Active Surveillance for Small Renal Masses: When Less is More

Small Renal Masses without Gross Fat: What Is the Role of Contrast-Enhanced MDCT?

Increased detection of small renal masses (SRMs) has encouraged research for non-invasive diagnostic tools capable of adequately differentiating malignant vs. benign SRMs and the type of the tumour. Multi-detector computed tomography (MDCT) has been suggested as an alternative to intervention, therefore, it is important to determine both the capabilities and limitations of MDCT for SRM evaluation. In our study, two abdominal radiologists retrospectively blindly assessed MDCT scan images of 98 patients with incidentally detected lipid-poor SRMs that did not present as definitely aggressive lesions on CT. Radiological conclusions were compared to histopathological findings of materials obtained during surgery that were assumed as the gold standard. The probability (odds ratio (OR)) in regression analyses, sensitivity (SE), and specificity (SP) of predetermined SRM characteristics were calculated. Correct differentiation between malignant vs. benign SRMs was detected in 70.4% of cases, with more accurate identification of malignant (73%) in comparison to benign (65.7%) lesions. The radiological conclusions of SRM type matched histopathological findings in 56.1%. Central scarring (OR 10.6, p = 0.001), diameter of lesion (OR 2.4, p = 0.003), and homogeneous accumulation of contrast medium (OR 3.4, p = 0.03) significantly influenced the accuracy of malignant diagnosis. SE and SP of these parameters varied from 20.6% to 91.3% and 22.9% to 74.3%, respectively. In conclusion, MDCT is able to correctly differentiate malignant versus uncharacteristic benign SRMs in more than 2/3 of cases. However, frequency of the correct histopathological SRM type MDCT identification remains low.

Contemporary standards in UK nephrectomy practice: Analysis of the British Association of Urological Surgeons Complex Operations Reports, 2016–2018

Objective:

To analyse the 2016–2018 British Association of Urological Surgeons (BAUS) Complex Operations Reports nephrectomy database, providing a comprehensive description of modern nephrectomy practice.

Patients and Methods:

Analysis of 2016–2018 data held on the BAUS Complex Operations Reports nephrectomy database was performed for 21,366 patients in England. Data are reported on patient, disease, operation and outcome variables.

Results:

Using Hospital Episode Statistics (HES) as a comparator, the database captured an estimated 88% of nephrectomies. Benign nephrectomies (BNs) accounted for 11%, 51% were radical nephrectomies (RNs), 14% were nephroureterectomies (NUs) and 22% were partial nephrectomies (PNs). Of the 2399 BNs, 10% were performed for stone disease, 9% for allograft donation and 9% for infective pathology. Aetiology was not specified further than non-functioning kidney in 51% of cases; 80% of cases adopted minimally invasive surgery (MIS). Histology was benign in 96% of cases. Of 10,843 RNs performed, 77% were performed using MIS. Final histology was renal cell carcinoma in 87% of cases and benign histology confirmed in 9% of cases. Of 3038 NUs performed, 88% were performed using MIS. Histology confirmed malignancy in 94% of cases with transitional cell carcinoma accounting for 82% of cases overall. Of 4708 PNs performed, 74% were performed using MIS; 85% of cases were performed for T1 disease; 16% of cases overall returned benign histology. Across the cohort, 30-day mortality was 0.36%. Transfusion rates were 3.3%, 6.1%, 3.3% and 2.0% for BNs, RNs, NUs and PNs, respectively. In malignant disease, positive surgical margins were present in 0.7% of RNs, 1.2% of NUs and 7.3% of PNs.

Conclusions:

The BAUS nephrectomy dataset provides a real-world description of nephrectomy practice across England, enabling surgeons to compare their practice against a national average. This dataset allows surgeons to share data with patients enhancing informed consent and facilitating shared-decision making. Overall, MIS is widespread, and early mortality after nephrectomy is low.

Level of evidence:

2B

Feasibility and Outcomes of Renal Mass Biopsy for Anatomically Complex Renal Tumors

OBJECTIVE

To compare the feasibility and outcomes of renal mass biopsies (RMB) of anatomically complex vs non-complex renal masses.

