The landscape of renal cell carcinoma (RCC) has changed substantially with the advent of modern imaging. Historically, many renal tumors were diagnosed after symptoms such as hematuria, flank pain, or a palpable mass. Today, however, more than half of RCCs are detected incidentally during imaging for unrelated conditions.1
This shift reflects real progress in diagnostic capacity. Still, it raises an important clinical question: are we detecting more life-threatening cancers, or are we increasingly identifying tumors that may never have become clinically relevant during a patient’s lifetime? This question was the central motivation for our review.
The Incidence–Mortality Paradox
One of the most striking observations in kidney cancer epidemiology is the divergence between incidence and mortality. RCC incidence has risen substantially in recent decades, while mortality has remained relatively stable.2 Although earlier diagnosis, stage migration, and therapeutic advances likely contribute to this pattern, overdiagnosis offers an additional explanation.
Overdiagnosis does not mean an incorrect diagnosis. Rather, it refers to the detection of a true tumor that would not have caused symptoms or death if it had remained undiscovered.3,4 This distinction is particularly relevant in RCC, where many newly detected lesions are small renal masses (SRMs). Surgical series suggest that approximately 20–30% of SRMs are benign, and many malignant lesions exhibit indolent biological behavior.5
When Detection Becomes Overdiagnosis
The success of modern imaging has created a new challenge: distinguishing tumors that require treatment from those that do not. Incidental detection may prompt additional imaging, biopsy, surveillance, and sometimes surgery. For some patients, this pathway enables timely curative treatment. For others, it may lead to intervention for tumors unlikely to affect survival.
The consequences are not trivial. Surgical treatment can expose patients to perioperative risks and loss of renal function, particularly when intervention is performed for biologically indolent disease.6 Furthermore, the psychological impact of receiving a cancer diagnosis should not be underestimated. Even when a lesion carries a low risk of progression, the label of “cancer” often generates substantial anxiety and may influence decisions toward intervention.4
Recognizing overdiagnosis is therefore not an argument against imaging or early detection. Rather, it is a call for more precise interpretation of what imaging reveals.
Active Surveillance as Part of the Solution
Active surveillance has become an important strategy for selected patients with SRMs. Evidence from pooled analyses and prospective cohorts shows excellent cancer-specific outcomes, with metastatic progression occurring in fewer than 2% of carefully monitored patients during follow-up.7,8
These data challenge the historical assumption that every renal mass requires immediate treatment. Instead, management should consider tumor size, growth kinetics, patient age, comorbidities, life expectancy, and competing risks. Active surveillance should not be viewed as inaction but as a structured approach that avoids unnecessary treatment while preserving oncologic safety.
Looking Forward
The central message of our review is that overdiagnosis is an unintended consequence of diagnostic progress. Modern imaging has transformed RCC from a predominantly symptomatic disease to one frequently detected incidentally, revealing tumors with widely variable biological potential.
The challenge moving forward is not simply to detect more renal tumors but to identify which tumors truly matter. Emerging approaches, including radiomics, artificial intelligence, molecular profiling, and improved risk stratification, may help refine this distinction. Ultimately, the goal is not fewer diagnoses but more meaningful diagnoses: identifying the right tumor in the right patient at the right time.
Katherine Vallecilla, MD1,2 and Herney Andres Garcia-Perdomo, MD, MSc, EdD, PhD, FACS1,2
- UROGIV Research Group. School of Medicine. Universidad del Valle. Cali, Colombia.
- Division of Urology/Urooncology. Department of Surgery. School of Medicine. Universidad del Valle. Cali, Colombia.
- Gray RE, Harris GT. Renal cell carcinoma: diagnosis and management. Am Fam Physician. 2019;99:179–184.
- Chow WH, Devesa SS, Warren JL, Fraumeni JF. Rising incidence of renal cell cancer in the United States. JAMA. 1999;281:1628–1631.
- Welch HG, Black WC. Overdiagnosis in cancer. J Natl Cancer Inst. 2010;102:605–613.
- Esserman LJ, Thompson IM, Reid B. Overdiagnosis and overtreatment in cancer: an opportunity for improvement. JAMA. 2013;310:797–798.
- Motzer RJ, Jonasch E, Michaelson MD, et al. Featured updates to the NCCN Guidelines. J Natl Compr Canc Netw. 2019;17:1278–1285.
- Huang WC, Levey AS, Serio AM, et al. Chronic kidney disease after nephrectomy in patients with renal cortical tumors. Lancet Oncol. 2006;7:735–740.
- Smaldone MC, Kutikov A, Egleston BL, et al. Small renal masses progressing to metastases under active surveillance: a systematic review and pooled analysis. Cancer. 2012;118:997–1006.
- Pierorazio PM, Johnson MH, Ball MW, et al. Five-year analysis of a multi-institutional prospective clinical trial of delayed intervention and surveillance for small renal masses: The DISSRM Registry. Eur Urol. 2015;68:408–415.