The increased diagnosis of small renal masses (SRMs) poses the challenge of how best to manage patients with tumours that are not likely to progress and cause death during their lifetime. Concerns regarding overdiagnosis and overtreatment of patients with low-risk or indolent disease has led to the introduction of active surveillance as an alternative to immediate intervention in select candidates. However, differentiating between benign or low-grade lesions and high-grade aggressive phenotypes is difficult. Renal biopsy, radiographic assessment, and clinical nomograms have been used before surgery to evaluate the probability of whether an SRM will exhibit characteristics of an aggressive cancer. SRM growth trends have been studied over periods of observation but no characteristics have been found to correlate with aggressive growth kinetics. Stratification of patients with SRMs according to risk status is crucial when considering whether active surveillance might be an appropriate treatment option. Factors that should be taken into account include comorbidities, a history of malignancy, pre-existing chronic kidney disease, life expectancy and patient preference. Standardized active surveillance protocols are currently lacking, and clinical trials designed to randomize patients with SRMs to receive either active surveillance or immediate treatment are sorely needed to address the existing evidence gap.
Early detection of small renal masses (SRMs) has not changed the mortality rate of renal cell carcinoma, leading to concerns of overdiagnosis and overtreatment
Active surveillance with curative intent might be an appropriate alternative to immediate intervention for patients with low-risk or indolent disease
Differentiating between benign or low-grade lesions and high-grade aggressive phenotypes is challenging. Renal biopsy, radiographic assessment, and clinical nomograms have been used before surgery to evaluate malignant potential
SRM growth trends have been studied in patients over periods of observation but no characteristics have been found to correlate with aggressive growth kinetics
To date, all lesions that have progressed to metastases while under an initial period of observation have been >3 cm and have demonstrated positive growth rates over time
Stratification of patients with SRMs to identify those who might be suitable candidates for active surveillance should take into account comorbidities, a history of malignancy, pre-existing chronic kidney disease, life expectancy and patient preference
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Siegel, R., Naishadham, D. & Jemal, A. Cancer statistics, 2012. CA Cancer J. Clin. 62, 10–29 (2012).
Chow, W. H. et al. Rising incidence of renal cell cancer in the United States. JAMA 281, 1628–1631 (1999).
Hollingsworth, J. M. et al. Rising incidence of small renal masses: a need to reassess treatment effect. J. Natl Cancer Inst. 98, 1331–1334 (2006).
Kane, C. J. et al. Renal cell cancer stage migration: analysis of the National Cancer Data Base. Cancer 113, 78–83 (2008).
Cooperberg, M. R. et al. Decreasing size at diagnosis of stage 1 renal cell carcinoma: analysis from the National Cancer Data Base, 1993 to 2004. J. Urol. 179, 2131–2135 (2008).
Jayson, M. & Sanders, H. Increased incidence of serendipitously discovered renal cell carcinoma. Urology 51, 203–205 (1998).
Kutikov, A. et al. Incidence of benign pathologic findings at partial nephrectomy for solitary renal mass presumed to be renal cell carcinoma on preoperative imaging. Urology 68, 737–740 (2006).
Crispen, P. L. et al. Outcomes following partial nephrectomy by tumor size. J. Urol. 180, 1912–1917 (2008).
Remzi, M. et al. Are small renal tumors harmless? Analysis of histopathological features according to tumors 4 cm or less in diameter. J. Urol. 176, 896–899 (2006).
Hollenbeck, B. K. et al. National utilization trends of partial nephrectomy for renal cell carcinoma: a case of underutilization? Urology 67, 254–259 (2006).
Campbell, S. C. et al. Guideline for management of the clinical T1 renal mass. J. Urol. 182, 1271–1279 (2009).
Huang, W. C. et al. Chronic kidney disease after nephrectomy in patients with renal cortical tumours: a retrospective cohort study. Lancet Oncol. 7, 735–740 (2006).
McKiernan, J. et al. Natural history of chronic renal insufficiency after partial and radical nephrectomy. Urology 59, 816–820 (2002).
Go, A. S. et al. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N. Engl. J. Med. 351, 1296–1305 (2004).
Huang, W. C. et al. Partial nephrectomy versus radical nephrectomy in patients with small renal tumors--is there a difference in mortality and cardiovascular outcomes? J. Urol. 181, 55–61 (2009).
Miller, D. C. et al. Renal and cardiovascular morbidity after partial or radical nephrectomy. Cancer 112, 511–520 (2008).
Sun, M. et al. A non-cancer-related survival benefit is associated with partial nephrectomy. Eur. Urol. 61, 725–731 (2011).