METHODS

Our institutional renal tumor database was queried for patients who underwent RMB between 2005 and 2019 and with available nephrometry score. Complex masses were: (1) small (<2 cm), (2) entirely endophytic (nephrometry E=3), (3) hilar (h) or (4) partially endophytic (E=2) and anterior. Demographic and pathologic data were compared. Biopsies were deemed adequate if they resulted in a diagnosis. Concordance with surgical pathology was assessed. These were both presented using proportions. Factors associated with biopsy outcomes were identified using multivariable logistic regression. RMB sensitivity and specificity were calculated using contingency methods.

RESULTS

A total of 306 RBMs were included, 179 complex and 127 non-complex. A total of 199 (65%) had an extirpative procedure. Complex lesions were less likely to have an adequate biopsy (89% vs 96%, P = .03), and to be concordant with final surgical pathology from an oncologic standpoint (89% vs 97%, P = .03). There was no significant difference in concordance of histology (76% vs 86%, P = .10) or grade (48 vs 51%, P = .66). On multivariable analyses, only male gender was associated with biopsy adequacy (OR 3.31, 95% CI 1.28-8.55, P = .01). Our overall sensitivity was 93%, specificity 93%, and accuracy 93%. There were no significant differences over time in biopsy outcomes during the study period.

CONCLUSION

RMB of complex lesions is associated with excellent diagnostic yield, albeit lower than non-complex lesions. RMB should not be deferred in cases of anatomically complex lesions where additional data could improve clinical decision-making.

Surveillance for low-risk kidney cancer: a narrative review of contemporary worldwide practices

The management trend of low-risk kidney cancer over the last decade has been from treatment with radical nephrectomy, to use of nephron sparing procedures of partial nephrectomy and ablation, as well as the option of active surveillance (AS). This narrative review aims to summarise the available guidelines related to AS and review the published descriptions of regional practices on the management of low-risk kidney cancer worldwide. A search of PubMed, Google Scholar and Cochrane Library databases for studies published 2010 to June 2020 identified 15 studies, performed between 2000 and 2019, which investigated 13 different cohorts of low-risk kidney cancer patients on AS. Although international guidelines show a level of agreement in their recommendation on how AS is conducted, in terms of patient selection, surveillance strategy and triggers for intervention, cohort studies show distinct differences in worldwide practice of AS. Prospective studies showed general agreement in their predefined selection criteria for entry into AS. Retrospective studies showed that patients who were older, with greater comorbidities, worse performance status and smaller tumours were more likely to be managed with AS. The rate of percutaneous renal mass biopsy varied between studies from 2% to 56%. The surveillance protocol was different across all studies in terms of recommended modality and frequency of imaging. Of the 6 studies which had set indications for intervention, these were broadly in agreement. Despite clear criteria for intervention, patient or surgeon preference was still the reason in 11–71% of cases of delayed intervention across 5 studies. This review shows that AS is being applied in a variety of centres worldwide and that key areas of patient selection criteria and surveillance strategy have large similarities. However, the rate of renal mass biopsy and of delayed intervention varies significantly between studies, suggesting the process of diagnosing malignant SRM and decision making whilst on AS are varying in practice. Further research is needed on the diagnosis and characterisation of incidentally found small renal masses (SRM), using imaging and histology, and the natural history of these SRM in order to develop evidence-based active surveillance protocols.

Intermediate- and long-term oncological outcomes of active surveillance for localized renal masses: a systematic review and quantitative analysis

OBJECTIVE

To evaluate intermediate- and long-term oncological outcomes of active surveillance (AS) for localized renal masses (LRMs).

METHODS

This systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and registered on PROSPERO (CRD42021230416). Studies on AS for LRMs with at least 3 years' follow-up were eligible. Two review authors independently screened the literature, extracted data, and assessed risk of bias. The primary outcomes were metastasis rate, renal cell carcinoma (RCC)-specific mortality (RCC-SM) and all-cause mortality (ACM). Pooled estimates were obtained from random-effects models. Subgroup analyses were performed for small renal masses (SRMs; ≤4 cm) and non-SRMs (>4 cm).

