Cryotherapy for kidney cancer: is the treatment effective?

Cryotherapy is a procedure that destroys tissues in the body by freezing them to an extremely low temperature. Consultant urologist Mr Christopher Anderson performed the first laparoscopic cases in the UK to treat early-stage kidney cancer. Here he explains what to expect after treatment and just how effective the procedure is.
 

What can I expect after cryotherapy?

Most patients go home the following day. Sometimes patient recovery can be slower and is influenced by their overall fitness.

Complication rates are low, but one of the worst might be that the patient has bled around the kidney post-operatively, which might require intervention.

A CT scan is performed at three months, six months and 12 months in the first year and thereafter every six for five years. In the event of tumour recurrence, one would have to re-evaluate the best form of management.

This might involve a repeat of the same procedure or alternatively a larger undertaking with either partial or total removal of the entire kidney. Performing surgery after cryotherapy is difficult due to the presence of the scar tissue.
 

Is the treatment effective?

There have been numerous studies that have shown the efficacy of this method. A large laparoscopic study described the outcomes of 150 patients, of which 56 had more than three-year follow up. There was 75% shrinkage of tumour size seen at three years and of the entire series, there were two patients who had a recurrence of the tumour. The results were best in those patients who have an isolated renal tumour (commonly called sporadic) in one kidney: here there was a 98% survival rate from renal cancer at three years.

In patients who had tumours in both kidneys, the results showed a three-year survival of 89%. The reason for this is the fact that the tumour treated with cryotherapy was in some cases obviously being done on a metastasis (spread) rather than a primary tumour. (1)

In a study of 220 biopsy-proven RCC, the local recurrence rate and metastasis-free survival was 97.2% and 97.7% at three years and 93.9% and 94.4% at five years. The major complication rate was 4.9%. They concluded five-year oncological outcomes are competitive with those of surgical resection and at lower complication rate. (2)

A meta-analysis of 3900 patients reached similar conclusions and stated that thermal ablation showed no significant difference in local recurrence or metastases compared with partial nephrectomy. There was lower morbidity and a lesser reduction in eGFR, but with higher all cause mortality and cancer-specific mortality. (3)

In one study, among 104 patients treated percutaneously assessed with a mean radiological follow-up of 20.1 months, a single case of unexpected late local recurrence was found. However, there were only 62 patients with biopsy-proven RCC, which is a very common critique of most studies. (4)

Based on a meta-analysis, when ablating renal tumours, a percutaneous approach was safer than an open or laparoscopic approach and was equally effective. However, more than one procedure was needed to treat the tumour completely. (5)

Generally, of the probe-ablative therapies currently available for renal tumours, cryotherapy is the most studied and clinically applied treatment. Relatively short-term results are very encouraging but long-term data is needed to compare cancer control with total or partial removal of the kidney. Patients have to be carefully selected: those with small, peripheral, renal lesions are best suited.
 

Are there limitations?

One of the main problems is that cryotherapy (and all other ablative treatments like RFA and HIFU) does not generate pathological specimens for the pathologist to study and stage cancer accurately. Before the procedure, a biopsy is taken but this only confirms whether the tumour is cancer and gives very little information about the tumour itself. This is in contrast to a partial nephrectomy where the tumour alone or, in total nephrectomy, where the whole kidney is given to the pathologist for analysis.

Another critique is that we have to rely on CT or MRI scans to determine whether there is a good response to cryotherapy and also whether there is any recurrence of tumour subsequently. This requires a long term meticulous follow up. Patients need to be prepared for and committed to this.

Most studies only have relatively short term follow up. This is particularly relevant in small renal masses as they grow very slowly and oncological outcomes are likely to be good in the short term for almost any treatment approach adopted. Long-term data is needed to determine the real oncological results of cryotherapy.

Furthermore, oncological outcomes from previous percutaneous ablation studies are difficult to interpret because of the large number of patients treated previously for RCC as well as a large number of treated renal masses without a pathology-proven diagnosis (6)

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References

1. Gill I S, Remer EM, Hassan WA et al. Renal Cryoablation: outcome at 3 years. J Urol 2005173:1903-7.

2. David J. Breen, FRCR • Alexander J. King, FRCR • Nirav Patel, FRCR • Richard Lockyer, FRCS •Matthew Hayes, FRCS. Radiology 2018; nn:1–81 • https://doi.org/10.1148/radiol.2018180249

3. J. Ricardo Rivero, MDa, Jose De La Cerda III, MD, MPHa, Hanzhang Wang, MD, MPHa, Michael A. Liss, MDa,b, Ann M. Farrell, MLSd, Ronald Rodriguez, MD, PhDa,b, Rajeev Suri, MDc, Dharam Kaushik, MD. Partial Nephrectomy versus Thermal Ablation for Clinical Stage T1 Renal Masses: Systematic Review and Meta-Analysis of More than 3,900 Patients. J Vasc Interv Radiol 2017; ▪:1–12 https://doi.org/10.1016/j.jvir.2017.08.013

4. David J. Breen, Timothy J. Bryant, Ausami Abbas, Beth Shepherd, Neil McGill, Jane A. Anderson†, Richard C. Lockyer, Matthew C. Hayes and Steve L. George. Percutaneous cryoablation of renal tumours: outcomes from 171 tumours in 147 patients. Onlinelibrary.wiley.com/doi/10.1111/bju12122

5. Hui GC1, Tuncali K, Tatli S, Morrison PR, Silverman SG. Comparison of percutaneous and surgical approaches to renal tumor ablation: metaanalysis of effectiveness and complication rates. J Vasc Interv Radiol. 2008 Sep;19(9):1311-20. doi: 10.1016/j.jvir.2008.05.014. Epub 2008 Jul 21.

6. Grant D. Schmit , R. Houston Thompson * , Anil N. Kurup , Adam J. Weisbrod ,Rickey E. Carter † , Matthew R. Callstrom and Thomas D. Atwell. Percutaneous cryoablation of solitary sporadic renal cell carcinomas. Onlinelibrary.wiley.com/doi/10.1111/j.1464-410X.2012.x/pdf