Active Surveillance for Prostate Cancer: Who It Is For, How Monitoring Works and When Treatment May Be Needed

By Mr Neil Haldar, Consultant Urological Surgeon

Being told that you have prostate cancer naturally creates an expectation that treatment should begin as quickly as possible. For some men, however, immediate treatment may cause more harm than the cancer itself.

Many prostate cancers are slow-growing. Some remain confined to the prostate for many years and may never cause symptoms or shorten a man’s life. Treating every one of these cancers immediately would expose a considerable number of men to the possible side effects of surgery or radiotherapy without providing a clear medical benefit.

Active surveillance offers a different approach. Rather than treating the cancer straight away, the medical team monitors it carefully and recommends treatment only if there is convincing evidence that the disease is becoming more significant.

This is not the same as ignoring the cancer or simply waiting for symptoms to appear. Active surveillance is a structured medical programme involving PSA tests, clinical reviews, MRI scans and, where necessary, repeat prostate biopsies. Its purpose is to avoid unnecessary treatment while preserving the opportunity for cure should the cancer change.

In brief

Active surveillance may be appropriate when prostate cancer:

• appears to be confined to the prostate;
• is low-grade and small in volume;
• is unlikely to cause harm in the immediate future;
• can be monitored safely;
• remains potentially curable if treatment becomes necessary.

It is most commonly recommended for men with Grade Group 1 prostate cancer, previously described as Gleason 3+3=6. It may also be considered for carefully selected men with favourable Grade Group 2, or Gleason 3+4, disease.

Active surveillance does not mean that treatment will never be needed. Some men remain under surveillance indefinitely, while others eventually undergo surgery or radiotherapy because tests show that their cancer has changed. The aim is to treat only those men who are likely to benefit and to do so while the cancer remains curable.

What is active surveillance?

Active surveillance is a planned strategy for managing localised prostate cancer without immediate surgery or radiotherapy.

The cancer is monitored at regular intervals using a combination of:

• PSA blood tests;
• review of symptoms and general health;
• digital rectal examination in some programmes;
• multiparametric MRI;
• repeat prostate biopsy when indicated.

Treatment is reconsidered if these assessments suggest that the cancer is more extensive, higher-grade or more biologically significant than was originally thought.

Active surveillance should therefore be thought of as treatment deferred until it is needed, rather than an absence of treatment.

European guidance recommends active surveillance as the standard approach for suitable men with low-risk prostate cancer and also recognises it as an option for selected men with favourable intermediate-risk disease.

How is active surveillance different from watchful waiting?

The terms active surveillance and watchful waiting are sometimes used interchangeably, but they describe different approaches.

Active surveillance

Active surveillance is normally offered to men whose cancer is potentially curable but does not currently appear to require treatment.

The patient remains eligible for curative treatment, most commonly radical prostatectomy or radiotherapy. Follow-up is designed to detect significant change at a stage when treatment is still likely to be effective.

Watchful waiting

Watchful waiting is more commonly used for men whose age, general health or other medical conditions mean that curative treatment is unlikely to improve their life expectancy or quality of life.

Follow-up is generally less intensive. Treatment is introduced if the cancer begins causing symptoms, with the emphasis on controlling the disease and maintaining comfort rather than achieving cure.

A man may begin on active surveillance and later move to watchful waiting as he becomes older or develops other health problems. This does not necessarily mean that the cancer has progressed. It may simply mean that the balance between the benefits and burdens of further investigation has changed.

Why can prostate cancer sometimes be left untreated?

Prostate cancers do not all behave in the same way.

Some are aggressive and require prompt treatment. Others grow very slowly and have a low probability of spreading beyond the prostate. Modern PSA testing, MRI and prostate biopsy frequently detect small cancers that might never have been discovered in an earlier era.

This creates a problem of potential overtreatment.

Radical prostatectomy and radiotherapy can be highly effective treatments, but they may also affect:

• erectile function;
• urinary continence;
• ejaculation and fertility;
• bowel function after radiotherapy;
• general wellbeing during treatment and recovery.