RESULTS

We analysed 18 unique cohorts comprising 2066 patients. The pooled initial maximum tumour size was 2.8 cm (95% confidence interval [CI] 2.7-3.0) and the percutaneous biopsy rate was 28%. The pooled mean annual growth rate was 2.8 mm (95% CI 2.1-3.4). Within a pooled mean follow-up of 53 months, 2.1% (95% CI 1.0-3.6) of patients developed metastatic disease, 1.0% (95% CI 0.3-2.1) died from RCC and 22.6% (95% CI 15.8-30.2) died from any cause. For patients with SRMs (nine studies, n = 987), the pooled metastasis rate was 1.8% (95% CI 0.5-3.7), RCC-SM was 0.6% (95% CI 0-2.1), and ACM was 28.5% (95% CI 17.4-41.4). Across five studies reporting on outcomes of 239 patients with non-SRMs, the pooled metastasis rate was 5.1% (95% CI 0-17.3), RCC-SM was 2.1% (95% CI 0-8.9) and ACM was 29.1% (95% CI 13.6-47.3). This review is limited by non-standardized inclusion criteria, definitions and follow-up, data heterogeneity, limited patient numbers in sub-analyses and absence of high-quality studies.

CONCLUSIONS

Active surveillance is a safe intermediate- and long-term management option for well-selected patients with LRMs, especially those with SRMs. Limited data are available for non-SRMs, but current evidence would support further evaluation of this approach in selected patients. It is not possible to draw definitive conclusions until more high-quality data become available.

Safety and oncological outcome following radiofrequency ablation of small renal masses in a single center

OBJECTIVE

To evaluate the safety and efficacy of percutaneous CT-guided radiofrequency ablation (RFA) for small renal masses (SRMs) at a large single-institution center during a period of 12 years.

MATERIALS AND METHODS

A total of 118 patients underwent RFA for SRM between July 2006 and July 2018 at our institution. We included demographic information, comorbidity, procedural details, and oncological outcome in the analysis. Survival analysis was performed using competing risk.

RESULTS

87 males and 31 females with median age 66 years underwent RFA. Median tumor size was 23 mm. Tumor biopsy was performed in 94% of cases, of which 56% were confirmed renal cell carcinoma (RCCs). Twenty-eight patients had benign tumors or underwent treatment for recurrence of prior RCC. Median follow-up of 5 years. Median Charlson Comorbidity Index was 5. Major complications occurred in 1.7%. No change in kidney function was observed. The initial treatment response was 98%. Among patients treated for newly diagnosed radiological suspected RCC without Von Hippel-Lindau or benign biopsy (90 pts), the cumulative incidence of radiological recurrence after 5 and 10 years was 6.6% (95% CI: 0.8-12%) and 16% (95% CI: 4.2-28%), respectively. Three patients died of RCC during follow-up. The cumulative incidence of kidney cancer death was 4.5% (95% CI: 4.3-13%) after 10 years. The incidence of other-cause mortality was 50% (95% CI: 34-67%).

CONCLUSION

CT-guided RFA is a safe and effective treatment option for patients unsuitable for surgery. RFA is a good alternative to partial or radical nephrectomy for SRMs, although randomized trials comparing surgery to minimally invasive thermal ablation techniques are missing.

