Positive surgical margins during partial nephrectomy for renal cell carcinoma: Results from Canadian Kidney Cancer information system (CKCis) collaborative

The preoperative predictive factors for pathological T3a upstaging and positive surgical margin of clinical T1 renal cell carcinoma

OBJECTIVES

The objective of this study is predict positive surgical margin (PSM) and pathological T3a (pT3a) upstaging in patients with clinical T1 (cT1) renal cell carcinoma (RCC).

MATERIALS AND METHODS

159 patients who underwent radical nephrectomy (RN) or partial nephrectomy (PN) for RCC. Patients' demographic, laboratory, radiological and pathological data that could predict PSM and pT3a upstaging pre-operatively were evaluated. The categorical and continuous variables were compared between the patient groups with or without PSM and/or pT3a upstaging using Pearson's chi-square test, and independent samples t-test or the Mann-Whitney U test, respectively.

RESULTS

PT3a upstaging was detected in 32 (20.1%) patients, and PSM was detected in 28 (17.6%) patients. PT3a upstaging was detected in 27 and 5 patients who underwent open surgery and laparoscopic surgery, respectively (P < .001). In addition, pT3a upstaging was detected in 6 and 26 patients who underwent RN and PN, respectively (P < .001). Peritumoral fatty tissue thickness was 11.97 and 15.38 in the pT1 and pT3a patient groups, respectively (P = .022). In patients with pT3a upstaging, tumor size was larger, and renal nephrometry score and systemic immune-inflammation index (SII) were higher (P < .001, P < .001, and P = .022, respectively). It was determined that De Ritis ratio (DRR) and albumin-to-alkaline phosphatase (ALP) ratio (AAPR) parameters had significant prognostic values in predicting PSM (P = .024, and P = .001, respectively). ROC analysis indicated that tumor size predicted pT3a upstaging with 100% sensitivity and 98.6% specificity when its cut-off value was taken as 6.85 mm (AUC: 1.000, P < .001). In addition, logistic regression analysis revealed AAPR and DRR as significant predictors of PSM (P < .001, and P = .009, repsectively).

CONCLUSION

The findings of this study indicated that the surgical technique of choice and the type of operation, tumor size, RNS value, peritumoral fatty tissue thickness, HU values of peritumoral and tumor side fatty tissues, and DRR and SII values can predict pT3a upstaging of patients with cT1 RCC, and that AAPR and DRR values can predict PSM.

Prediction of clinically significant recurrence after partial nephrectomy. Data from the Cancer Registry of Norway with more than five years of follow-up

OBJECTIVE

To determine recurrence incidence after partial nephrectomy (PN) for renal cell carcinoma and identify predictors for local recurrence (LR) and metastasis.

MATERIAL AND METHODS

We retrospectively evaluated a cohort of 524 patients from the Cancer Registry of Norway, who underwent PN between January 2014 and December 2015 and were followed-up for >6 years. Patient demographics and pathological characteristics were correlated with recurrence and progression-free survival using Kaplan-Meier and Cox regression analyses.

RESULTS

Median patient age was 64 years, and the median tumour size was 2.6 cm. A positive surgical margin (PSM) was observed in 11% of the cases, while the LR and metastasis rates were 3.4% and 3.2%, respectively. PSM (hazard ratio [HR], 55.4; 95% confidence interval [CI], 12.55-244.6), tumour number (HR, 45.4; 95% CI, 6.5-316.1) and stage (HR, 33.5; 95% CI, 5.4-205.3) were independent predictors for LR. Undetermined margin status was also a risk factor for LR. Tumour stage (HR, 41.05; 95% CI, 8.52-197.76), tumour necrosis (HR, 1.3; 95% CI, 0.4-4.31) and age (HR, 1.07; 95% CI, 1.01-1.14) were predictors for metastasis.

CONCLUSIONS

Both local and distant recurrences after PN were rare, and the pT stage was a common predictor. PSM or indeterminate surgical margin and tumour number were LR predictors, while age at surgery and the presence of tumour necrosis predicted metastasis.

The use of indocyanine green in partial nephrectomy: a systematic review

Introduction

The aim of this review was to assess the outcomes of partial nephrectomy using indocyanine green (ICG) regarding ischemia time, positive surgical margins (PSM), estimated blood loss (EBL) and estimated GFR reduction while also suggesting the optimal dosage scheme.

Material and methods

A systematic review was performed using Medline (PubMed), ClinicalTrials.gov, and Cochrane Library (CENTRAL) databases, in concordance with the PRISMA statement. Studies in English regarding the use of indocyanine green in partial nephrectomy were reviewed. Reviews and meta-analyses, editorials, perspectives, and letters to the editors were excluded.

Results

Individual ICG dose was 5 mg in most of the studies. The mean warm ischemia time (WIT) on each study ranged from 11.6 minutes to 27.2 minutes. The reported eGFR reduction ranged from 0% to 15.47%. Lowest mean EBL rate was 48.2 ml and the highest was 347 ml. Positive surgical margin rates were between 0.3% to 11%.