Where the cancer has a very low probability of causing harm, these side effects may outweigh the immediate benefit of treatment.

Active surveillance creates time in which doctors can observe the cancer’s behaviour. A man can preserve his urinary and sexual function for as long as the cancer remains stable, while retaining the option of curative treatment if there is convincing evidence of progression.

Who may be suitable for active surveillance?

There is no single PSA level, MRI score or biopsy result that determines suitability. The decision depends on how all the clinical findings fit together.

Doctors will usually consider:

• the Grade Group and Gleason score;
• the amount of cancer found in the biopsy samples;
• the proportion of any Gleason pattern 4 disease;
• the PSA level;
• PSA density;
• clinical stage;
• MRI appearance;
• whether the MRI and biopsy findings agree;
• adverse pathological features;
• age and estimated life expectancy;
• general health and other medical conditions;
• family history and, in selected cases, genetic factors;
• the patient’s priorities and willingness to attend follow-up.

Grade Group 1 prostate cancer

Men with Grade Group 1 cancer are the most established candidates for active surveillance.

Grade Group 1 corresponds to a Gleason score of 3+3=6. Despite the number six, this is the lowest grade normally assigned to a prostate cancer on biopsy. Properly assessed Grade Group 1 disease has a very low risk of spreading over the short to medium term.

A man with Grade Group 1 disease, a reassuring MRI, a favourable PSA density and a relatively small amount of cancer on biopsy will often be an excellent candidate for surveillance.

Selected Grade Group 2 prostate cancer

Active surveillance may also be suitable for some men with Grade Group 2, or Gleason 3+4=7, prostate cancer.

This requires more careful selection because Grade Group 2 contains an element of Gleason pattern 4, which is biologically more significant than pattern 3.

Features that may support surveillance include:

• only a small amount of pattern 4;
• a relatively low PSA;
• favourable PSA density;
• low-volume cancer on biopsy;
• disease confined to the prostate;
• a small or limited MRI abnormality;
• agreement between the MRI and biopsy findings;
• absence of cribriform or intraductal carcinoma.

European guidance gives selected low-volume Grade Group 2 disease as an example of favourable intermediate-risk cancer that may be considered for surveillance, while recognising a higher long-term risk of progression than with Grade Group 1 disease.

The presence of Grade Group 2 disease does not automatically make surveillance unsafe, but it makes careful counselling and reliable follow-up particularly important.

Who may not be suitable?

Active surveillance is less likely to be appropriate where there is evidence of biologically significant or more extensive disease.

Features that may argue against surveillance include:

• Grade Group 3 or higher cancer;
• a substantial amount of Gleason pattern 4;
• cribriform architecture;
• intraductal carcinoma;
• extensive cancer in systematic biopsy samples;
• evidence that the cancer extends beyond the prostate;
• rapidly changing findings confirmed through further investigation;
• substantial disagreement between an apparently reassuring biopsy and a highly suspicious MRI;
• inability or unwillingness to attend structured follow-up.

Cribriform and intraductal patterns are particularly important. Current European guidance recommends excluding men with these pathological features from active-surveillance programmes, even where the overall Grade Group might otherwise appear favourable.

A highly suspicious MRI lesion does not, by itself, make surveillance impossible. However, it should be carefully sampled, and the imaging, pathology, PSA density and clinical findings should be reviewed together before a decision is made.

The importance of life expectancy and general health

A man’s age is relevant, but age alone should not determine treatment.

What matters more is his overall health and estimated life expectancy.

A fit man in his seventies may have many years of good-quality life ahead of him and may benefit from a surveillance programme that preserves curative treatment as an option. Conversely, a younger man with serious competing health problems may gain little from repeated biopsies or radical treatment.

As life expectancy falls, the benefit of detecting small changes in a slow-growing cancer also falls. At that point, it may be appropriate to move from active surveillance to watchful waiting.