Adequacy of Unenhanced MRI for Surveillance of Small (Clinical T1a) Solid Renal Masses

OBJECTIVE. The purpose of this study was to determine if contrast enhancement is necessary for MRI surveillance of clinical T1a (cT1a) solid renal masses. MATERIALS AND METHODS. With institutional review board approval, 36 patients who underwent two or more contrast-enhanced (CE) MRI examinations (median, four examinations; range, two to 10 examinations) for surveillance of 39 cT1a solid renal masses between 2009 and 2019 (median time between scans, 2 years; range, 1-7 years) were evaluated. Two radiologists independently measured renal mass size and assessed tumor stage in two sessions for baseline and follow-up examinations using T1-weighted nephrographic phase CE-MRI and unenhanced single-shot T2-weighted MRI in mixed order with a 4-week washout period. Comparisons were performed using the Wilcoxon sign-rank test and Pearson correlation. Bland-Altman and intraclass correlation determined interobserver agreement. RESULTS. Mean size ± SD of renal masses on CE-MRI and T2-weighted MRI were 18 ± 5 mm (range, 9-37 mm) and 18 ± 5 mm (range, 9-37 mm) for radiologist 1 and 19 ± 7 mm (range, 10-39 mm) and 19 ± 6 mm (range, 10-39 mm) for radiologist 2 with near perfect correlation (for radiologist 1, β = 0.9897; for radiologist 2, β = 0.9317; p < .001). Interob-server agreement for measurements comparing radiologist 1 and radiologist 2 on CEMRI and T2-weighted MRI and intraobserver agreement for measurements on CE-MRI and T2-weighted MRI were excellent. Mean growth rate of renal masses measured on CE-MRI and T2-weighted MRI were 2 ± 2 mm (range, -5 to 8 mm) and 2 ± 3 mm (range, -3 to 8 mm) for radiologist 1 and 3 ± 5 mm (range, -1 to 18 mm) and 3 ± 6 mm (range, -1 to 24 mm) for radiologist 2 with high correlation (for radiologist 1, β = 0.8313 [p < .001]; for radiologist 2, β = 0.848 [p = .002]). At baseline, all tumors were subjectively cT1a on CE-MRI and T2-weighted MRI (p > .99, intraclass correlation coefficient [ICC] = 1). During follow-up, one mass progressed to T3 on CE-MRI and T2-weighted MRI for radiologist 1 and radiologist 2 (p > .99, ICC = 1). CONCLUSION. In this study, size measurements on unenhanced T2-weighted MRI had near perfect correlation to measurements using CE-MRI in cT1a solid renal masses undergoing surveillance, with high agreement between and within observers. Clinical staging did not differ comparing T2-weighted MRI and CE-MRI, with near perfect agreement. Contrast enhancement is not necessary for follow-up size measurements in cT1a solid renal masses with MRI.

Collaborative Review: Factors Influencing Treatment Decisions for Patients with a Localized Solid Renal Mass

CONTEXT

With the addition of active surveillance and thermal ablation (TA) to the urologist's established repertoire of partial (PN) and radical nephrectomy (RN) as first-line management options for localized renal cell carcinoma (RCC), appropriate treatment decision-making has become increasingly nuanced.

OBJECTIVE

To critically review the treatment options for localized, nonrecurrent RCC; to highlight the patient, renal function, tumor, and provider factors that influence treatment decisions; and to provide a framework to conceptualize that decision-making process.

EVIDENCE ACQUISITION

A collaborative critical review of the medical literature was conducted.

EVIDENCE SYNTHESIS

We identify three key decision points when managing localized RCC: (1) decision for surveillance versus treatment, (2) decision regarding treatment modality (TA, PN, or RN), and (3) decision on surgical approach (open vs minimally invasive). In evaluating factors that influence these treatment decisions, we elaborate on patient, renal function, tumor, and provider factors that either directly or indirectly impact each decision point. As current nomograms, based on preselected patient datasets, perform poorly in prospective settings, these tools should be used with caution. Patient decision aids are an underutilized tool in decision-making.

CONCLUSIONS

Localized RCC requires highly nuanced treatment decision-making, balancing patient- and tumor-specific clinical variables against indirect structural influences to provide optimal patient care.

PATIENT SUMMARY

With expanding treatment options for localized kidney cancer, treatment decision is highly nuanced and requires shared decision-making. Patient decision aids may be helpful in the treatment discussion.

Contrast-enhanced ultrasound (CEUS) imaging for active surveillance of small renal masses

PURPOSE

To assess the safety and efficacy of contrast-enhanced ultrasound (CEUS) imaging for monitoring small (< 4 cm) renal masses (SRM) in patients undergoing active surveillance (AS).