Conclusions

Indocyanine green seems to be a useful tool in partial nephrectomy as it can assist surgeons in identifying tumor and its related vasculature. Thereby, warm ischemia time can be reduced and, in some cases, selective ischemia can be implemented leading to better renal functional preservation.

Comparison of patients with renal cell carcinoma in adjuvant therapy trials to a real-world population

PURPOSE

To compare characteristics and outcomes of patients included versus those not in adjuvant therapy trials post complete resection of renal cell carcinoma (RCC).

METHODS

Adult patients following complete resection for clear cell RCC between January 1, 2011, and March 31, 2021, were included. Patients had intermediate high, high risk nonmetastatic disease (modified UCLA Integrated Staging System) or fully resected metastatic (M1) disease as per the inclusion criteria of adjuvant studies. Demographic, clinical, and outcomes between trial and nontrial patients were compared.

RESULTS

Of 1,459 eligible patients, 63 (4.3%) participated in an adjuvant trial. Disease characteristics were similar between groups. Trial patients were younger (mean age 58.1 vs. 63.6 years; P < 0.0001) and had lower Charlson Comorbidity Index scores (mean 4.2 vs. 4.9; P = 0.009). Unadjusted disease-free survival (DFS) at 5 years for trial patients was 48.6% and 39.2% for nontrial patients (HR 0.71, 0.48-1.05, P = 0.08). Median DFS was higher for trial patients in comparison to nontrial patients (4.4 years, IQR 1.7- not reached; vs. 3.0 years, IQR 0.8-8.6; P = 0.08). Cancer specific survival (CSS) at 5 years for trial patients was 85.2% in comparison to 78.6% for nontrial patients (HR 0.45, 0.22-0.92, P = 0.03). Unadjusted estimated overall survival (OS) at 5 years was 80.8% for trial patients and 74.8% (HR 0.42, 0.18-0.94; P = 0.04) for nontrial patients.

CONCLUSIONS

Patients in adjuvant trials were younger and healthier with longer CSS and OS in comparison to those not included in adjuvant trials. These findings may have implications when we generalize trial results to real world patients.

Robot-assisted partial nephrectomy for complex renal tumors: Analysis of a large multi-institutional database

INTRODUCTION

Highly complex renal masses pose a challenge to urologic surgeons' ability to perform robotic partial nephrectomy (RPN). Given the increased utilization of the robotic approach for small renal masses, we sought to characterize the outcomes and determine the safety and feasibility of RPN for complex renal masses from our large multi-institutional cohort.

METHODS

We performed a retrospective analysis of patients with R.E.N.A.L. Nephrometry Scores ≥10 who underwent RPN in our multi-institutional cohort (N = 372). Baseline demographic, clinical and tumor related characteristics were evaluated with the primary endpoint of trifecta achievement (defined as negative surgical margin, no major complications, and warm ischemia time ≤25 min). Relationships between variables were assessed using the chi-square test of independence, Fisher exact test, Mann-Whitney U test, and Kruskal Wallis test. Logistic regression was used to evaluate the relationship between baseline characteristics and trifecta achievement.

RESULTS

Of 372 patients in the study, mean age was 58 years, and median BMI was 30.49 kg/m². The median tumor size was 4.3 cm (3.0-5.9 cm). Most of the patients had R.E.N.A.L. scores of 10 (n = 253; 67.01%). Overall, trifecta was achieved in 72.04% of patients. Stratifying intraoperative and postoperative outcomes by R.E.N.A.L. scores, there was no significant difference in trifecta achievement, operative time, warm ischemia time (WIT), open conversion, major complication, or positive margin rates. Length of hospital stay was significantly longer for higher R.E.N.A.L. scores (median days 2 vs. 1, P = 0.012). Multivariate analyses for factors associated with trifecta achievement concluded that age and baseline eGFR were independently associated with trifecta achievement.

CONCLUSION

RPN is a safe and reproducible procedure for complex tumors with R.E.N.A.L. Nephrometry scores ≥10. Our results suggest excellent rates of trifecta achievement and short-term functional outcomes when performed by experienced surgeons. Long-term oncological and functional evaluation are needed to further support this conclusion.

Laparoscopic and Open Nephron-Sparing Surgery for Radius Exophytic/Endophytic Nearness Anterior/ Posterior Location Nephrometry Score 7 and Higher Kidney Tumors: A Comparison of Oncological and Functional Outcomes Using the Pentafecta Score

OBJECTIVE

This study aimed to evaluate oncological and functional outcomes of nephron- sparing surgery by comparing open and laparoscopic approaches in a consecutive series of patients with intermediate and high complexity renal masses.