Thompson, R. H. et al. Radical nephrectomy for pT1a renal masses may be associated with decreased overall survival compared with partial nephrectomy. J. Urol. 179, 468–471 (2008).
Weight, C. J. et al. Partial nephrectomy is associated with improved overall survival compared to radical nephrectomy in patients with unanticipated benign renal tumours. Eur. Urol. 58, 293–298 (2010).
Zini, L. et al. Radical versus partial nephrectomy: effect on overall and noncancer mortality. Cancer 115, 1465–1471 (2009).
Tan, H. J. et al. Long-term survival following partial vs radical nephrectomy among older patients with early-stage kidney cancer. JAMA 307, 1629–1635 (2012).
Ljungberg, B. et al. EAU guidelines on renal cell carcinoma: the update. Eur. Urol. 58, 398–406 (2010).
Smaldone, M. C. et al. Does partial nephrectomy result in a durable overall survival benefit in the medicare population? J. Urol. 188, 2089–2094 (2012).
Van Poppel, H. et al. A prospective, randomised EORTC intergroup phase 3 study comparing the oncologic outcome of elective nephron-sparing surgery and radical nephrectomy for low-stage renal cell carcinoma. Eur. Urol. 59, 543–552 (2011).
Kim, S. P. et al. Contemporary trends in nephrectomy for renal cell carcinoma in the United States: results from a population based cohort. J. Urol. 186, 1779–1785 (2011).
Filson, C. P. et al. Surgeon characteristics and long-term trends in the adoption of laparoscopic radical nephrectomy. J. Urol. 185, 2072–2077 (2011).
Smaldone, M. C. et al. Assessing performance trends in laparoscopic nephrectomy and nephron-sparing surgery for localized renal tumors. Urology 80, 286–291 (2012).
Dulabon, L. M. et al. Trends in renal tumor surgery delivery within the United States. Cancer 116, 2316–2321 (2010).
Gill, I. S. et al. Comparison of 1,800 laparoscopic and open partial nephrectomies for single renal tumors. J. Urol. 178, 41–46 (2007).
Scoll, B. J. et al. Robot-assisted partial nephrectomy: a large single-institutional experience. Urology 75, 1328–1334 (2010).
Kutikov, A., Kunkle, D. A. & Uzzo, R. G. Focal therapy for kidney cancer: a systematic review. Curr. Opin. Urol. 19, 148–153 (2009).
Welch, H. G. & Black, W. C. Overdiagnosis in cancer. J. Natl Cancer Inst. 102, 605–613 (2010).
Chou, R. et al. Screening for prostate cancer: a review of the evidence for the US Preventive Services Task Force. Ann. Intern. Med. 155, 762–771 (2011).
Wilt, T. J. et al. The Prostate cancer Intervention Versus Observation Trial: VA/NCI/AHRQ Cooperative Studies Program #407 (PIVOT): design and baseline results of a randomized controlled trial comparing radical prostatectomy to watchful waiting for men with clinically localized prostate cancer. Contemp. Clin. Trials 30, 81–87 (2009).
Uzzo, R. G. Renal masses--to treat or not to treat? If that is the question are contemporary biomarkers the answer? J. Urol. 180, 433–434 (2008).
Lane, B. R. et al. Renal mass biopsy—a renaissance? J. Urol. 179, 20–27 (2008).
Wang, R. et al. Accuracy of percutaneous core biopsy in management of small renal masses. Urology 73, 586–590 (2009).
Lechevallier, E. et al. Fine-needle percutaneous biopsy of renal masses with helical CT guidance. Radiology 216, 506–510 (2000).
Blumenfeld, A. J. et al. Percutaneous biopsy of renal cell carcinoma underestimates nuclear grade. Urology 76, 610–613 (2010).
Leveridge, M. J. et al. Outcomes of small renal mass needle core biopsy, nondiagnostic percutaneous biopsy, and the role of repeat biopsy. Eur. Urol. 60, 578–584 (2011).
Mason, R. J. et al. Growth kinetics of renal masses: analysis of a prospective cohort of patients undergoing active surveillance. Eur. Urol. 59, 863–867 (2011).
Rothman, J. et al. Pathologic concordance of sporadic synchronous bilateral renal masses. Urology 72, 138–142 (2008).
Pal, S. K. et al. Breaking through a plateau in renal cell carcinoma therapeutics: development and incorporation of biomarkers. Mol. Cancer Ther. 9, 3115–3125 (2010).
Frank, I. et al. Solid renal tumors: an analysis of pathological features related to tumor size. J. Urol. 170, 2217–2220 (2003).