METHODS

We retrospectively selected all consecutive patients with SRMs who underwent AS for at least 6 months at our Institution between January 2014 and December 2018. CEUS imaging was performed by two experienced genitourinary radiologists at established time points. The accuracy of CEUS for monitoring SRM size was compared with that of CT scan. For solid SRMs, four enhancement patterns (EP) were recorded. Radiological progression was defined as SRM growth rate ≥ 5 mm/year.

RESULTS

Overall, 158/1049 (15.1%) patients with SRMs underwent AS. At a median follow-up of 25 months (IQR 13-39), no patient died due to renal cell carcinoma (RCC). No patients experienced CEUS-related adverse events. There was a large variability in the pattern of growth of SRMs (overall median growth rate: 0.40 mm/year), with 9.5% of SRMs showing radiological progression. The median SRM size was comparable between CEUS and CT scan examinations at all time points. The vast majority (92.7%) of SRMs did not show a change in their EP over time; and there was no association between the SRM's EP and radiological progression or SRM size. Overall, 43 (27.2%) patients underwent delayed intervention (DI); median SRM size, and median growth rate were significantly higher in these patients as compared to those continuing AS.

CONCLUSION

In experienced hands, CEUS is a safe and effective strategy for active monitoring of SRMs in well-selected patients undergoing AS.

Triggers for delayed intervention in patients with small renal masses undergoing active surveillance: a systematic review

INTRODUCTION

Patients with small renal masses (SRM) can be exposed to overdiagnosis and overtreatment. As such, active surveillance (AS) is recommended by all Guidelines for selected patients. However, it remains underutilized. One key reason is the lack of consensus on the factors prompting delayed intervention (DI). Herein we provide an updated overview of the triggers for DI in patients with SRMs initially undergoing AS.

EVIDENCE ACQUISITION

A systematic review of the English-language literature was performed according to the PRISMA statement recommendations using the MEDLINE, Cochrane Central Register of Controlled Trials and Web of Science databases.

EVIDENCE SYNTHESIS

Overall, 10 prospective studies including 1870 patients were included. Median patient age ranged between 64 and 75 years, while median tumor size between 1.7 cm to 2.3 cm. The proportion of cystic SRMs ranged from 0% to 30%. Baseline renal tumor biopsy was performed in 7-45.2% of patients. Among these, malignant histology was found in 28.5%-83.3% of cases. Overall, the median growth rate of SRMs ranged between 0.10 and 0.27 cm/year. The proportion of patients undergoing DI ranged between 7% and 44%, after a median AS period of 12-27 months. The most commonly performed type of DI was surgery. Of resected SRMs, 0% to 30% were benign. The actual triggers for DI were either tumor-related (renal mass growth, stage progression, development of local complications/symptoms) or patient-related (patient preference, improved medical conditions, or qualification for other surgical procedures). At a median follow-up of 21.7 - 57-6 months, the proportion of patients experiencing metastatic disease, cancer-specific and other-cause mortality was 0-3.1%, 0-4% and 0-45.6%, respectively.

CONCLUSIONS

The available evidence shows that both tumor-related and patient-related factors are ultimate triggers for DI in patients with SRMs undergoing AS. However, the level of evidence is still low and further research is needed to individualize AS strategies according to both tumor biology and patient-related characteristics and values.

Stereotactic Ablative Radiotherapy for ≥T1b Primary Renal Cell Carcinoma: A Report From the International Radiosurgery Oncology Consortium for Kidney (IROCK)

PURPOSE

Patients with larger (T1b, >4 cm) renal cell carcinoma (RCC) not suitable for surgery have few treatment options because thermal ablation is less effective in this setting. We hypothesize that SABR represents an effective, safe, and nephron-sparing alternative for large RCC.