MATERIALS AND METHODS

We retrospectively reviewed all nephron-sparing surgery cases in 2 referral centers from January 2013 to January 2020. Tumor complexity was graded according to radius exophytic/endophytic nearness anterior/posterior location nephrometry score. Patients with a single kidney tumor with a radius exophytic/endophytic nearness anterior/posterior location score ≥ 7 were evaluated. Exclusion criteria were solitary kidney, multiple/bilateral tumors, and a low radius exophytic/endophytic nearness Anterior/Posterior location score (<7). Patients were divided according to the surgical approach: the laparoscopic tumor enucleation and the open wedge resection groups. The Trifecta and Pentafecta score achievement rates were assessed.

RESULTS

Two hundred thirteen patients were included in the analysis, 76 in laparoscopic tumor enucleation group and 137 in the open wedge resection group. There were no statistically significant differences in preoperative data between laparoscopic tumor enucleation and open wedge resection groups, except for the higher percentage of T1a masses in the latter group. The mean 24-hour blood loss and length of stay were higher in the open wedge resection group. Minor and major postoperative complication rates were comparable. No significant difference in terms of the Trifecta score was reported. Pentafecta score was achieved in 35/76 (46.1%) and 61/137 (44.5%) cases in the laparoscopic tumor enucleation and open wedge resection groups, respectively.

CONCLUSION

Our study showed that laparoscopic tumor enucleation was associated with significantly lower blood and length of stay. Postoperative complications and the achievement of the Pentafecta score were similar in both surgical approaches.

Adjuvant therapy for renal cell carcinoma: 2023 Canadian Kidney Cancer Forum consensus statement

INTRODUCTION

Several recent randomized trials evaluated the impact of adjuvant immune checkpoint inhibitor (ICI)-based therapy on post-surgical outcomes in renal cell carcinoma (RCC), with disparate results. The objective of this consensus statement is to provide data-driven guidance regarding the use of ICIs after complete resection of clear-cell RCC in a Canadian context.

METHODS

An expert panel of genitourinary medical oncologists, urologic oncologists, and radiation oncologists with expertise in RCC management was convened in a dedicated session during the 2022 Canadian Kidney Cancer Forum in Toronto, Canada. Topic statements on the management of patients after surgery for RCC, including counselling, risk stratification, indications for medical oncology referral, appropriate followup, eligibility and management for adjuvant ICIs, as well as treatment options for patients with recurrence who received adjuvant immunotherapy, were discussed. Participants were asked to vote if they agreed or disagreed with each statement. Consensus was achieved if greater than 75% of participants agreed with the topic statement.

RESULTS

A total of 22 RCC experts voted on 14 statements. Consensus was achieved on all topic statements. The panel felt patients with clear-cell RCC at increased risk of recurrence after surgery, as per the Keynote-564 group definitions, should be counselled about recurrence risk by a urologist, should be informed about the potential role of adjuvant ICI systemic therapy, and be offered referral to discuss risks and benefits with a medical oncologist. The panel felt that one year of pembrolizumab is currently the only regimen that should be considered if adjuvant therapy is selected. Panelists emphasized current opinions are based on disease-free survival given the available results. Significant uncertainty regarding the benefit and harms of adjuvant therapy remains, primarily due to a lack of consistent benefit observed across similar trials of adjuvant ICI-based therapies and immature overall survival (OS) data.

CONCLUSIONS

This consensus document provides guidance from Canadian RCC experts regarding the potential role of ICI-based adjuvant systemic therapy after surgery. This rapidly evolving field requires frequent evidence-based re-evaluation.

Positive surgical margins may not affect the survival of patients with renal cell carcinoma after partial nephrectomy: A meta-analysis based on 39 studies

Background

So far, whether positive surgical margin(PSM) has adverse effects on the prognosis of patients is still controversial, so we designed this study to systematically evaluate the effect of PSM on the prognosis of patients with renal cell carcinoma (RCC) after partial nephrectomy (PN).

Methods

On the basis of three electronic databases (PubMed, Embase and the Cochrane Library) up to May 2022, all case-control studies (CCSs) comparing the effects of PSM and negative surgical margin (NSM) after PN on the oncological results of RCC patients were included. Two evaluators independently conducted a systematic literature search and extracted the data we needed. The methodological quality of all studies was evaluated by the modified Newcastle-Ottawa scale. The odds ratio (OR) was used to describe the results for dichotomous variables, and the meta-analysis was conducted using Cochrane Review Manager 5.2 and Stata 14.2.

Results

A total of 39 studies involving 21461 patients were included in our meta-analysis. The pooled results showed that the rates of tumor recurrence (OR 3.93, 95% CI 2.95-5.24; p < 0.00001) and metastasis (OR 4.63, 95% CI 3.11-6.88; p < 0.00001) in the PSM group were significantly higher than those in the NSM group. However, there were no significant differences in the rates of all-cause death (OR 1.35, 95% CI 0.92-1.99; p = 0.13) or cancer-specific death (OR 0.99, 95% CI 0.51-1.94; p = 0.99) between the two groups. In addition, subgroup analyses were carried out according to different average follow-ups, which revealed similar results.