Thompson, R. H. et al. Tumor size is associated with malignant potential in renal cell carcinoma cases. J. Urol. 181, 2033–2036 (2009).
Rothman, J. et al. Histopathological characteristics of localized renal cell carcinoma correlate with tumor size: a SEER analysis. J. Urol. 181, 29–33 (2009).
Kunkle, D. A. et al. Tumor size predicts synchronous metastatic renal cell carcinoma: implications for surveillance of small renal masses. J. Urol. 177, 1692–1696 (2007).
Nguyen, M. M. & Gill, I. S. Effect of renal cancer size on the prevalence of metastasis at diagnosis and mortality. J. Urol. 181, 1020–1027 (2009).
Thompson, R. H. et al. Metastatic renal cell carcinoma risk according to tumor size. J. Urol. 182, 41–45 (2009).
Duffey, B. G. et al. The relationship between renal tumor size and metastases in patients with von Hippel-Lindau disease. J. Urol. 172, 63–65 (2004).
Schachter, L. R. et al. The impact of tumour location on the histological subtype of renal cortical tumours. BJU Int. 98, 63–66 (2006).
Venkatesh, R. et al. Laparoscopic partial nephrectomy for renal masses: effect of tumor location. Urology 67, 1169–1174 (2006).
Kutikov, A. & Uzzo, R. G. The R. E. N. A. L. nephrometry score: a comprehensive standardized system for quantitating renal tumor size, location and depth. J. Urol. 182, 844–853 (2009).
Kutikov, A. et al. Anatomic features of enhancing renal masses predict malignant and high-grade pathology: a preoperative nomogram using the RENAL Nephrometry score. Eur. Urol. 60, 241–248 (2011).
Lawrentschuk, N. et al. Functional imaging of renal cell carcinoma. Nat. Rev. Urol. 7, 258–266 (2010).
Lawrentschuk, N. et al. Positron emission tomography (PET), immuno-PET and radioimmunotherapy in renal cell carcinoma: a developing diagnostic and therapeutic relationship. BJU Int. 97, 916–922 (2006).
Divgi, C. R. et al. Preoperative characterisation of clear-cell renal carcinoma using iodine-124-labelled antibody chimeric G250 (124I-cG250) and PET in patients with renal masses: a phase I trial. Lancet Oncol. 8, 304–310 (2007).
Divgi, C. R. et al. Positron emission tomography/computed tomography identification of clear cell renal cell carcinoma: results from the REDECT trial. J. Clin. Oncol. 31, 187–194 (2013).
Lane, B. R. et al. Active treatment of localized renal tumors may not impact overall survival in patients aged 75 years or older. Cancer 116, 3119–3126 (2010).
Santos Arrontes, D. et al. Survival analysis of clear cell renal carcinoma according to the Charlson comorbidity index. J. Urol. 179, 857–861 (2008).
Hollingsworth, J. M. et al. Five-year survival after surgical treatment for kidney cancer: a population-based competing risk analysis. Cancer 109, 1763–1768 (2007).
Kutikov, A. et al. Evaluating overall survival and competing risks of death in patients with localized renal cell carcinoma using a comprehensive nomogram. J. Clin. Oncol. 28, 311–317 (2010).
Lughezzani, G. et al. Population-based external validation of a competing-risks nomogram for patients with localized renal cell carcinoma. J. Clin. Oncol. 28, e299–e300 (2010).
Kutikov, A. et al. Competing risks of death in patients with localized renal cell carcinoma: a comorbidity based model. J. Urol. 188, 2077–2083 (2012).
Jeldres, C. et al. Can renal mass biopsy assessment of tumor grade be safely substituted for by a predictive model? J. Urol. 182, 2585–2589 (2009).
Lane, B. R. et al. A preoperative prognostic nomogram for solid enhancing renal tumors 7 cm or less amenable to partial nephrectomy. J. Urol. 178, 429–434 (2007).
Wang, H. K. et al. External validation of a nomogram using RENAL nephrometry score to predict high grade renal cell carcinoma. J. Urol. 187, 1555–1560 (2012).
Smaldone, M. C. et al. Small renal masses progressing to metastases under active surveillance: a systematic review and pooled analysis. Cancer 118, 997–1006 (2012).
Jewett, M. A. et al. Active surveillance of small renal masses: progression patterns of early stage kidney cancer. Eur. Urol. 60, 39–44 (2011).
Volpe, A. et al. The natural history of incidentally detected small renal masses. Cancer 100, 738–745 (2004).
Ozono, S. et al. Tumor doubling time of renal cell carcinoma measured by CT: collaboration of Japanese Society of Renal Cancer. Jpn J. Clin. Oncol. 34, 82–85 (2004).