METHODS AND MATERIALS

Individual patient data from 9 institutions in Germany, Australia, USA, Canada, and Japan were pooled. Patients with T1a tumors, M1 disease, and/or upper tract urothelial carcinoma were excluded. Demographics, treatment, oncologic, and renal function outcomes were assessed using descriptive statistics. Kaplan-Meier estimates and univariable and multivariable Cox proportional hazards regression were generated for oncologic outcomes.

RESULTS

Ninety-five patients were included. Median follow-up was 2.7 years. Median age was 76 years, median tumor diameter was 4.9 cm, and 81.1% had Eastern Cooperative Oncology Group performance status of 0 to 1 (or Karnofsky performance status ≥70%). In patients for whom operability details were reported, 77.6% were defined as inoperable as determined by the referring urologist. Mean baseline estimated glomerular filtration rate (eGFR) was 57.2 mL/min (mild-to-moderate dysfunction), with 30% of the cohort having moderate-to-severe dysfunction (eGFR <45mL/min). After SABR, eGFR decreased by 7.9 mL/min. Three patients (3.2%) required dialysis. Thirty-eight patients (40%) had a grade 1 to 2 toxicity. No grade 3 to 5 toxicities were reported. Cancer-specific survival, overall survival, and progression-free survival were 96.1%, 83.7%, and 81.0% at 2 years and 91.4%, 69.2%, 64.9% at 4 years, respectively. Local, distant, and any failure at 4 years were 2.9%, 11.1%, and 12.1% (cumulative incidence function with death as competing event). On multivariable analysis, increasing tumor size was associated with inferior cancer-specific survival (hazard ratio per 1 cm increase: 1.30; P < .001).

CONCLUSIONS

SABR for larger RCC in this older, largely medically inoperable cohort, demonstrated efficacy and tolerability and had modest impact on renal function. SABR appears to be a viable treatment option in this patient population.

[Geriatric specificities of localized renal cell carcinoma]

PURPOSE

To describe the epidemiology of renal cell carcinoma (RCC) and its natural history in the elderly patient. To propose adaptations of geriatric evaluation specific to RCC. Recall therapeutic options and the treatment options specific to elderly patients.

METHOD

Bibliographic research from the Medline bibliographic database (NLM Pubmed tool) and Embase, as well as on the websites of scientific societies of geriatrics, from the National Cancer Institute using the following keywords: elderly, geriatrics, renal cell carcinoma, small renal mass, diagnosis, treatment.

RESULTS

The incidence of RCC increases in France and peaks between 70 and 80 years. This increase in incidence is mainly due to the diagnosis of small renal masses (SMR). The specific mortality of RCC increases with age (at least between 75 and 95 years). Tumor biopsy, especially of SMR, should be considered in the elderly patient. The geriatric assessment of patients with CaR has no specificity apart from specific evaluation of renal function and operative risk. There is no prospective therapeutic trials dedicated to elderly patients with localized RCC. Surgical treatment requires the use of fast track protocol (the modalities of which are being elaborated) in which geriatricians play a key role throughout the process. The role of percutaneous ablative treatment should be better defined in elderly patients. However, given their low specific mortality, surveillance of SRM (at least initially) is probably an interesting option, certainly under-used, although its impact on quality of life remains to be clarified. The overarching goal of geriatric oncology must guide the decisions of care in the older patient with CaR: first, the respect of patient-specific expectations and secondly the search for an overall clinical benefit; objectives that have no reason to be restricted to elderly patients.

CONCLUSION

RCC is becoming a predominantly elderly cancer. It responds to the current general diagnostic and therapeutic guidelines. It is desirable that clinical research help to better define the respective roles of percutaneous biopsy and treatment of localized RCC.

Update on Indications for Percutaneous Renal Mass Biopsy in the Era of Advanced CT and MRI

OBJECTIVE. The objective of this article is to review the burgeoning role of percutaneous renal mass biopsy (RMB). CONCLUSION. Percutaneous RMB is safe, accurate, and indicated for an expanded list of clinical scenarios. The chief scenarios among them are to prevent treatment of benign masses and help select patients for active surveillance (AS). Imaging characterization of renal masses has improved; however, management decisions often depend on a histologic diagnosis and an assessment of biologic behavior of renal cancers, both of which are currently best achieved with RMB.