Conclusion

Insignificant differences in survival between the PSM and NSM groups were observed, although significant differences in recurrence and metastasis in the PSM group were reported. Our study supported that close monitoring might be another effective choice for patients with PSM after PN. Considering the possible limitations, we recommended cautious interpretation of our results.

Robotic-assisted tumor enucleation versus standard margin partial nephrectomy: Perioperative, renal functional, and oncologic outcomes for low and intermediate complexity renal masses

PURPOSE

Standard margin partial nephrectomy (SPN) with sharp incision across normal renal parenchyma carries perioperative morbidity and renal functional implications. Tumor enucleation (TE) is an alternative approach using a natural plane of dissection around the tumor pseudocapsule to maximize parenchymal preservation. We compared perioperative, functional, and oncologic outcomes for robotic-assisted TE to SPN.

MATERIALS AND METHODS

Patients ≥18 years of age undergoing robotic-assisted TE or SPN were included (2008-2020). Baseline demographics and tumor characteristics were compared. Perioperative, renal functional, and oncologic outcomes were assessed for comparative effectiveness.

RESULTS

A total of 467 patients were included with 176 (37.7%) TE and 291 (62.3%) SPN. Baseline characteristics and final histology were comparable; 18% of patients had baseline stage 3 chronic kidney disease. TE had lower median blood loss, operative time, length of stay, and fewer complications compared to SPN. Positive margin rates were higher for TE vs. SPN (8.5% vs. 3.4%, P = 0.04) with similar recurrence rates (2.3% vs. 3.4%, P = 0.48) and no difference in cancer-specific or overall survival with median 4.0 years follow-up. Baseline estimated glomerular filtration rate was comparable (76.1 vs. 78.2, P = 0.63) while renal function in the first year was better preserved with TE (74.6 vs. 68.1, P < 0.001) showing an 8-point estimated glomerular filtration rate (P = 0.001) advantage after adjustment. The rate of stage ≥3 chronic kidney disease by 12 months was lower for TE compared to SPN (21.5% vs. 34.1%, P = 0.006).

CONCLUSIONS

TE is an alternative approach to SPN associated with favorable perioperative and renal functional outcomes. While positive margin rates are higher, longer-term recurrence rates are no different suggesting pseudocapsule disruption during TE has limited impact on oncologic outcomes.

Prognostic Factors for Localized Clear Cell Renal Cell Carcinoma and Their Application in Adjuvant Therapy

Simple Summary

Approximately one fifth of patients with newly diagnosed renal cell carcinoma (RCC) present with metastatic disease and over one third of the remaining patients with localized RCC will eventually have metastases spread to distant sites after complete resection of the primary tumor in the kidney. Usually, disease recurrence is observed within the first five years of follow-up, but late recurrences after five years are seen in up to 10% of patients. Despite novel biomarkers, simple histopathological factors, such as tumor size, tumor grade, and tumor extension into the blood vessels or beyond the kidney, are still valid features in predicting the risk of disease recurrence after surgery. The optimal set of prognostic factors remains unclear. The results from ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic features that help to define high-risk patients for disease recurrence.

Abstract

Approximately 20% of patients with renal cell carcinoma (RCC) present with primarily metastatic disease and over 30% of patients with localized RCC will develop distant metastases later, after complete resection of the primary tumor. Accurate postoperative prognostic models are essential for designing personalized surveillance programs, as well as for designing adjuvant therapy and trials. Several clinical and histopathological prognostic factors have been identified and adopted into prognostic algorithms to assess the individual risk for disease recurrence after radical or partial nephrectomy. However, the prediction accuracy of current prognostic models has been studied in retrospective patient cohorts and the optimal set of prognostic features remains unclear. In addition to traditional histopathological prognostic factors, novel biomarkers, such as gene expression profiles and circulating tumor DNA, are extensively studied to supplement existing prognostic algorithms to improve their prediction accuracy. Here, we aim to give an overview of existing prognostic features and prediction models for localized postoperative clear cell RCC and discuss their role in the adjuvant therapy trials. The results of ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic factors and biomarkers that help to define patients at high risk for disease recurrence.

How accurate is radiological imaging for perirenal fat and renal vein invasion in renal cell carcinoma?

OBJECTIVE

To evaluate the accuracy of radiological staging, especially renal venous and perirenal fat invasion, in renal cell carcinoma (RCC).

MATERIAL AND METHODS

Data of 4823 renal tumour patients from Renal Tumor Database of Association of Uro-oncology in Turkey were evaluated. Of 4823 patients, 3309 RCC patients had complete radiological, and histopathological data were included to this study. The Pearson chi-squared test (χ² ) was used to compare radiological and histopathological stages.

