Condition category
Date applied
Date assigned
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Prospectively registered
Overall trial status
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Plain English Summary

Background and study aims
There are 12,500 new cases of kidney cancer every year in the UK and it is predicted that this will rise to 16,000 by 2035. The standard treatment for small kidney cancers is surgical removal of the cancer (partial nephrectomy). However, this is a complex surgery procedure and 1 in 20 patients develop complications such as leakage of urine into the abdomen, bleeding and bowel injury. An alternative treatment option is cryoablation, which involves killing cancer cells by freezing. It has fewer complications, faster recovery and gives equally good cancer control. Currently, cryoablation is mainly offered to elderly patients or patients with significant medical problems. It is not clear if it can also benefit other patients. A clinical trial comparing the two options may answer this question. The researchers want to see if patients are willing to be involved in such a trial by conducting a feasibility study first, which if successful will progress to a full trial. The aim of this study is to see whether patients with small renal cancers will take part in a study to compare cancer treatment by cryoablation with partial nephrectomy.

Who can participate?
Patients aged over 18 with small renal cancers

What does the study involve?
Participants are randomly allocated to be treated with cryotherapy or robot-assisted partial nephrectomy (standard care). Cryotherapy involves freezing of the tumour using percutaneous needles. Robot-assisted partial nephrectomy involves surgery to remove the tumour and leave the rest of the kidney behind. Follow-up for the purposes of this study is 6 months, but standard clinical follow up is at least 5 years.

What are the possible benefits and risks of participating?
It is hoped that cryoablation will help participants experience fewer side effects from treatment than if they had a partial nephrectomy, and, because cryoablation is a less invasive treatment, recovery after surgery will be quicker and participants will be able to go back sooner to their normal day to day life. However, this cannot be guaranteed as it is not known what the outcome of the study will be. This is why this study is being conducted and the information gathered from this study will hopefully help doctors to treat future patients diagnosed with a small renal mass better.

Where is the study run from?
Royal Free NHS Foundation Trust (UK)

When is the study starting and how long is it expected to run for?
April 2019 to April 2022

Who is funding the study?
National Institute for Health Research (NIHR) (UK)

Who is the main contact?
Maxine Tran

Trial website

Contact information



Primary contact

Miss Maxine Tran


Contact details

Specialist Centre for Kidney Cancer
Royal Free Hospital
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A feasibility study of a cohort embedded randomised controlled trial comparing NEphron-Sparing Treatment (NEST) for small renal masses


Study hypothesis

Patients with small renal cancers are willing to enter a treatment trial comparing surgery with cryoablation.

Ethics approval

Approved 05/02/2019, East Midlands - Derby Research Ethics Committee, The Old Chapel, Royal Standard Place, Nottingham, NG1 6FS, Tel: +44 (0)207 104 8109/(0)207 104 8237, Email:, ref: 19/EM/0004

Study design

Randomised; Both; Design type: Treatment, Surgery, Active Monitoring, Cohort study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Kidney cancer


Randomisation will be performed in blocks of 10 participants through the online system 'Sealed Envelope' ( to ensure allocation concealment.

1. Cryotherapy (intervention): Involves the freezing of the tumour by using percutaneous needles.
2. Robot-assisted partial nephrectomy (standard care): involves surgery to remove the tumour and leave the rest of the kidney behind.

Follow-up for the purposes of this feasibility trial will be 6 months, but standard clinical follow up will be at least 5 years.

Intervention type



Drug names

Primary outcome measure

Recruitment rate, measured using number of participants recruited per month during the study

Secondary outcome measures

1. Retention rate, measured using randomised participants retained and assessed with valid primary outcome data, measured annually
2. Health-related quality of life measured using EQ5D-5L prior to treatment and 3 months following treatment
3. Complications, blood transfusion, ITU admission and renal replacement requirement rates, measured using clinical records during hospital admission, 30 days post-operative and at 6 months
4. Length of hospital stay, time to return to pre-treatment activities, number of work days lost (in those who work), measured using clinical records and follow-up consultation (clinic or telephone) at 30 days and at 6 months
5. Costs incurred by health technologies, measured using NHS reference costs and also private and societal costs measured using patient completed questionnaire at time of treatment, at 30 days and at 6 months

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Inclusion criteria for study cohort:
1. Informed consent
2. Males and females
3. > 18 years of age
4. Diagnosed with renal mass <4 cm in size

Inclusion criteria for randomisation/interventional cohort:
1. Biopsy proven RCC
2. Tumours that are suitable for robot-assisted PN and CO

Participant type


Age group




Target number of participants

Planned Sample Size: 200; UK Sample Size: 200

Participant exclusion criteria

Exclusion criteria for study cohort:
1. Any of the above listed inclusion criteria not met
2. Patient unable to provide or indicate informed consent

Exclusion criteria for randomisation/interventional cohort:
Patients with any concurrent medical/surgical condition or indication, which would mean the SMDT recommends one treatment modality is more suitable than another, such as:
1. Myocardial Infarction in preceding 6/12
2. Pulmonary disease not allowing for prolonged anaesthesia
3. Multiple previous abdominal surgery/interventions, making surgical approach high risk
4. Performance status > = 2
5. Metastatic disease
6. Charlson co-morbidity index > 3
7. Patients with multifocal tumours
8. Patients with suspected or diagnosed with inherited kidney cancer susceptibility syndromes
9. Women that are pregnant or breastfeeding

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Royal Free NHS Foundation Trust
Royal Free Hospital Pond Street
United Kingdom

Sponsor information


Royal Free London NHS Foundation Trust

Sponsor details

Royal Free Hospital
Pond Street
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

NIHR Central Commissioning Facility (CCF); Grant Codes: PB-PG-0817-20013

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Patient and public involvement
An online survey with Kidney Cancer UK (KCUK) involving ninety-nine patients demonstrated their support and need for such a study. The patient representatives helped draft the study protocol, patient information sheets and consent forms. They will represent patient views on the trial management committee, and will have a central role in the design of the full trial and dissemination of study findings.

The protocol is being submitted for publication. The results will be presented at national and international clinical meetings, published in high impact medical journals and communicated to the kidney cancer community through Kidney Cancer UK (KCUK) patient education days, social media and the KCUK and Royal Free Hospital websites.

IPD sharing statement
Anonymised participant level data will be available upon request on a case by case basis, subject to REC approval. Requests can be made to the Chief Investigator. Data will be available not less than 1 year following completion of study and will be available for up to 5 years.

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

2019 protocol in (added 26/06/2020)

Publication citations

Additional files

Editorial Notes

26/06/2020: Publication reference added. 20/05/2020: Recruitment resumed. 17/04/2020: Due to current public health guidance, recruitment for this study has been paused. 22/03/2019: The condition has been changed from “Specialty: Cancer, Primary sub-specialty: Renal Cancer; Health Category: Cancer and neoplasms; Disease/Condition: Malignant neoplasms of urinary tract” to “Kidney cancer” following a request from the NIHR.