Safety and efficacy of percutaneous cryoablation in renal cell carcinoma in 2014

Christos Georgiades

The outcomes from our study on the efficacy and safety of percutaneous cryoablation, published recently in CardioVascular and Interventional Radiology, are the result of the most rigorous investigation on the subject to-date. These exceptional numbers (97%, five-year oncologic efficacy and 6% complication rate) however, are a double-edged sword. On one hand, they approach those of the gold standard, on the other, we must prove they are widely reproducible, writes Christos Georgiades

The dynamics of introducing a new treatment for a disease are complex and many times unpredictable. More so, for cancer and especially in the era of multidisciplinary care, advanced technology, burdensome oversight, competing marketing interests and a more educated public. Perhaps it should be this way to avoid introducing procedures/equipment that are not truly beneficial to the patient.

In this complex environment, the option to treat kidney cancer using percutaneous cryoablation was introduced nearly a decade ago. The usual “growing-pains” plagued this option, including lack of prospective studies, lack of long-term outcomes, lack of standardisation of the technique, etc.  The standard of care for kidney cancer is radical or partial nephrectomy, which set a very high efficacy standard. Its five-year oncologic efficacy is reported between 97–100% and any new treatment option must have a comparable result, lest it is limited to a tiny subgroup of patients. Our study confirmed in a rigorous way, (what some previous reports were suggesting) the high efficacy and low complication rate for percutaneous cryoablation. In our prospective study, the long-term efficacy of this option was 97% with a 100% cancer-specific survival at five-year follow-up. This indeed approaches the numbers reported for more invasive options.  What should make percutaneous cryoablation for kidney cancer even more palatable is the low rate of complications, around 6%, the quicker recovery time, and cost-savings.

The high efficacy and low complication rate of percutaneous cryoablation for kidney cancer is not unqualified however. There are factors that are important in achieving and maintaining these results that cannot be quantified or represented scientifically. First, and most important, is the creation of a multidisciplinary team involving the relevant specialties, ie. interventional radiology and urology. We tend to attribute such statements to politics. For those of us who have managed to create such teams and have witnessed the shortcomings of the “go-at-it-alone” mentality, it is an absolutely valid statement. The experiences and capabilities of the two specialties are complementary and they perform better if a “I-have-your-back” relationship exists instead of a competing one. Such an environment encourages learning, communication, minimises risk, and allows for better monitoring and earlier intervention in case of complications. Furthermore, it encourages pushing the limits and allowing for a steeper learning curve, and eventually higher efficacy rates. Equally importantly, the patients easily pick up on such dynamics and feel reassured that they are indeed getting the best care possible.

Of course, cryoablation is not an option for all patients with kidney cancer.  The above reported efficacy and complication rates are limited to stage 1 disease, which refers to tumours up to 7cm in size and confined to the kidney. Thankfully most newly diagnosed patients fall within this stage (nearly 70%). Additionally, the location of the tumour is important and anteriorly located tumours and/or near critical structures (intestine, large blood vessels) have a lower efficacy rate.

What is in the future for percutaneous cryoablation for kidney cancer? As with all new procedures there is a learning curve. The numbers we reported recently, presuppose (in addition to the above) a reasonable operator experience. As a society we need to encourage the training of our younger physicians and provide them with proper oversight, guidance and the wisdom to seek multidisciplinary cooperation. From a societal point of view, if these numbers are achieved only in a few large academic centres, the benefit is only academic.

To summarise, percutaneous cryoablation for stage 1 kidney cancer has been proven to be a great alternative to other more invasive options, but only if certain requirements/selection criteria are met. These are a true spirit of cooperation in a multidisciplinary team; good operator experience and proper patient selection.

Christos Georgiades is with the department of Vascular and Interventional Radiology, American Medical Center, Nicosia, Cyprus. He is also adjunct associate professor of Radiology and Surgery, Vascular and Interventional Radiology, Johns Hopkins University, Baltimore, Maryland, USA