RESULTS

The mean (SD) age of 3309 patients was 58 (12.3). Preoperative radiological imaging was performed using computed tomography (CT) (n = 2510, 75.8%) or magnetic resonance imaging (MRI) (n = 799, 24.2%). There was a substantial concordance between radiological and pathological staging (к = 0.52, P < .001). Sensitivities of radiological staging in stages I, II, III and IV were 90.7%, 67.3%, 27.7% and 64.2%, respectively. The sensitivity in stage III was lower than the other stages. Subanalysis of stage IIIa cases revealed that, for perirenal fat invasion and renal vein invasion, sensitivity values were 15.4% and 11.3%, respectively.

CONCLUSIONS

There was a substantial concordance between radiological (CT and/or MRI) and pathological T staging in RCC. However, this is not true for T3 cases. Sensitivity of preoperative radiological imaging in patients with pT3a tumours is insufficient and lower than the other stages. Consequently, preoperative imaging in patients with T3 RCC has to be improved, in order to better inform the patients regarding prognosis of their disease.

Does a Positive Surgical Margin After Nephron Sparing Surgery Affect Oncological Outcome in Renal Cell Carcinoma? A Systematic Review and Meta-analysis

We systematically evaluated the impact of positive surgical margins (PSM) on oncological outcomes after partial nephrectomy for renal cell carcinoma. Forty-two studies comprising 101,153 subjects were included and five distinct meta-analyses were performed. PSM was associated with increased risk of local recurrence (hazard ratio (HR) 6.11-high certainty), metastasis (HR 3.29-moderate certainty), overall relapse (HR 2.25-high certainty), overall mortality (HR 1.30-moderate certainty), and may be associated with increased cancer-specific mortality (HR 1.91-low certainty). Patients with PSM should be counseled for the possibility of additional surgery, novel adjuvant therapies, and more rigorous surveillance.

Impact of margin status on survival after radical nephrectomy for renal cell carcinoma

BACKGROUND

Data about the impact of surgical margin positivity on patient outcomes following radical nephrectomy (RN) for renal cell carcinoma (RCC) is limited. We evaluate the effect of positive surgical margins (PSMs) on relapse-free survival (RFS) and overall survival (OS.) METHODS: Clinicopathologic data of patients who underwent RN for RCC was analyzed based on margin status. χ² and Student t test were used to compare groups. Cox regression analysis was used for the analysis. Kaplan-Meier method was used for survival curves.

RESULTS

A total of 485 patients who underwent RN for RCC were analyzed. Most patients with T1/T2 stage had NSM. Most patients with T4 had PSM. T3 patients were split between the two groups. Analysis of the T3 group showed shorter RFS in the PSM group at 3 years (hazard ratio [HR]: 4.3, p = .01), and 5 years (HR: 4.3, p = .01.) OS analysis showed worse OS in PSM but not statistically significant. There was a significant association between PSM and laterality (p = .023) and histologic type (p = .025.) CONCLUSIONS: PSM was associated with shorter RFS after RN in T3 RCC patients. There was a trend towards worse OS in the PSM group, but it did not reach statistical significance. Laterality and histologic type were associated with surgical margin status.

Impact of Positive Surgical Margins After Partial Nephrectomy

Background

The impact of positive surgical margins (PSMs) after partial nephrectomy (PN) is controversial.

Objective

To evaluate the risk factors for a PSM and its impact on overall survival.

Design, setting, and participants

This is a retrospective study of 388 patients were submitted to PN between November 2005 and December 2016 in a single centre. Two groups were created: PSM and negative surgical margin (NSM) after PN. A p value of <0.05 was considered significant.

Outcome measurements and statistical analysis

Relationships with outcome were assessed using univariable and multivariable tests and log-rank analysis.

Results and limitations

The PSM rate was 3.8% (N = 16). The mean age at the time of surgery (PSM group: 64.1 ± 11.3 vs NSM group: 61.8 ± 12.8 yr, p =  0.5) and the mean radiological tumour size (4.0 ± 1.5 vs 3.4 ± 1.8 cm, p =  0.2) were similar. Lesion location (p =  0.3), surgical approach (p =  0.4), warm ischaemia time (p =  0.9), and surgery time (p =  0.06) had no association with PSM. However, higher surgeon experience was associated with a lower PSM incidence (2.6% if ≥30 PNs vs 9.6% if <30 PNs; p =  0.02). Higher operative blood loss (p =  0.02), higher-risk tumours (p =  0.03), and larger pathological size (p =  0.05) were associated with an increase in PSM. In the PSM group, recurrence rate (18.7% vs 4.2%, p =  0.007) and secondary total nephrectomy rate (25% vs 4.4%, p <  0.001) were higher. However, overall survival was similar. Multivariate analysis revealed that high-risk tumour (p =  0.05) and low experience (p =  0.03) could predict a PSM. Limitations include retrospective design and reduced follow-up time.