The role of multiparametric MRI

Multiparametric MRI has significantly improved the way prostate cancer is assessed and monitored.

An MRI can provide information about:

• the location of a suspicious area;
• the size of the visible lesion;
• whether the abnormality has well-defined or more concerning features;
• whether there are signs that the cancer extends outside the prostate;
• which areas should be targeted during biopsy.

MRI-directed biopsy reduces the chance that a clinically significant cancer will be missed during initial assessment. It also helps doctors judge whether biopsy findings are consistent with the imaging appearance.

During surveillance, MRI may be repeated to look for changes in the size or characteristics of a known lesion.

However, an MRI scan cannot reliably replace pathology in every patient. An apparent change on MRI usually leads to further assessment and often repeat biopsy. It should not automatically lead to surgery or radiotherapy.

Current European guidance recommends that progression on MRI should be confirmed histologically before the treatment strategy is changed.

Is a confirmatory biopsy always necessary?

Historically, most active-surveillance protocols included a confirmatory biopsy during the first year. This was intended to identify men whose original biopsy had missed a higher-grade area of cancer.

A confirmatory assessment remains important, but a repeat biopsy is not automatically necessary for every man.

Where the original diagnostic pathway included:

• high-quality multiparametric MRI;
• targeted sampling of suspicious areas;
• appropriate sampling around the MRI lesion;
• adequate systematic biopsy where required;

the risk of significant undersampling is lower. In such circumstances, the need and timing of another biopsy may be individualised.

Where the original diagnosis was made without MRI, or where the MRI and biopsy findings do not agree, repeat MRI-informed biopsy is more likely to be recommended. European guidance states that a separate confirmatory biopsy may be omitted in men who have already undergone upfront MRI with appropriate targeted and perilesional sampling.

What does active surveillance involve?

There is no single surveillance schedule that is correct for every man.

Protocols vary between hospitals and are increasingly adapted according to individual risk. A man with a very small Grade Group 1 cancer, stable PSA density and reassuring MRI may require less intensive follow-up than a man with selected Grade Group 2 disease.

A typical programme may include the following.

PSA testing

PSA is usually checked several times during the first year and then approximately every six months, although the precise interval varies.

The trend is often more informative than a single result. Doctors may consider:

• the overall direction of PSA;
• PSA density;
• the speed of change;
• PSA doubling time;
• prostate size;
• possible benign causes of fluctuation.

A PSA rise does not necessarily mean that the cancer has progressed.

Clinical review

Regular review provides an opportunity to discuss:

• PSA results;
• urinary symptoms;
• changes in general health;
• concerns about the surveillance programme;
• whether the patient’s priorities have changed.

A digital rectal examination may form part of follow-up, although its use and frequency vary as MRI-led surveillance becomes more established.

Repeat MRI

MRI may be repeated at a planned interval or brought forward if:

• PSA rises persistently;
• PSA density becomes less favourable;
• examination findings change;
• the original biopsy and MRI were discordant;
• there is another reason to suspect progression.

NICE currently describes a protocol involving MRI at approximately 12 to 18 months, with further MRI or biopsy where there is concern about clinical or PSA changes. Exact practice varies between centres.

Repeat biopsy

A repeat biopsy may be recommended where:

• the initial diagnostic assessment may have undersampled the cancer;
• MRI shows a new lesion;
• an existing MRI lesion appears to have changed;
• PSA kinetics are concerning;
• the clinical findings no longer fit the original diagnosis;
• a scheduled biopsy forms part of the local surveillance protocol.

Some men with stable MRI, persistently favourable PSA density and otherwise low-risk disease may be able to have longer intervals between biopsies. European guidance nevertheless continues to regard repeat biopsy as an important part of surveillance for many men.