Laparoscopic Approach in Management of Renal Cell Carcinoma During Pregnancy: State of the Art

Renal cell carcinoma (RCC) is extremely rare in pregnant women. However, this is one of the most reported urologic tumors during pregnancy. The aim of this review was to evaluate RCC during pregnancy in terms of epidemiology, risk factors, diagnosis, natural history of disease, and the safety of laparoscopic approach in the management of this tumor. RCC presentation is frequently made incidentally during an ultrasonography performed for other reasons, such as hydronephrosis owing to non-neoplastic causes. The optimal time for surgery during pregnancy and the consequences of surgery on the maternal and fetal well-being are major considerations. Risks for adverse pregnancy outcomes should be explained, and the patient's decision about pregnancy termination should be considered. Ultrasound is good in diagnosing renal masses, with a sensitivity comparable to that of computed tomography only for exophytic masses larger than 3 cm. Magnetic resonance imaging is reproducible and a good, though expensive, alternative to computed tomography scans for the evaluation of renal lesions in pregnant women. Radical nephrectomy or nephron-sparing surgery are essential treatments for management of RCC. Laparoscopic surgery has historically been considered dangerous during pregnancy and avoided whenever possible, because of concerns regarding surgery-related risks, such as uterine injury, miscarriage, teratogenesis, preterm birth, and hypercapnia. The laparoscopic treatment during pregnancy is becoming increasingly accepted where feasible with low morbidity. However, the combination of a multidisciplinary approach, multi-specialty communication, and skilled surgeons can give the best possible outcomes for mother and fetus.

Current Management of Small Renal Masses, Including Patient Selection, Renal Tumor Biopsy, Active Surveillance, and Thermal Ablation

Renal cancer represents 2% to 3% of all cancers, and its incidence is rising. The increased use of ultrasonography and cross-sectional imaging has resulted in the clinical dilemma of incidentally detected small renal masses (SRMs). SRMs represent a heterogeneous group of tumors that span the full spectrum of metastatic potential, including benign, indolent, and more aggressive tumors. Currently, no composite model or biomarker exists that accurately predicts the diagnosis of kidney cancer before treatment selection, and the use of renal mass biopsy remains controversial. The management of SRMs has changed dramatically over the last two decades as our understanding of tumor biology and competing risks of mortality in this population has improved. In this review, we critically assess published consensus guidelines and recent literature on the diagnosis and management of SRMs, with a focus on patient treatment selection and use of renal mass biopsy, active surveillance, and thermal ablation. Finally, we highlight important opportunities for leveraging recent research discoveries to identify patients with SRMs at high risk for renal cell carcinoma-related mortality and minimize overtreatment and patient morbidity.

The Role of DNA Methylation in Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common kidney cancer and includes several molecular and histological subtypes with different clinical characteristics. While survival rates are high if RCC is diagnosed when still confined to the kidney and treated definitively, there are no specific diagnostic screening tests available and symptoms are rare in early stages of the disease. Management of advanced RCC has changed significantly with the advent of targeted therapies, yet survival is usually increased by months due to acquired resistance to these therapies. DNA methylation, the covalent addition of a methyl group to a cytosine, is essential for normal development and transcriptional regulation, but becomes altered commonly in cancer. These alterations result in broad transcriptional changes, including in tumor suppressor genes. Because DNA methylation is one of the earliest molecular changes in cancer and is both widespread and stable, its role in cancer biology, including RCC, has been extensively studied. In this review, we examine the role of DNA methylation in RCC disease etiology and progression, the preclinical use of DNA methylation alterations as diagnostic, prognostic and predictive biomarkers, and the potential for DNA methylation-directed therapies.

Active Surveillance for Localized Renal Masses: Tumor Growth, Delayed Intervention Rates, and >5-yr Clinical Outcomes

BACKGROUND

Active surveillance (AS) has gained acceptance as a management strategy for localized renal masses.

OBJECTIVE

To review our large single-center experience with AS.