Conclusions

PSMs were mainly associated with high-risk pathological tumour (p =  0.05) and low-volume surgeon experience. Recurrence rate and need for total nephrectomy were higher in that group, but no impact on survival was noticed.

Patient summary

The impact of positive surgical margins (PSMs) after partial nephrectomy is a matter of debate. In this study, we found that PSMs were mainly associated with aggressive disease and low surgeon experience.

Effect of phase of enhancement on texture analysis in renal masses evaluated with non-contrast-enhanced, corticomedullary, and nephrographic phase-enhanced CT images

OBJECTIVE

To compare texture analysis (TA) features of solid renal masses on renal protocol (non-contrast enhanced [NECT], corticomedullary [CM], nephrographic [NG]) CT.

MATERIALS AND METHODS

A total of 177 consecutive solid renal masses (116 renal cell carcinoma [RCC]; 51 clear cell [cc], 40 papillary, 25 chromophobe, and 61 benign masses; 49 oncocytomas, 12 fat-poor angiomyolipomas) with three-phase CT between 2012 and 2017 were studied. Two blinded radiologists independently assessed tumor heterogeneity (5-point Likert scale) and segmented tumors. TA features (N = 25) were compared between groups and between phases. Accuracy (area under the curve [AUC]) for RCC versus benign and cc-RCC versus other masses was compared.

RESULTS

Subjectively, tumor heterogeneity differed between phases (p < 0.01) and between tumors within the same phase (p = 0.03 [NECT] and p < 0.01 [CM, NG]). Inter-observer agreement was moderate to substantial (intraclass correlation coefficient = 0.55-0.73). TA differed in 92.0% (23/25) features between phases (p < 0.05) except for GLNU and f6. More TA features differed significantly on CM (80.0% [20/25]) compared with NG (40.0% [10/25]) and NECT (16.0% [4/25]) (p < 0.01). For RCC versus benign, AUCs of texture features did not differ comparing CM and NG (p > 0.05), but were higher for 20% (5/25) and 28% (7/25) of features comparing CM and NG with NECT (p < 0.05). For cc-RCC versus other, 36% (9/25) and 40% (10/25) features on CM had higher AUCs compared with NECT and NG images (p < 0.05).

CONCLUSION

Texture analysis of renal masses differs, when evaluated subjectively and quantitatively, by phase of CT enhancement. The corticomedullary phase had the highest discriminatory value when comparing masses and for differentiating cc-RCC from other masses.

KEY POINTS

• Subjectively evaluated renal tumor heterogeneity on CT differs by phase of enhancement. • Quantitative CT texture analysis features in renal tumors differ by phases of enhancement with the corticomedullary phase showing the highest number and most significant differences compared with non-contrast-enhanced and nephrographic phase images. • For diagnosis of clear cell RCC, corticomedullary phase texture analysis features had improved accuracy of classification in approximately 40% of features studied compared with non-contrast-enhanced and nephrographic phase images.

Importance of phase enhancement for machine learning classification of solid renal masses using texture analysis features at multi-phasic CT

OBJECTIVE

To compare machine learning (ML) of texture analysis (TA) features for classification of solid renal masses on non-contrast-enhanced CT (NCCT), corticomedullary (CM) and nephrographic (NG) phase contrast-enhanced (CE) CT.

MATERIALS AND METHODS

With IRB approval, we retrospectively identified 177 consecutive solid renal masses (116 renal cell carcinoma [RCC]; 51 clear cell [cc], 40 papillary, 25 chromophobe and 61 benign tumors; 49 oncocytomas and 12 fat-poor angiomyolipomas) with renal protocol CT between 2012 and 2017. Tumors were independently segmented by two blinded radiologists. Twenty-five 2-dimensional TA features were extracted from each phase. Diagnostic accuracy for 1) RCC versus benign tumor and 2) cc-RCC versus other tumor was assessed using XGBoost.

RESULTS

ML of texture analysis features on different phases achieved mean area under the ROC curve (AUC [SD]), sensitivity/specificity for 1) RCC vs benign = 0.70(0.19), 96%/32% on CM-CECT and 0.71(0.14), 83%/58% on NG-CECT and; 2) cc-RCC vs other = 0.77(0.12), 49%/90% on CM-CECT and 0.71(0.16), 22%/94% on NG-CECT. There was no difference in AUC comparing CECT to NCCT (p = 0.058-0.54) and no improvement when combining data across all three phases compared single-phase assessment (p = 0.39-0.68) for either outcome. AUCs decreased when ML models were trained with one phase and tested on a different phase for both outcomes (RCC;p = 0.045-0.106, cc-RCC; < 0.001).

CONCLUSION

Accuracy of machine learning classification of renal masses using texture analysis features did not depend on phase; however, models trained using one phase performed worse when tested on another phase particularly when associating NCCT and CECT. These findings have implications for large registries which use varying CT protocols to study renal masses.

