Contemporary management of small renal tumors

The incidence of kidney cancer in the United States is rising because the increased use of cross-sectional imaging is resulting in more tumors being detected and because the population is aging. In addition, a stage migration in kidney cancer has been observed—again because of improved detection—with an increase in stage T1 tumors and a concomitant decrease in the number of stage T2 to T4 tumors. Recent studies have shown that up to 80% of small renal tumors (SRTs) either have an indolent course or are histologically benign. These fndings raise the question of what the optimal management of SRTs should be. Radical nephrectomy, the traditional, most aggressive, and still most frequently used extirpative surgery, has been shown to increase the risk of chronic kidney disease. Therefore, during the past 2 decades there has been a shift toward nephron-sparing surgery in carefully selected patients as such procedures have demonstrated equivalent oncologic outcomes with a decrease in long-term renal-induced morbidities. More recently, thermal ablative techniques have evolved as a reliable minimally invasive option for SRTs that can provide adequate oncologic control with minimal morbidity. Finally, in patients with limited life expectancies, active surveillance may be a reasonable approach given the slow median growth rate of SRTs. In evaluating patients with SRTs, percutaneous renal biopsies are being used safely and with increasing accuracy, providing valuable histologic information that can be used to guide the management of SRTs. This article will explore the approaches to managing and treating this growing cohort of patients with SRTs, which are usually incidentally identifed.