Partial nephrectomy versus ablative therapies for cT1a renal masses: A Systematic Review and meta-analysis

A New Nephrometry Score for Predicting Positive Surgical Margin After Laparoscopic Partial Nephrectomy

PURPOSE

To introduce the KESKIN ratio as a novel predictor of positive surgical margin (PSM) after laparoscopic partial nephrectomy (PN) and to evaluate other clinical characteristics and nephrometry scores (including RENAL, PADUA, and C-index) for predicting PSM.

METHODS

We retrospectively analyzed 95 patients who underwent laparoscopic PN between June 2020 and April 2023. The KESKIN ratio was defined for all patients. The KESKIN ratio, tumor and patient-related paramaters, and nephrometry scores were analyzed to predict PSM.

RESULTS

Positive surgical margin was found in 12 of 95 patients (12.6%). There was no statistical difference between the PSM and negative surgical margin (NSM) groups in RENAL, PADUA, and C-index scores. Only the KESKIN ratio was found to be a statistically significant predictor of PSM in both univariate and multivariate regression analysis (p = 0.007 and p = 0.043, respectively). Mean endophytic diameter and endophytic percentage were found to be statistically significant predictors of PSM in only univariate analysis (p = 0.005 and p = 0.01, respectively). The value of 0.5 was determined as the cut-off value for the KESKIN ratio. Values higher than 0.5 indicate an increase in PSM.

CONCLUSIONS

The KESKIN ratio is a novel, easily measurable, and calculable image-based parameter that can be used to predict PSM after laparascopic PN. If externally validated in a larger patient population, the KESKIN ratio may be used in future versions of the current nephrometry scoring systems for predicting the PSM.

Perioperative and Oncological Outcomes of Percutaneous Radiofrequency Ablation versus Partial Nephrectomy for cT1a Renal Cancers: A Retrospective Study on Groups with Similar Clinical Characteristics

Over the recent years, progress in imaging techniques has led to an increased detection of kidney tumours, including small renal masses. While surgery is still the standard of care, there is a growing interest in minimally invasive methods. Ultrasound (US)-guided percutaneous ablation is particularly attractive because it is a safe and relatively simple procedure. In this study, we investigated the results of US-guided percutaneous radiofrequency ablation (RFA) and partial nephrectomy (PN) in the treatment of cT1a renal cancers. Between August 2016 and February 2022, 271 patients with renal tumours underwent percutaneous RFA as initial treatment in our institution. In the same period, 396 patients with renal tumours underwent surgical tumour excision. For the purpose of this study, only patients with confirmed renal cancer with matched age and tumour characteristics (size, location) were selected for both groups. Thus, a group of 44 PN patients and 41 RFA patients were formed with the same qualification criteria for both groups. Parameters such as procedure length, blood loss, hospital stay, analgesics used, and pre- and post-procedural serum creatinine were compared between these groups. Patients followed up with contrast-enhanced CT. There was no significant difference in age, tumour size, tumour location, and creatinine levels between these groups. All procedures were generally well tolerated. During a median follow-up of 28 months, two cases of recurrence/residual disease were found in each group. The overall survival was 100% in both groups, and all patients were disease-free at the end of observation. Percutaneous RFA was associated with a significantly shorter procedure length and hospital stay, lower blood loss, and lower analgesics used than PN. In the selected group of renal cancer patients, US-guided percutaneous RFA was associated with a shorter hospital stay, less analgesics used, and a shorter procedure length than PN, without differences in the oncological results or kidney function.

Perioperative and Survival Outcomes of Patients Treated With Robot-Assisted Partial Nephrectomy and Percutaneous Microwave Ablation for Small Renal Masses: A Single Center Experience

BACKGROUND

Robot assisted partial nephrectomy (RAPN) and microwave ablation (MWA) are 2 of the most advanced techniques for the management of localized small renal masses.

PURPOSE

To compare the perioperative, functional and oncological results of RAPN and MWA.

MATERIALS AND METHODS

Data from 171 consecutive patients undergoing either RAPN or MWA for a localized small renal mass at a single academic center was retrospectively collected. Baseline features included patients' demographics and masses' characteristics. Procedures were compared in terms of perioperative outcomes and renal function variation Progression of a persistent lesion or local recurrence after a complete treatment defined local tumor progression. Descriptive statistics and survival analysis tested the association between predictors and local tumor progression.