An illustrative monitoring schedule

The following is an example rather than a rigid protocol:

Assessment	Possible timing	Purpose
PSA blood test	Every 3–4 months initially, then approximately every 6 months	Monitor the pattern of PSA change
Clinical review	Usually every 6–12 months	Review results, health and patient concerns
Digital rectal examination	Sometimes annually	Look for a clinically detectable change
Multiparametric MRI	Often at 12–18 months, periodically thereafter or when concern arises	Assess radiological stability
Confirmatory biopsy	Selected patients, often during the first year	Exclude significant initial undersampling
Surveillance biopsy	Risk-adapted or triggered by other findings	Look for pathological reclassification

The exact schedule should be based on the original diagnostic pathway, Grade Group, PSA density, MRI appearance, age, health and local clinical protocol. NICE and European guidance differ in some details, illustrating why surveillance should be individualised rather than reduced to a single universal timetable.

What happens if PSA rises?

A rising PSA understandably causes anxiety, but it is important not to interpret the result in isolation.

PSA is produced by both benign and cancerous prostate tissue. It may rise because of:

• benign enlargement of the prostate;
• inflammation or infection;
• urinary retention;
• recent instrumentation;
• ejaculation shortly before the test;
• natural biological and laboratory variation;
• progression of prostate cancer.

The first step may be to repeat the PSA under standardised conditions. PSA density may also be recalculated by comparing the PSA level with the volume of the prostate on imaging.

Where the rise is persistent or the PSA doubling time becomes concerning, MRI and repeat biopsy may be recommended. Current European guidance advises MRI and repeat biopsy where PSA is rising rapidly, but recommends basing a change to treatment primarily on biopsy-confirmed progression rather than PSA alone.

What changes may lead to treatment?

The decision to leave active surveillance should not usually be based on a single small fluctuation.

Treatment may be recommended where there is convincing evidence that the cancer has become more significant. This may include:

• progression to Grade Group 3 or above;
• development of cribriform or intraductal carcinoma;
• a meaningful increase in the amount of cancer on systematic biopsy;
• increasing Gleason pattern 4;
• evidence of progression beyond the prostate;
• concerning MRI or PSA changes followed by biopsy confirmation;
• a combination of less dramatic changes that together alter the assessment of risk.

Patient preference is also important. Some men find that living with an untreated cancer causes persistent anxiety despite reassuring results. A patient who remains medically suitable for surveillance may still choose treatment after discussing the expected benefits and possible side effects.

Does any increase from Grade Group 1 to Grade Group 2 mean treatment is necessary?

Not necessarily.

In the past, any upgrading from Grade Group 1 to Grade Group 2 was often considered a reason to recommend treatment. More recent evidence has shown that a very small amount of favourable Grade Group 2 disease may still be compatible with surveillance.

The decision depends on:

• how much pattern 4 is present;
• whether it was found on targeted or systematic biopsy;
• the volume of disease;
• the MRI appearance;
• PSA density;
• whether adverse patterns are present;
• the patient’s age and priorities.

MRI-targeted biopsy can detect small areas of pattern 4 more accurately than older biopsy techniques. This means that an apparent upgrade does not always represent sudden biological progression; it may reflect more accurate sampling.

European guidance therefore states that progression to Grade Group 2 should not automatically be considered a reason to stop surveillance, particularly when a limited amount is detected on targeted biopsy.

What does the evidence show?

Several large prospective surveillance studies have reported very low rates of prostate-cancer death among properly selected men. Current European guidance reports highly favourable long-term cancer-specific survival across established active-surveillance cohorts.

The best-known randomised evidence comes from the UK ProtecT trial, which compared:

• PSA-led active monitoring;
• radical prostatectomy;
• radiotherapy.

At a median follow-up of 15 years, prostate-cancer mortality was low in all three groups and did not differ significantly. Death from prostate cancer occurred in 3.1% of men allocated to active monitoring, 2.2% allocated to surgery and 2.9% allocated to radiotherapy.

However, metastases were more common in the active-monitoring group, occurring in 9.4%, compared with 4.7% after surgery and 5.0% after radiotherapy. Clinical progression was also more frequent with monitoring.

These findings require careful interpretation.

