Original study
Small Renal Masses Initially Managed Using Active Surveillance: Results From a Retrospective Study With Long-Term Follow-Up

https://doi.org/10.1016/j.clgc.2013.11.011Get rights and content

Abstract

Background

The purpose of this study was to provide outcomes of patients managed using active surveillance (AS) for small renal masses (SRMs).

Patients and Methods

We retrospectively reviewed data of 62 patients diagnosed with 64 contrast enhancing SRMs suspicious for renal cell carcinoma. We evaluated the differences between patients who remained on AS and those who underwent delayed surgical intervention.

Results

The mean age of patients was 75 years and the mean follow-up was 91.5 months. The median tumor size and the median estimated tumor volume were 2.6 cm and 8.7 cm3, respectively. The median linear growth rate and the median volumetric growth rate were 0.7 cm/y and 8.8 cm3/y, respectively. The mean linear and volumetric growth rates of the group of patients who underwent surgery was higher than in those who remained on surveillance (1.9 vs. 0.4 cm/y and 16.1 vs. 4.6 cm3/y, respectively; P < .001).

Conclusion

Most SRMs show an indolent course, with low metastatic potential. Faster linear and volumetric growth rates could be the expression of malignant disease, thus suggesting the need for a delayed surgical intervention. AS is a reasonable option for the management of SRMs in properly selected patients with low life expectancy.

Introduction

The widespread and increasing use of noninvasive abdominal imaging (computed tomography [CT], magnetic resonance imaging [MRI], and ultrasonography) has led to a significant growing number of incidentally detected small renal masses (SRMs).1, 2 Most of these are ≤ 4 cm in dimension, and in several cases are diagnosed in elderly and comorbid patients.3 Therefore, renal cell carcinoma (RCC) has been going through a stage and size migration.4 Traditionally, radical nephrectomy (RN) was mostly adopted for surgical treatment of renal cancer, regardless of the tumor size; more recently, nephron-sparing surgery, performed using traditional open, laparoscopic, or robotic approaches, has been considered the current standard of care for clinically localized RCC whenever technically feasible,5 with promising oncological results,6 and lower renal function impairment7 when compared with RN, and low rate of positive surgical margins,8 even in the most challenging and complex procedures.9, 10 Recent surgical series indicate that 20% to 30% of SRMs are benign at final histology, showing low metastatic potential,3 even if 20% to 25% of those renal masses have potentially aggressive behavior.11 Most of these masses will grow slowly, with low risk of distant metastases (1%-3%), as reported by several retrospective and prospective studies.12, 13, 14 The management of SRMs, especially in elderly and comorbid patients, represents a controversial issue for the urologist; thermal ablations (cryotherapy and radiofrequency ablation) and active surveillance (AS) are valid treatment strategies in selected patients who are not optimal surgical candidates.15 Moreover, in patients initially managed with AS, the radiographic linear and volumetric growth pattern seems to be a useful indicator for aggressive behavior of SRM, thus suggesting the need for an active treatment of the tumor.14 In this retrospective study we provide our experience with AS after a long-term follow-up, and we report the oncological outcomes of patients in AS compared with those who underwent delayed surgical intervention.

Section snippets

Patients and Methods

We retrospectively reviewed our prospectively collected database of 58 patients diagnosed with 60 contrast enhancing SRMs suspicious for RCC, detected during imaging procedures between January 1996 and May 2013. Indications for an AS management were: relevant comorbidities, advanced age, or patient refusal of surgery. Patients with Von Hippel-Lindau syndrome, history of hereditary RCC, and metastatic disease at presentation were not included in the cohort. Our follow-up protocol has been

Results

The clinical, demographic, and tumor characteristics are listed in Table 1. The mean and the median patient age were 75 and 77 years, respectively (range, 65-90 years); of the entire cohort of patients, 42 were male (67.7%). The mean follow-up duration was 91.5 months (range, 8-208 months). Most of the SRMs (93.7%) were incidentally diagnosed during imaging procedures performed for other reasons; the other cases were diagnosed in patients who complained of abdominal or back pain. The mean

Discussion

In our study we reported the outcomes after long-term AS for SRMs in a selected cohort of patients. Interestingly, the mean linear and volumetric growth rates were significantly higher in patients who underwent delayed surgical intervention, and most (14/16; 87.5%) of the treated SRMs were malignant at the definitive pathological examination, thus suggesting a more aggressive biological behavior of the malignant lesions. Unfortunately, the current imaging techniques alone are unable to

Conclusions

Most of the SRMs will grow slowly, and demonstrate a low metastatic potential. Malignant behavior and disease progression could be predicted by fast linear and volumetric growth rates, thus suggesting the need for delayed surgical intervention. In properly selected patients, especially those with short life expectancy and with high operative risk, AS could be a reasonable option in the management of SRMs.

Other prospective studies with long follow-up and larger cohort of patients are needed to

Disclosure

The authors have stated that they have no conflicts of interest.

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