RESULTS

Of all, 109 and 62 patients underwent RAPN and MWA. Patients in the MWA group were older (P = .002) had higher Charlson Comorbidity Index (CCI) (P < .001) and higher frequency of preoperative chronic kidney disease (P < .001). MWA led to a shorter postoperative hospitalization time (P < .001) and lower incidence of medical complications (6.5% vs. 22.9%, P = .02) than RAPN. GFR decline was similar between groups both at discharge (P = .39) and at the time of last follow up (P = 1.00). A lower rate of secondary interventions (11.7% vs. 2.8%, P = .037) and a better disease-free survival (83.2% vs. 96.5%, P = .027) were reported after RAPN. Conversely, cancer specific and overall survival were comparable (P > .05). At univariate regression analysis, MWA was associated with local tumor progression (HR 3.46, P = .040).

CONCLUSION

MWA displayed a lower perioperative impact, while functional outcomes were similar after each intervention. RAPN resulted superior in terms of tumor eradication, but no difference was noted regarding cancer specific survival. Thus, MWA represents a valid alternative in frail patients, though less radical than RAPN.

Percutaneous microwave ablation of T1a renal cell carcinomas: A 10-year single-center retrospective review

INTRODUCTION

Partial nephrectomy is currently the preferred treatment option for T1a renal cell carcinomas (RCC), with nephron-sparing techniques, including microwave ablation, becoming more common in select patients. Primary aims are to document outcomes of microwave ablation for T1a RCCs in an Australian tertiary centre to add to the evidence for its safety and efficacy.

METHODS

The prospectively maintained Sir Charles Gairdner Hospital Interventional Radiology database was retrospectively searched for all Renal Microwave ablations completed between June 2012 and February 2022. This database and a combination of hospital programmes including Agfa Impax PACS, Bossnet digital medical record and iSoft Clinical Manager were used to extract the relevant data which was anonymized and entered into an Excel spreadsheet for analysis.

RESULTS

Forty-eight patients underwent microwave ablation for 50 tumours. Of these, there were two local and two distant recurrences. A fifth patient had metastases on presentation. Higher local recurrence rates were associated with larger tumour size (P = 0.043). Tumour proximity to the collecting system <4 mm was associated with higher rates of complications (P = 0.020). RENAL scores did not show statistically significant correlation with complications (P = 0.092) or local or distant recurrence. Notably, the study follow-up time was longer than many comparative studies (mean = 2796, ~7.66 years censoring for death and mean = 832 days, ~2.28 years not censoring for death).

CONCLUSION

Consistent with the literature, this study further demonstrates that microwave ablation is a safe and efficacious option for treatment of T1a RCC.

Ablative Treatments for Small Renal Masses and Management of Recurrences: A Comprehensive Review

This review focuses on ablative techniques for small renal masses (SRMs), including radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA), and irreversible electroporation (IRE), and discusses recurrence management. Through an extensive literature review, we outline the procedures, outcomes, and follow-up strategies associated with each ablative method. The review provides a detailed examination of these techniques-RFA, CA, MWA, and IRE-elucidating their respective outcomes. Recurrence rates vary among them, with RFA and CA showing comparable rates, MWA demonstrating favorable short-term results, and IRE exhibiting promise in experimental stages. For managing recurrences, various strategies are considered, including active surveillance, re-ablation, or salvage surgery. Surveillance is preferred post-RFA and post-CA, due to slow SRM growth, while re-ablation, particularly with RFA and CA, is deemed feasible without additional complications. Salvage surgery emerges as a viable option for larger or resistant tumors. While ablative techniques offer short-term results comparable to surgery, further research is essential to understand their long-term effects fully. Decisions concerning recurrence management should consider individual and tumor-specific factors. Imaging, notably contrast-enhanced ultrasounds, plays a pivotal role in assessing treatment success, emphasizing the necessity of a multidisciplinary approach for optimal outcomes. The lack of randomized trials highlights the need for further research.

Percutaneous ablation of renal tumors: Long-term outcomes

OBJECTIVE

To evaluate the long-term outcomes of renal tumor ablation, analyzing efficacy, long-term survival, and factors associated with complications and therapeutic success.

MATERIAL AND METHODS

We retrospectively reviewed 305 ablations (generally done with expandable electrodes) of 273 renal tumors between May 2005 and April 2019. We analyzed survival, primary and secondary efficacy, and complications according to various patient factors and tumor characteristics.