ProtecT did not use contemporary active surveillance. Recruitment began before modern multiparametric MRI, image-targeted biopsy and today’s more precise risk-stratification methods were routinely available. Its monitoring protocol was predominantly PSA-led and was less intensive than a modern MRI-informed surveillance programme. The trial therefore supports the safety of avoiding immediate treatment in many men, but it should not be treated as a direct test of present-day active surveillance.

The central message is not that surveillance carries no risk. It is that many men with appropriately selected localised prostate cancer can safely defer treatment, often for years, without losing the opportunity for cure.

What are the benefits of active surveillance?

Avoiding unnecessary treatment

Some men on surveillance will never need prostate cancer treatment. They avoid the physical burden and side effects of surgery or radiotherapy altogether.

Preserving urinary and sexual function

As no radical treatment is given while the cancer remains stable, surveillance avoids treatment-related urinary incontinence, erectile dysfunction and bowel effects during that period.

Retaining the possibility of cure

Active surveillance is designed to detect clinically important change while radical treatment remains possible.

Allowing time for an informed decision

A diagnosis of cancer can create pressure to make an immediate decision. Surveillance allows time to understand the disease, consider the options and decide what matters most to the individual patient.

Adapting treatment to the behaviour of the cancer

Rather than assuming that every prostate cancer will become dangerous, surveillance uses evidence from follow-up to identify which cancers genuinely require intervention.

What are the disadvantages and risks?

Initial misclassification

No biopsy can sample every part of the prostate. A more significant area of cancer may occasionally be missed at diagnosis. MRI-targeted and appropriately performed biopsy reduce this risk but do not eliminate it.

Biological progression

There remains a small possibility that the cancer will progress between assessments. This is why active surveillance must be structured and why attending follow-up is essential.

Repeat investigations

MRI scans, PSA tests and biopsies can be burdensome. A prostate biopsy may cause temporary bleeding, discomfort, difficulty passing urine or infection, although the exact risks depend partly on the biopsy technique.

Anxiety

Some men find it difficult to live with a known but untreated cancer. Anxiety may increase around PSA tests, scans and clinic appointments.

Treatment may still be needed

Surveillance defers treatment; it does not guarantee that treatment will never be necessary. For some men, the main benefit is several years without treatment rather than lifelong avoidance.

The psychological impact of surveillance

Choosing active surveillance can feel counterintuitive. Many patients have grown up with the belief that cancer should always be removed or treated immediately.

Clear communication is therefore as important as the monitoring protocol itself.

Patients need to understand:

• why their cancer is considered suitable for surveillance;
• what the individual tests can and cannot show;
• how frequently follow-up will occur;
• which changes would trigger further investigation;
• which findings would make treatment advisable;
• whom to contact if a test or appointment is delayed.

Some anxiety before PSA tests or scans is normal. Persistent anxiety that materially affects daily life should be discussed with the clinical team. Additional explanation, support or psychological help may allow a man to continue surveillance confidently. For others, anxiety may remain unacceptable and treatment may be a reasonable personal choice after balanced counselling.

Active surveillance is not “doing nothing”

A successful active-surveillance programme depends on partnership.

The clinical team must provide:

• a clear follow-up schedule;
• reliable review of results;
• access to MRI and biopsy when required;
• consistent communication;
• an agreed plan for responding to change.

The patient must:

• attend PSA tests and appointments;
• undergo recommended imaging or biopsy;
• ensure that missing or delayed results are followed up;
• report important new symptoms;
• remain involved in decisions about his care.

A man who cannot reliably attend follow-up may not be a suitable candidate, even if the cancer itself appears favourable.

What treatment is available if the cancer progresses?

If treatment becomes necessary, the principal established curative options are:

Radical prostatectomy

This involves removing the prostate and seminal vesicles. It may be performed using robotic-assisted or open surgery, although robotic surgery is now widely used in the UK.

Radiotherapy

Options may include external-beam radiotherapy or, in selected patients, brachytherapy. Hormone treatment may be combined with radiotherapy depending on the risk category.

