The practicing urologist faces an increasingly common dilemma: How should I treat this incidentally discovered small renal mass?
The first question should be: Should I treat this lesion or follow it? We know that the natural history of many of these small tumors is fairly benign, and that as many as one-third are, in fact, benign. Of those that are malignant, the majority grow at a tortoise-like rate and may well not play a role in the race for the patient's life. As the famous tale reminds us, however, sometimes the tortoise wins the race. Thus, until we can accurately predict how an individual lesion will behave, there will be a significant role for active treatment of small renal masses.
How, then, should these masses be treated? It is clear that a nephron-sparing approach should be used whenever possible. With the application of minimally invasive surgical techniques to renal surgery and the evolution of ablative technologies, the urologist has multiple choices. Open or laparoscopic? Robot or not? Resection or ablation? Cook it or freeze it? The approach chosen will depend on the skill set of the surgeon and the technology available.
In it, Dr. Katz and colleagues present data on 82 patients treated with laparoscopic cryoablation and 104 patients treated with laparoscopic partial nephrectomy. Essentially, these two treatment options appeared to have similar impacts on overall quality of life. But while the partial nephrectomy patients appeared to physically function better at 1 and 3 months than their cryoablation counterparts did, they also reported more pain at 3 months.
I agree with Dr. Meng that these differences are not likely clinically significant, and I would argue that quantity of life should be the measuring stick for these treatments. If, in fact, we find that the cancer-specific survival for renal ablative procedures is equivalent to the more mature partial nephrectomy data, then the impact on quality of life may help decide which treatment is most appropriate for the individual patient. Until then, we are left with a long discussion with each patient.
The practitioner must educate the patient on the natural history of a small renal mass, the role of observation, and the many treatment options that are available, as well as the potential impact of each on quality of life. Continued research in the molecular diagnosis of the small renal mass, metabolic imaging, and active treatment modalities such as cryoablation and thermal ablation will no doubt change the details of this "long discussion" over the coming years.
Dr. Strup is the William S. Farish Professor and chief of urology at the University of Kentucky, Lexington.