DESIGN, SETTING, AND PARTICIPANTS

From 2000 to 2016, we identified 457 patients with 544 lesions managed with AS from our prospectively maintained kidney cancer database. A subset analysis was performed for patients with ≥5-yr follow-up without delayed intervention (DI).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Linear growth rates (LGRs) were estimated using linear regression for the initial LGR (iLGR) AS interval and the entire AS period. Overall survival (OS) and cumulative incidence of DI were estimated with Kaplan-Meier methods utilizing iLGR groups, adjusting for covariates. DI was evaluated for association with OS in Cox models.

RESULTS AND LIMITATIONS

Median follow-up was 67 mo (interquartile range [IQR] 41-94 mo) for surviving patients. Cumulative incidence of DI (n=153) after 1, 2, 3, 4, and 5 yr was 9%, 22%, 29%, 35%, and 42%, respectively. Median initial maximum tumor dimension was 2.1cm (IQR 1.5-3.1cm). Median iLGR and overall LGR were 1.9 (IQR 0-7) and 1.9 (IQR 0.3-4.2) mm/yr, respectively. Compared with the no growth group, low iLGR (hazard ratio [HR] 1.25, 95% cumulative incidence [CI] 0.82-1.91), moderate iLGR (HR 2.1, 95% CI 1.31-3.36), and high iLGR (HR 1.87, 95% CI 1.23-2.84) were associated with DI (p=0.003). The iLGR was not associated with OS (p=0.8). DI was not associated with OS (HR 1.34, 95% CI 0.79-2.29, p=0.3). Five-year cancer-specific mortality (CSM) was 1.2% (95% CI 0.4-2.8%). Of 99 patients on AS without DI for >5 yr, one patient metastasized.

CONCLUSIONS

At >5 yr, AS±DI is a successful strategy in carefully managed patients. DI often occurs in the first 2-3 yr, becoming less likely over time. Rare metastasis and low CSM rates should reassure physicians that AS is safe in the intermediate to long term.

PATIENT SUMMARY

In this report, we looked at the outcomes of patients with kidney masses who elected to enroll in active surveillance rather than immediate surgery. We found that patients who need surgery are often identified early and those who remain on active surveillance become less likely to need surgery over time. We concluded that active surveillance with or without delayed surgery is a safe practice and that, when properly managed and followed, patients are unlikely to metastasize or die from kidney cancer.

Long-term oncological outcomes after robotic partial nephrectomy for renal cell carcinoma: a prospective multicentre study

PURPOSE

This study aimed at reporting the long-term oncological outcomes of robotic partial nephrectomy (RPN) for renal cell carcinoma (RCC).

METHODS

Data from all consecutive patients who underwent RAPN for RCC from July 2009 to January 2012 in three departments of urology were prospectively collected. Overall survival (OS), cancer-specific survival (CSS) and disease free-survival (DFS) were estimated using the Kaplan-Meier method. Prognostic factors associated with CSS were sought in univariate analysis. The log-rank test was used for categorical variables and the Cox model for continuous variables.

RESULTS

110 patients were included with a median follow-up of 64.4 months [95% CI = (61.0-66.7)]. Median age was 61 years (29-83) with 62.7% of men and 37.3% of women. Median RENAL score was 6 (4-10) with elective indications accounting for 95% of cases. Out of 27 patients (24.5%) who experienced peri-operative complication, 12 patients (10.9%) had a major complication (Clavien-Dindo grade ≥ 3). The TRIFECTA achievement rate was 52.7%. Three patients (2.7%) experienced local recurrence and seven patients (6.4%) progressed to a metastatic disease. 5-year OS, CSS, DFS were 94.9, 96.8, 86.4%, respectively. In univariate analysis, no pre/peri-operative characteristic was associated with DFS. No port-site metastasis was observed and there was one case of peritoneal carcinomatosis.

CONCLUSION

In this multicenter series, long-term OS, DFS and CSS after RPN appeared comparable to large series of open partial nephrectomy, with no port-site metastasis and one case of peritoneal carcinomatosis.