Focal therapy

Focal treatment aims to treat the significant area of cancer while preserving the remainder of the prostate. It may be discussed in carefully selected cases at specialist centres, but its long-term comparative evidence is less mature than that for surgery and radiotherapy.

European guidance recommends that focal or whole-gland ablative treatments such as HIFU or cryotherapy should generally be delivered within clinical trials or prospective registries rather than treated as established equivalents to surgery and radiotherapy.

The appropriate treatment depends on the location and extent of the cancer, urinary and sexual function, general health, previous treatment and personal priorities.

Questions to ask your urologist

Men considering active surveillance may find it helpful to ask:

1. What is my Grade Group and Gleason score?
2. How much cancer was found in my biopsy?
3. Is any cribriform or intraductal cancer present?
4. What did my MRI show?
5. Do the MRI and biopsy findings agree?
6. What is my PSA density?
7. Am I considered low-risk or favourable intermediate-risk?
8. Would you recommend active surveillance in my particular case?
9. Do I need a confirmatory biopsy?
10. How often will my PSA be measured?
11. When will my MRI be repeated?
12. What findings would lead you to recommend another biopsy?
13. What would make you advise treatment?
14. Who will review my results and contact me?
15. What are the advantages and disadvantages of surgery and radiotherapy should treatment later become necessary?

Frequently asked questions

Conclusion

Active surveillance is one of the most important developments in the modern management of prostate cancer.

It recognises that prostate cancer is not a single disease and that not every cancer found on PSA testing, MRI or biopsy requires immediate treatment. For men with low-risk and carefully selected favourable intermediate-risk disease, surveillance may preserve urinary, sexual and bowel function while retaining the option of cure.

The safety of this approach depends on three things:

1. accurate initial assessment;
2. disciplined and appropriately individualised monitoring;
3. honest, shared decision-making between the patient and clinical team.

MRI has made active surveillance more precise, but it has not removed the need to interpret imaging alongside PSA, PSA density, pathology and the patient’s wider circumstances. A PSA rise or MRI change should prompt investigation rather than automatic treatment, and limited Grade Group 2 disease does not always mean that surveillance must end.

For the right patient, active surveillance is not a lesser form of care. It is an active decision to avoid treatment that may not be needed while remaining ready to intervene if the behaviour of the cancer changes.

Further Reading

Prostate Cancer UK: Active surveillance

NHS: Treatment for prostate cancer

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By Mr Neil Haldar, Consultant Urological Surgeon

Last medically reviewed: August 2026

Next review: August 2027, or earlier if NICE publishes its revised active-surveillance protocol.

This article provides general clinical information and should not be used as a substitute for individual medical advice. The appropriate management of prostate cancer depends on the complete clinical picture and should be discussed with the treating urologist and multidisciplinary team.

Would You Like a Specialist Review of Your Prostate Cancer Results?

Being told that you have prostate cancer does not always mean that immediate treatment is necessary. The safest recommendation depends on the Grade Group, amount of cancer present, PSA density, MRI findings, biopsy details, general health and your own priorities.

I regularly see men who would like a specialist review after being advised to consider active surveillance, surgery or radiotherapy.

During a consultation, I can:

• review your PSA history, MRI and biopsy results;
• explain your Grade Group and individual risk factors;
• assess whether active surveillance appears appropriate;
• discuss whether further MRI or biopsy may be needed;
• compare surveillance with surgery and radiotherapy;
• provide a specialist second opinion before you make a treatment decision.

I have been a consultant in urological surgery since 2005 and have performed over 1,000 radical prostatectomies. My role is not to recommend surgery to every patient, but to help you understand whether treatment is necessary and, when it is, which approach is most appropriate.

Private consultations are available across Buckinghamshire, Berkshire and London. I see both self-pay patients and patients insured by the major UK private medical insurers.

Request a Prostate Cancer Consultation

Alternatively, call 07841 048975.

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