CompletedInterventional

CHRONOS: Comparative health research outcomes of novel surgery in prostate cancer

Prostate cancer is the most common cancer in UK men. Standard treatments, such as surgery to remove the prostate or radiotherapy, treat the entire gland. While these treatments are effective, they can cause lasting side effects, including erection problems and urine leakage. A newer approach, called focal therapy, treats only the cancer itself while leaving healthy prostate tissue alone. This is done by heating the cancer cells with sound waves (HIFU) or freezing them with tiny needles (cryotherapy). The CHRONOS study compares focal therapy directly with whole-gland treatments to see if it provides similar cancer control with fewer side effects. It also tests whether taking hormone tablets for a short time before focal therapy can shrink the tumour and improve results. The trial aims to help men make informed choices about prostate cancer treatments in the future.

At a glance

Status

Completed

Sponsor

Imperial College London

Enrolment target

120

Start

30 Nov 2019

Estimated completion

12 Nov 2021

Prostate cancer

What is this study about?

The prostate is a small gland located just below the bladder in men. When prostate cancer is diagnosed, standard treatment usually involves treating the entire gland. This is called radical therapy and includes either surgery to remove the prostate or radiotherapy to destroy it. While these treatments cure or control cancer effectively, they carry a risk of life-changing side effects, such as urinary incontinence, bowel problems, and erectile dysfunction.

Focal therapy is an alternative, less invasive approach. Instead of treating the whole prostate, it targets only the tumour. It uses either High-Intensity Focused Ultrasound (HIFU), which heats and destroys cancer cells with high-frequency sound waves, or cryotherapy, which freezes the cancer cells. Early studies suggest focal therapy causes fewer side effects, but larger clinical trials are needed to prove whether it controls cancer as well as standard treatments in the long term.

The CHRONOS trial is divided into two parts to answer these questions. In CHRONOS-A, participants are randomly assigned to receive either standard whole-gland therapy or targeted focal therapy. In CHRONOS-B, designed for men who definitely want focal therapy, participants receive focal therapy either on its own or alongside a 12-week course of hormone tablets to shrink the tumour beforehand.

Funded by Prostate Cancer UK and run across several NHS trusts, this study aims to give doctors and patients clear evidence about the benefits and trade-offs of targeted prostate treatments.

Key takeaways

CHRONOS compares targeted 'focal' therapy against standard whole-prostate surgery and radiotherapy.
Focal therapy aims to treat only the tumour, reducing side effects like bladder leakage and erection problems.
The study also tests whether short courses of hormone tablets improve focal therapy results.
The trial is open to UK men with localized, low-to-medium risk prostate cancer who have not had prior treatment.
The research is funded by Prostate Cancer UK and runs through December 2027.

Who may be eligible?

This trial is open to men aged 18 and over who have been newly diagnosed with low-to-medium risk prostate cancer that is contained within the prostate gland (or has only just begun to touch the prostate lining). Your diagnosis must be confirmed by a prostate biopsy and an MRI scan.

To be eligible, you must not have received any previous treatment for prostate cancer. You should also be physically well enough to undergo surgery, radiotherapy, or focal therapy, and have a PSA blood test result of 20 ng/ml or lower.

Men whose cancer has spread outside the prostate to other parts of the body, or who have already had treatment for prostate cancer, will not be eligible to take part. Your hospital specialist can review your scan and biopsy results to see if the trial is right for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am a man aged 18 or older.
I have been diagnosed with localized prostate cancer (not spread beyond the prostate).
I have not had any previous prostate cancer treatments.
My PSA blood test level is 20 ng/ml or lower.
I am fit enough to undergo surgery, radiotherapy, or focal treatment under anaesthetic.

Answer every question to see your result.

What does participation involve?

If you choose to take part, you can decide whether to join CHRONOS-A or CHRONOS-B. In CHRONOS-A, a computer randomly allocates you to receive either standard whole-gland treatment (surgery or radiotherapy) or focal therapy (HIFU or cryotherapy). In CHRONOS-B, all participants receive focal therapy, but a computer decides whether you take hormone tablets (bicalutamide or finasteride) for 12 weeks beforehand or proceed straight to treatment. Focal therapies and surgery are carried out in hospital under anaesthetic, while radiotherapy requires multiple outpatient visits. You will have regular check-ups, PSA blood tests, and scans over several years to monitor your health and recovery. The study runs until December 2027.

Potential risks and benefits

Taking part may not directly benefit your health compared with standard NHS care, but your participation helps doctors learn how best to treat future patients. All treatments carry risks. Whole-prostate treatments have well-known risks of urine leakage, bowel irritation, and erectile dysfunction. Focal therapy is designed to have fewer side effects, but its long-term cancer control is still being studied, and you might need repeat treatment in the future. The short course of hormone tablets can cause temporary side effects such as fatigue, reduced sex drive, and breast tenderness. You are free to leave the trial at any time without your regular NHS medical care being affected.

Locations (12)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Imperial College Healthcare NHS Trust
Unverified
London, England
University Hospital Southampton NHS Foundation Trust
Unverified
Southampton, England
Hampshire Hospitals NHS Foundation Trust
Unverified
Basingstoke, England
Ashford And St Peter's Hospitals NHS Foundation Trust
Unverified
Chertsey, England
Wexham Park Hospital
Unverified
Slough, England
Sunderland Royal Hospital
Unverified
Sunderland, England
Royal Marsden Hospital
Unverified
London, England
Frimley Park Hospital
Unverified
Frimley, England
Guys and St Thomas' Hospital
Unverified
London, England
Freeman Hospital
Unverified
Newcastle, England
Whittington Hospital
Unverified
London, England
Kingston Hospital
Unverified
Kingston Upon Thames, England

Common questions

What is the difference between radical therapy and focal therapy?

Radical therapy treats the entire prostate gland using surgery or radiation. Focal therapy treats only the cancer itself using heat or freezing, leaving the rest of the healthy prostate untouched.

Can I choose which treatment I receive?

You can choose whether to join CHRONOS-A or CHRONOS-B. Within your chosen group, treatment types are assigned randomly by a computer to ensure a fair comparison, although you can often choose between surgery or radiotherapy, or between HIFU or freezing.

Will focal therapy definitely stop my cancer?

Medium-term results are promising, but doctors do not yet know if focal therapy controls cancer as well as standard treatments in the long term. That is the main question this study aims to answer.

What happens if the cancer comes back after focal therapy?

Because healthy prostate tissue remains, you will be closely monitored. If cancer returns, you can often have further focal therapy or switch to standard treatments like surgery or radiotherapy.

Do I have to travel to London to take part?

Not necessarily. Although Imperial College London leads the trial, several NHS hospitals across the UK are participating, though some specific focal treatments may require travel to a specialist centre.

How to find out more

Thiagarajah Sasikaran

t.sasikaran@imperial.ac.uk +44 (0)20 7594 6017 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.