Repeat biopsy remains an important component of active surveillance.

The frequency varies according to individual risk, previous MRI and biopsy findings and the surveillance protocol being followed.

The biopsy may involve:

• Targeted biopsy of an MRI abnormality
• Systematic sampling
• A combination of targeted and regional/systematic biopsies

Modern surveillance programmes increasingly tailor biopsy frequency according to the individual’s risk rather than applying exactly the same schedule to every patient.

What Are We Looking for During Surveillance?

The purpose of surveillance is to identify reclassification or progression before the cancer becomes difficult to cure.

Your urologist will be looking for several possible warning signs.

These include:

Increasing cancer grade

For example, a cancer initially classified as Grade Group 1 may subsequently demonstrate a significant amount of Gleason pattern 4 disease.

Increasing cancer volume

More biopsy samples may contain cancer, or individual samples may contain a greater amount of cancer.

Changes on MRI

An existing lesion may enlarge or become more suspicious, or a new lesion may appear.

Persistent PSA changes

A progressively increasing PSA, particularly when accompanied by increasing PSA density or concerning MRI findings, may trigger further investigation.

Clinical progression

Changes on examination or other investigations may suggest that the cancer is no longer behaving as expected.

When Should Active Surveillance Stop?

Active surveillance should generally continue for as long as the cancer remains suitable for surveillance and curative treatment remains relevant.

The decision to move to treatment should ideally be based on the overall picture rather than PSA alone.

Treatment may be recommended when there is:

• Significant upgrading of the cancer on repeat biopsy
• Increasing amounts of higher-grade cancer
• Significant increase in tumour volume
• Concerning progression on MRI confirmed by appropriate investigation
• Evidence suggesting progression beyond the original low-risk category
• A change in the patient’s preference after informed discussion

AUA/ASTRO guidance recommends that significantly higher-volume or higher-grade disease on surveillance biopsy should prompt discussion about definitive therapy.

What Happens If the Cancer Progresses?

The important concept behind active surveillance is that treatment has been postponed, not abandoned.

If investigations demonstrate clinically significant progression, curative treatment can be considered.

Depending on the man’s age, general health, cancer characteristics and preferences, options may include:

Radical Prostatectomy

Surgical removal of the prostate, increasingly performed using robotic-assisted radical prostatectomy.

Focal therapy

Nanoknife electroporation

ProFocal laser ablation

Radiation Therapy

Options may include:

• External beam radiation therapy
• Stereotactic radiation therapy in appropriate patients
• Brachytherapy in selected cases
• Radiation combined with hormonal therapy where clinically indicated

Other Selected Treatments

In carefully selected circumstances, other approaches may be discussed. The evidence for focal ablative therapies remains less mature than that for established treatments such as surgery and radiation therapy, and suitability needs individual assessment.

What Are the Benefits of Active Surveillance?

For appropriately selected men, the major advantage is avoiding treatment that may never have been necessary.

Avoiding or Delaying Treatment Side Effects

Radical treatment can potentially cause:

• Urinary incontinence
• Erectile dysfunction
• Ejaculatory changes
• Urinary symptoms
• Bowel symptoms following some forms of radiation therapy

Active surveillance allows men to maintain their existing urinary, sexual and bowel function for longer.

Maintaining Quality of Life

Many men can continue normal work, exercise, travel and sexual activity without the recovery period or functional consequences associated with immediate treatment.

Avoiding Overtreatment

Some low-risk prostate cancers may never become clinically significant during a man’s lifetime.

Treating every prostate cancer immediately would therefore expose some men to treatment complications without providing a meaningful survival advantage.

Treatment Remains Available

Active surveillance preserves the opportunity for curative treatment if the cancer subsequently demonstrates significant progression.

Long-term outcomes from well-conducted active surveillance programmes are reassuring. The EAU reports 10-year prostate cancer-specific survival rates of approximately 98–100% in active surveillance cohorts, although outcomes depend on appropriate patient selection and follow-up.

What Are the Risks of Active Surveillance?

Active surveillance is not completely risk-free.

The Cancer May Progress

Some cancers initially thought to be low risk will subsequently demonstrate more aggressive features.

In fact, a significant proportion of men are eventually reclassified during long-term surveillance and may proceed to treatment.

The Initial Biopsy May Underestimate the Cancer

A prostate biopsy samples only part of the prostate.

Occasionally, higher-grade cancer may already be present but was not captured during the original biopsy. Modern MRI and targeted biopsy techniques help reduce this risk but cannot eliminate it completely.

Small Risk of Losing the Optimal Window for Treatment

This is one of the main reasons that regular follow-up is essential.

In appropriately selected men who comply with structured surveillance, the risk is low, but surveillance must be active rather than passive.

Repeat Investigations

Active surveillance may involve:

• Repeated blood tests
• MRI scans
• Urology appointments
• Repeat prostate biopsies

Biopsies can cause discomfort, bleeding and infection, although contemporary transperineal biopsy techniques can substantially reduce the risk of serious infection.

Psychological Impact

Some men find living with untreated cancer surprisingly easy. Others find it difficult.

Anxiety may occur around:

• PSA tests
• MRI scans
• Repeat biopsies
• Waiting for results
• Concern that the cancer may be progressing

For some men, the psychological burden becomes an important factor when deciding whether to remain on surveillance.

Active Surveillance Is Not the Same as Watchful Waiting

These terms are sometimes confused, but they describe different approaches.

Active surveillance is generally used for men with potentially curable prostate cancer. The cancer is actively monitored, with the intention of offering curative treatment if clinically significant progression occurs.

Watchful waiting is more commonly used in older men or men with significant other medical conditions where prostate cancer is unlikely to affect life expectancy. Monitoring is less intensive, and treatment is generally introduced to control symptoms rather than with the intention of cure.

Does Active Surveillance Mean Doing Nothing?

No.

This is perhaps the most important misconception about active surveillance.

A better description might be:

“Treatment if and when it becomes necessary.”

The cancer is being monitored carefully so that unnecessary treatment can be avoided while retaining the opportunity to intervene if its behaviour changes.

For the right patient, this can provide an excellent balance between cancer control and preservation of quality of life.

The Bottom Line

Active surveillance has become an established standard of care for appropriately selected men with low-risk prostate cancer and can also be considered for some men with carefully selected favourable intermediate-risk disease.

The decision should take into account:

• PSA and PSA density
• Grade Group and Gleason score
• Amount of cancer found on biopsy
• MRI findings
• Clinical stage
• Age and life expectancy
• General health
• Family and genetic risk factors
• Personal preferences

Most importantly, active surveillance requires a partnership between the patient and his urologist.

The goal is not simply to avoid treatment.

The goal is to avoid treatment that is unnecessary, while identifying the point at which treatment becomes worthwhile.

This information is intended for general education and does not replace individual medical advice. Recommendations for prostate cancer management should be based on a detailed assessment of the individual patient, pathology, PSA results, imaging, general health and personal preferences.