Impact of positive surgical margins on survival after partial nephrectomy in localized kidney cancer: analysis of the National Cancer Database

BACKGROUND

The impact of positive surgical margins (PSM) on outcomes in partial nephrectomy (PN) is controversial. We investigated impact of PSM for patients undergoing PN on overall survival (OS) in different stages of renal cell carcinoma (RCC).

METHODS

Retrospective analysis of patients from the US National Cancer Database who underwent PN for cT1a-cT2b N0M0 RCC between 2004-13. Patients were stratified by pathological stage (pT1a, pT1b, pT2a, pT2b, and pT3a [upstaged]) and analyzed by margin status. Cox Regression multivariable analysis (MVA) was performed to investigate associations of PSM and covariates on all-cause mortality (ACM). Kaplan-Meier analysis (KMA) of OS was performed for PSM versus negative margin (NSM) by pathological stage. Sub-analysis of Charlson Comorbidity Index 0 (CCI=0) subgroup was conducted to reduce bias from comorbidities.

RESULTS

We analyzed 42,113 PN (pT1a: 33,341 [79.2%]; pT1a, pT1b: 6689 [15.9%]; pT2a: 757 [1.8%]; pT2b: 165 [0.4%]; and pT3a: upstaged 1161 [2.8%]). PSM occurred in 6.7% (2823) (pT1a: 6.5%, pT1b: 6.3%, pT2a: 5.9%, pT2b: 6.1%, pT3a: 14.1%, P<0.001). On MVA, PSM was associated with 31% increase in ACM (HR 1.31, P<0.001), which persisted in CCI=0 sub-analysis (HR: 1.25, P<0.001). KMA revealed negative impact of PSM vs. NSM on 5-year OS: pT1 (87.3% vs. 90.9%, P<0.001), pT2 (86.7% vs. 82.5%, P=0.48), and upstaged pT3a (69% vs. 84.2%, P<0.001).

CONCLUSIONS

PSM after PN was independently associated with across-the-board decrement in OS, which worsened in pT3a disease and persisted in sub-analysis of patients with CCI=0. PSM should prompt more aggressive surveillance or definitive resection strategies.

The Clinicopathological Risk Factors in Renal Cell Cancer for the Oncological Outcomes Following Nephron-Sparing Surgery: A PRISMA Systematic Review and Meta-Analysis

Background and Objectives: Published data from individual studies present conflicting evidence about the relationship between clinicopathological risk factors and oncological outcomes in renal cell cancer (RCC) following nephron-sparing surgery (NSS). This study was conducted to explore the potential risk factors for RCC progress after NSS. Methods: Studies published in PubMed, Web of Science, and EMBASE were systematically reviewed from inception to March 2019 to determine risk factors for RCC following NSS. The predictive ability of identified predictors was assessed by hazard ratios (HRs) with 95% confidence intervals (CIs). A fixed-effect or random-effect was used to pool the estimates. Subgroup analyses were performed to explore the source of heterogeneity. Results: Seventeen studies including 38,522 patients with RCC were analyzed. The meta-analysis indicated that positive surgical margin (pooled HR = 1.47; 95% CI:1.24-1.73; P < 0.001), higher Fuhrman grade (pooled HR = 1.58; 95% CI:1.10-2.28; P = 0.013), higher pathological stage (pooled HR = 1.72; 95% CI:1.40-2.12; P < 0.001) and large tumor size (pooled HR = 1.09; 95% CI:1.03-1.16; P = 0.003) were significantly associated with recurrence risk. However, age (pooled HR = 1.00; 95% CI: 1.00-1.01; P = 0.257), sex (male vs. female) (pooled HR = 1.04; 95% CI: 0.89-1.21; P = 0.605) and surgical approach (laparoscope vs. open) (pooled HR = 0.80; 95% CI: 0.59-1.07; P = 0.129) had no effect on recurrence after NSS. In addition, we found that positive surgical margin was significantly associated with recurrence-free survival (pooled HR = 1.87; 95% CI: 1.32-2.66; P < 0.001) and overall mortality (pooled HR = 1.15; 95% CI: 1.07-1.23; P < 0.001), as well as large tumor size for recurrence-free survival (pooled HR = 1.18; 95% CI: 1.06-1.30; P = 0.002)and overall mortality (pooled HR = 1.01; 95% CI: 1.00-1.02; P = 0.004). Conclusions: Unfavorable pathological characteristics were distinctly related to worse oncological outcomes in RCC patients following NSS. These results may contribute to proposed prediction models for RCC patients to aid in counseling and risk stratification.

Visible near infrared reflectance molecular chemical imaging of human ex vivo carcinomas and murine in vivo carcinomas

SIGNIFICANCE

A key risk faced by oncological surgeons continues to be complete removal of tumor. Currently, there is no intraoperative imaging device to detect kidney tumors during excision.

AIM

We are evaluating molecular chemical imaging (MCI) as a technology for real-time tumor detection and margin assessment during tumor removal surgeries.

