What is the difference between the two operations?
Partial nephrectomy removes only the tumour; radical nephrectomy removes the whole kidney. Both aim at the same thing, complete removal of the cancer, and they differ in what is left behind.
In a partial nephrectomy the artery of the kidney is usually clamped for a short time, the tumour is cut out with a rim of healthy tissue, and the kidney is then stitched closed. The remaining part continues to work. In a radical nephrectomy the artery, vein and ureter are divided and the kidney is taken out together with the fat around it. The adrenal gland is left in place unless imaging suggests it is involved, in line with the European Association of Urology (EAU) guideline.
Partial nephrectomy is the more demanding operation. There is a cut surface that can bleed and a urine-collecting system that can leak, and neither exists after a radical nephrectomy.
What decides between partial and radical nephrectomy?
Three questions decide: can the tumour be removed with a clear margin, how much working kidney would remain, and how much does this patient need it? Tumour size is only one part of the first question.
| Factor | Points towards partial | Points towards radical |
|---|---|---|
| Size and stage | Up to 7 cm, confined to the kidney | Above 7 cm, or growth into fat or a vein |
| Position | Growing outwards, at a pole, away from the main vessels | Central or hilar, deep in the kidney, wrapped around vessels |
| The other kidney | Absent, small or poorly working | Normal |
| Kidney function | Chronic kidney disease or protein in the urine | Normal, with enough reserve after surgery |
| Other illnesses | Diabetes, high blood pressure or other conditions that wear down the kidneys | None that threaten the kidneys |
| Number of tumours | Tumours in both kidneys, several tumours, hereditary kidney cancer | Only when removing them all would leave too little working kidney |
| Age | Younger patients, with more years for kidney disease to matter | Not decisive on its own |
Surgeons describe the anatomy with the R.E.N.A.L. nephrometry score, read from the CT or MRI. It adds points for the size of the tumour, how far it sits inside the kidney, how close it comes to the urine-collecting system and where it lies between the poles, giving a total from 4 to 12. A tumour touching the main artery or vein is marked as hilar. A score of 7 or more is usually treated as moderate or high complexity. This is why the scan images, and not only the written report, are needed to answer the question.
How does tumour size and stage change the answer?
Up to 7 cm, the kidney is kept whenever that is feasible. Above 7 cm, or once the tumour has left the kidney, removal of the whole kidney becomes the usual operation. The table summarises the 2026 EAU guideline and the 2021 American Urological Association (AUA) guideline.
| Situation | Usual recommendation | Source |
|---|---|---|
| T1a: 4 cm or smaller | Partial nephrectomy has priority. Surveillance or ablation for selected patients. | EAU 2026 (strong), AUA 2021 |
| T1b: 4 to 7 cm | Partial nephrectomy when technically feasible, radical nephrectomy when it is not. | EAU 2026 (strong) |
| T2: larger than 7 cm | Usually radical nephrectomy, by a laparoscopic or robotic approach. | EAU 2026 (strong) |
| T2 with a single kidney or chronic kidney disease | Partial nephrectomy if technically feasible. | EAU 2026 (weak) |
| T3 and above: fat or vein involved | Radical nephrectomy, with removal of a tumour thrombus when present. | EAU 2026 |
| Single kidney, tumours in both kidneys, hereditary cancer, kidney disease | Kidney-sparing treatment has priority whenever it is feasible. | AUA 2021 |
Seven centimetres is the staging line between T1 and T2. It is not a technical limit: a 3 cm tumour wrapped around the main vessels can be harder to spare than an 8 cm tumour growing outwards from one pole.
What does the evidence show?
Partial nephrectomy protects kidney function. It has not been proven to make patients live longer. That is the honest summary of the one randomised trial, and it surprises many readers.
EORTC 30904 randomised 541 patients with a tumour of 5 cm or smaller and a normal second kidney to one of the two operations. After a median follow-up of 9.3 years, ten-year overall survival was 81.1% after radical nephrectomy and 75.7% after partial nephrectomy. When the analysis was limited to patients who actually had kidney cancer, the difference was no longer statistically significant. Only 12 of the 117 deaths were caused by kidney cancer, and the cancer progressed in 21 patients: 9 after radical and 12 after partial nephrectomy.
| EORTC 30904 (randomised, 541 patients) | Radical | Partial |
|---|---|---|
| Overall survival at 10 years | 81.1% | 75.7% |
| Cancer progression (patients) | 9 | 12 |
| At least moderately reduced function (eGFR below 60) | 85.7% | 64.7% |
| Advanced kidney disease (eGFR below 30) | 10.0% | 6.3% (difference not significant) |
| Kidney failure (eGFR below 15) | 1.5% | 1.6% |
Limits: the trial closed early because recruitment was slow, so it has less statistical power than planned. The operations were done between 1992 and 2003, mostly by open surgery, before robotic partial nephrectomy existed. Kidney function was followed for a median of 6.7 years.