Crispen, P. L. et al. Natural history, growth kinetics, and outcomes of untreated clinically localized renal tumors under active surveillance. Cancer 115, 2844–2852 (2009).
Chawla, S. N. et al. The natural history of observed enhancing renal masses: meta-analysis and review of the world literature. J. Urol. 175, 425–431 (2006).
Haramis, G. et al. Natural history of renal cortical neoplasms during active surveillance with follow-up longer than 5 years. Urology 77, 787–791 (2011).
Mues, A. C. et al. Active surveillance for larger (cT1bN0M0 and cT2N0M0) renal cortical neoplasms. Urology 76, 620–623 (2010).
Siu, W. et al. Growth rates of renal cell carcinoma and oncocytoma under surveillance are similar. Urol. Oncol. 25, 115–119 (2007).
Neuzillet, Y. et al. Follow-up of renal oncocytoma diagnosed by percutaneous tumor biopsy. Urology 66, 1181–1185 (2005).
Kunkle, D. A. et al. Enhancing renal masses with zero net growth during active surveillance. J. Urol. 177, 849–853 (2007).
Bosniak, M. A. et al. Small renal parenchymal neoplasms: further observations on growth. Radiology 197, 589–597 (1995).
Wehle, M. J. et al. Conservative management of incidental contrast-enhancing renal masses as safe alternative to invasive therapy. Urology 64, 49–52 (2004).
Dall'Era, M. A. et al. Active surveillance for early-stage prostate cancer: review of the current literature. Cancer 112, 1650–1659 (2008).
Crispen, P. L. et al. Delayed intervention of sporadic renal masses undergoing active surveillance. Cancer 112, 1051–1057 (2008).
Abouassaly, R. et al. What is the best treatment strategy for incidentally detected small renal masses? A decision analysis. BJU Int. 108, E223–E231 (2011).
Crispen, P. L. & Uzzo, R. G. The natural history of untreated renal masses. BJU Int. 99, 1203–1207 (2007).
Fujimoto, H. et al. Intraductal tumor involvement and renal parenchymal invasion of transitional cell carcinoma in the renal pelvis. J. Urol. 153, 57–60 (1995).
Oda, T. et al. Growth rates of primary and metastatic lesions of renal cell carcinoma. Int. J. Urol. 8, 473–477 (2001).
Kato, M. et al. Natural history of small renal cell carcinoma: evaluation of growth rate, histological grade, cell proliferation and apoptosis. J. Urol. 172, 863–866 (2004).
Sowery, R. D. & Siemens, D. R. Growth characteristics of renal cortical tumors in patients managed by watchful waiting. Can. J. Urol. 11, 2407–2410 (2004).
Lamb, G. W. et al. Management of renal masses in patients medically unsuitable for nephrectomy--natural history, complications, and outcome. Urology 64, 909–913 (2004).
Kouba, E. et al. Watchful waiting for solid renal masses: insight into the natural history and results of delayed intervention. J. Urol. 177, 466–470 (2007).
Abou Youssif, T. et al. Active surveillance for selected patients with renal masses: updated results with long-term follow-up. Cancer 110, 1010–1014 (2007).
Fernando, H. S., Duvuru, S. & Hawkyard, S. J. Conservative management of renal masses in the elderly: our experience. Int. Urol. Nephrol. 39, 203–207 (2007).
Matsuzaki, M. et al. Conservative management of small renal tumors. Hinyokika Kiyo 53, 207–211 (2007).
Abouassaly, R., Lane, B. R. & Novick, A. C. Active surveillance of renal masses in elderly patients. J. Urol. 180, 505–508 (2008).
Beisland, C. et al. Observation should be considered as an alternative in management of renal masses in older and comorbid patients. Eur. Urol. 55, 1419–1427 (2009).
Rosales, J. C. et al. Active surveillance for renal cortical neoplasms. J. Urol. 183, 1698–1702 (2010).
Hwang, C. K. et al. Estimated volume growth characteristics of renal tumors undergoing active surveillance. Can. J. Urol. 17, 5459–5464 (2010).
Li, X. S. et al. Growth pattern of renal cell carcinoma (RCC) in patients with delayed surgical intervention. J. Cancer Res. Clin. Oncol. 138, 269–274 (2012).
R. G. Uzzo declares he has acted as a consultant for Wilex AG. The other authors declare no competing interests.
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Smaldone, M., Corcoran, A. & Uzzo, R. Active surveillance of small renal masses. Nat Rev Urol 10, 266–274 (2013). https://doi.org/10.1038/nrurol.2013.62
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