APPROACH

In exploratory studies, we evaluate visible near infrared (Vis-NIR) MCI for differentiating tumor from adjacent tissue in ex vivo human kidney specimens, and in anaesthetized mice with breast or lung tumor xenografts. Differentiation of tumor from nontumor tissues is made possible with diffuse reflectance spectroscopic signatures and hyperspectral imaging technology. Tumor detection is achieved by score image generation to localize the tumor, followed by application of computer vision algorithms to define tumor border.

RESULTS

Performance of a partial least squares discriminant analysis (PLS-DA) model for kidney tumor in a 22-patient study is 0.96 for area under the receiver operating characteristic curve. A PLS-DA model for in vivo breast and lung tumor xenografts performs with 100% sensitivity, 83% specificity, and 89% accuracy.

CONCLUSION

Detection of cancer in surgically resected human kidney tissues is demonstrated ex vivo with Vis-NIR MCI, and in vivo on mice with breast or lung xenografts.

Roles for active surveillance in renal cancer

PURPOSE OF REVIEW

With this review, we describe the most recent advances in active surveillance as well as diagnosis and management of small renal masses (SRMs).

RECENT FINDINGS

We discuss diagnosis, differentiation of solid from cystic lesions, risk prediction and treatment of the SRM. A better understanding of the disease facilitates the use of more conservatory treatments, such as active surveillance. Active surveillance has been increasingly accepted not only for SRM, but also for larger tumors and even metastatic patients. Exiting advances in risk prediction will help us define which patients can be safely managed with active surveillance and which require immediate treatment. Meanwhile, the use of renal tumor biopsies is still an important tool for these cases.

SUMMARY

Active surveillance is an option for many patients with renal masses. Noninvasive methods for diagnosis and risk prediction are being developed, but meanwhile, renal tumor biopsy is a useful tool. A better understanding of the disease increases the number of patients who can undergo active surveillance fully certain of the safety of their management.

The Correlation of Clinicopathological Features With the Status of Surgical Margins in Renal Cell Cancer Patients Following Nephron-Sparing Surgery: A Systematic Review and Meta-Analysis

Objectives: The aim of this study was to evaluate the correlation of various clinicopathological variables with positive surgical margins (PSMs) in renal cell cancer (RCC) patients after nephron-sparing surgery (NSS). Methods: A systematic search of PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure (CNKI) was performed to identify studies that compared PSMs with negative surgical margins (NSMs) and were published up to December 2018. Outcomes of interest included perioperative and postoperative variables, and the data were pooled by odds ratios (ORs)/standard mean differences (SMD) with 95% confidence intervals (CIs) to evaluate the strength of such associations. STATA 12.0 software was used for all statistical analyses. Results: Based on the inclusion and exclusion criteria, 13 studies including 47,499 patients with RCC were analyzed. The results showed that higher Furhman grade (pooled OR = 1.25; 95% CI: 1.14-1.37; P < 0.001), higher pathological stage (pooled OR = 2.67; 95% CI: 2.05-3.50; P < 0.001), non-clear cell RCC (non-ccRCC) histology (pooled OR = 0.78; 95% CI: 0.72-0.84; P < 0.001), and non-white race (pooled OR = 0.90; 95% CI: 0.82-0.99; P = 0.026) were significantly associated with high risk of PSMs. However, age (pooled SMD = 0.09; 95% CI: -0.01-0.20; P = 0.078), gender (female vs. male) (pooled OR = 1.04; 95% CI: 0.96-1.12; P = 0.377), tumor laterality (left vs. right) (pooled OR = 1.09; 95% CI: 0.84-1.42; P = 0.501), tumor focality (unifocal vs. multifocal) (pooled OR = 0.67; 95% CI: 0.23-1.90; P = 0.445), tumor size (pooled SMD = 0.03; 95% CI: -0.10-0.15; P = 0.685), and surgical approach (open vs. non-open) (pooled OR = 0.94; 95% CI: 0.62-1.42; P = 0.763) had no relationship with PSMs. Sensitivity analysis showed that all models were stable, and no publication bias was observed in our study. Conclusions: The present findings demonstrate that the presence of PSMs was associated with higher Furhman grade and higher pathological stage. Additionally, non-white patients with non-ccRCC histology had a high risk of PSMs after NSS. Further multicenter and long-term follow-up studies are required to verify these findings.

Canadian content at GU-ASCO 2014: Highlights of research involving Canadian researchers

The 2014 Genitourinary Cancers Symposium (GU-ASCO 2014) provided an opportunity for researchers from around the world to present their research in a variety of fields, including prostate, renal cell, penile, urethral and testicular cancers. Over the symposium's 3 days, Canadian researchers were well-represented, with a number of oral abstract podium presentations and many more research posters. The following section provides brief summaries of some of the most interesting work involving Canadians presented at GU-ASCO 2014 and a listing of all the studies that included contributions from Canadian researchers.