For larger tumours there is no randomised trial. A meta-analysis of 21 retrospective studies with 11,204 patients (Mir et al., 2017) compared the two operations for tumours above 4 cm. Partial nephrectomy was followed by better kidney function and fewer new cases of chronic kidney disease (relative risk 0.36), at the price of more blood loss and more complications (relative risk 1.74). Recurrence and deaths were also lower after partial nephrectomy, yet those patients were on average younger and had smaller tumours, so this part of the result reflects who was chosen for each operation as much as the operation itself.
What do you gain and what do you accept with a partial nephrectomy?
You gain kidney tissue and accept a somewhat higher surgical risk. For most small tumours that exchange is worth making, and for some it is not.
What you gain
- More working kidney. In EORTC 30904, kidney function fell to a moderately reduced level in 64.7% after partial and 85.7% after radical nephrectomy.
- A reserve for later. If a tumour ever appears in the other kidney, or diabetes or high blood pressure develops, there is more tissue to rely on.
- Similar cancer control for small tumours. Progression was uncommon after both operations in the randomised trial.
What you accept
- More surgical risk. Bleeding and urine leak are specific to partial nephrectomy. For tumours above 4 cm, complications were more frequent than after radical nephrectomy (relative risk 1.74, retrospective data).
- Complex tumours raise the risk further. For tumours deep in the kidney or at the hilum, major complications were more frequent than for simple tumours (odds ratio 1.57) in a meta-analysis of 8,572 patients.
- No proven survival benefit. Better kidney function did not translate into longer life in the randomised trial.
- The plan may change. A partial nephrectomy can become a radical one during the operation.
When is removing the whole kidney the better operation?
When keeping the kidney would make the operation unsafe or the cancer surgery incomplete. A radical nephrectomy is not a failure of treatment. In these situations it is the correct treatment:
- The tumour has grown into the fat around the kidney or into the renal vein or vena cava (stage T3 and above).
- The tumour is larger than 7 cm and the other kidney is healthy.
- The tumour is so central, or so close to the main vessels, that too little working kidney would remain after removal.
- Several tumours occupy the same kidney and removing them all would leave too little working tissue.
- The affected kidney already contributes little to overall function.
The AUA guideline gives a useful rule. Radical nephrectomy is preferred when three conditions are all met: the tumour is highly complex, so that a partial nephrectomy would be difficult even in experienced hands; there is no chronic kidney disease and no protein in the urine; and the other kidney is normal, with an expected kidney function (eGFR) above 45 mL/min/1.73 m² after the operation. If any of the three is missing, partial nephrectomy should be considered.
The plan can also change during surgery. A partial nephrectomy is converted to a radical one if the tumour turns out to extend further than the scan showed, or if bleeding cannot be controlled safely. This possibility is discussed before the operation and is part of the consent.
Does the robot change the decision?
The robot does not change which operation is right. It changes how often a kidney-sparing operation can be done through small incisions. Stitching a kidney closed against the clock is the difficult part of a partial nephrectomy, and wristed instruments with a magnified three-dimensional view help with exactly that step.
In a pooled analysis of 25 retrospective studies with 4,919 patients (Leow et al., 2016), robotic partial nephrectomy was converted to open or radical surgery less often than laparoscopic partial nephrectomy (relative risk 0.36). In the randomised OpeRa trial of 240 patients with moderately or highly complex tumours, robotic surgery gave less pain and a shorter hospital stay than open surgery; complications within 30 days were 37% and 46%, a difference that was not significant, and the trial closed early.
The EAU guideline adds a point that patients rarely hear: for a T1 tumour, a keyhole radical nephrectomy should not be chosen when a partial nephrectomy is feasible by any approach, including open surgery. Keeping the kidney comes before keeping the incisions small.
What does life with one kidney look like?
Most people with one healthy kidney live a normal life, and the remaining kidney takes over part of the lost work. The concern is the long term, and it depends on how healthy that kidney is.
In EORTC 30904, kidney failure (eGFR below 15) was rare and equally frequent after both operations: 1.5% after radical and 1.6% after partial nephrectomy. Moderately reduced function was common in both groups and more common after radical nephrectomy. All patients in that trial started with two normal kidneys. With diabetes, high blood pressure or existing kidney disease the reserve is smaller, which is why the guidelines give these patients priority for kidney-sparing surgery.
After either operation, follow-up includes blood tests for kidney function, a urine test for protein, blood pressure control and imaging at intervals set by the pathology result. Painkillers of the ibuprofen type and contrast agents are used with more care when one kidney remains.
Which questions should you ask your surgeon?
Ask for the reasoning, not only the name of the operation. These questions usually bring it out:
- What is the size and stage of my tumour, and what is its nephrometry score?
- What is my kidney function (eGFR) now, and what do you expect it to be after each operation?
- Is a partial nephrectomy technically feasible in my case? If not, what makes it unsuitable?
- How likely is it that a planned partial nephrectomy becomes a radical one during surgery?
- Would surveillance or ablation be reasonable for a tumour like mine?
If you are reading this from abroad: the CT or MRI images, the radiology report and a recent creatinine or eGFR result are enough for a first assessment before you travel. More on staging, surveillance, ablation and recovery is on the kidney tumours page.
This article gives general information and does not replace an assessment of your own scans and results. Treatment is decided individually.