RESULTS

Mean blood creatinine was 1.14 mg/dL before treatment and 1.30 mg/dL after treatment (p < 0.0001). Complications were observed in 13.25% of the ablations, including major complications in in 4.97%. Complications were associated with age (p = 0.013) and tumor diameter (p < 0.0001). Primary efficacy was 96.28%. Incomplete ablation was more common in lesions measuring > 4 cm in diameter (p = 0.002). Secondary efficacy was 95.28%. The only factor associated with the risk of recurrence was the size of the tumor (p = 0.02). Overall survival was 95.26% at 1 year, 77.01% at 5 years, and 51.78% at 10 years, with no differences between patients with malignant and benign lesions. Mortality was higher in patients with creatinine >1 (p = 0.05) or ASA > 2 (p = 0.0001).

CONCLUSIONS

Percutaneous ablation is extremely efficacious for renal tumors; it improves the prognosis of renal carcinoma to the point where it does not differ from that of benign lesions. Complications are rare. Like survival, complications are associated with age and overall health status.

Percutaneous thermal ablation for cT1 renal mass in solitary kidney: A multicenter trifecta comparative analysis versus robot-assisted partial nephrectomy

INTRODUCTION

Renal cell carcinoma (RCC) in solitary kidney (SK) represents a challenging scenario. We sought to compare outcomes of robot-assisted partial nephrectomy (RAPN) versus percutaneous thermal ablation (PTA) in SK patients with renal tumors cT1.

MATERIALS AND METHODS

We performed a multicenter retrospective analysis of SK patients treated for RCC. The PTA group included cryoablation or radiofrequency ablation. We collected baseline characteristics, intraoperative, pathological, and post-operative data. We applied an arbitrary composite "trifecta" to assess surgical, functional, and oncological outcomes, only for malignant histology. RFS analysis was performed using the Kaplan-Meier method. Multivariable regression analysis was performed to determine independent predictors of "trifecta" achievement.

RESULTS

We included 198 SK patients (RAPN, n = 50; PTA n = 119). Mean clinical tumor size was not significantly different while R.E.N.A.L. score was higher for RAPN (p < 0.001). No differences in intra and major post-procedural complications. Recurrence rate was higher in PTA group but not statistically significant (p < 0.328). No difference in metastasis rate was found (p = 0.435). RFS was 96.1% in RAPN and 86.8% in PTA cohort (p = 0.003) while no difference in PFS was detected (p = 0.1). Trifecta was achieved in 72.5% of RAPN vs 77.3% of PTA (p = 0.481). Multivariable analysis has not detected predictors for Trifecta achievement.

CONCLUSION

PTA offers good outcomes in the management of SK patients with RCC. Compared with RAPN, it might carry a higher risk of recurrence; on the other hand, re-treatment is possible. Overall, PTA can be safely offered to treat SK patients presenting RCC. In general, it should be preferred in more frail patients to minimize the risk of complications.

Cost-effectiveness analysis: percutaneous microwave ablation vs robotic-assisted partial nephrectomy for small renal masses

PURPOSE

The majority of newly diagnosed renal tumors are masses < 4 cm in size with treatment options, including active surveillance, partial nephrectomy, and ablative therapies. The cost-effectiveness literature on the management of small renal masses (SRMs) does not account for recent advances in technology and improvements in technical expertise. We aim to perform a cost-effectiveness analysis for percutaneous microwave ablation (MWA) and robotic-assisted partial nephrectomy (RA-PN) for the treatment of SRMs.

METHODS

We created a decision analytic Markov model depicting management of the SRM incorporating costs, health utilities, and probabilities of complications and recurrence as model inputs using TreeAge. A willingness to pay (WTP) threshold of $100,000 and a lifetime horizon were used. Probabilistic and one-way sensitivity analyses were performed.

RESULTS

Percutaneous MWA was the preferred treatment modality. MWA dominated RA-PN, meaning it resulted in more quality-adjusted life years (QALYs) at a lower cost. Cost-effectiveness analysis revealed a negative Incremental Cost-Effectiveness Ratio (ICER), indicating dominance of MWA. The model revealed MWA had a mean cost of $8,507 and 12.51 QALYs. RA-PN had a mean cost of $21,521 and 12.43 QALYs. Relative preference of MWA was robust to sensitivity analysis of all other variables. Patient starting age and cost of RA-PN had the most dramatic impact on ICER.

CONCLUSION

MWA is more cost-effective for the treatment of SRM when compared with RA-PN and accounting for complication and recurrence risk.

The Role of Focal Therapy and Active Surveillance for Small Renal Mass Therapy

Small and low-grade renal cell carcinomas have little potential for metastasis and disease-related mortality. As a consequence, the main problem remains the use of appropriately tailored treatment for each individual patient. Surgery still remains the gold standard, but many clinicians are questioning this approach and present the advantages of focal therapy. The choice of treatment regimen remains a matter of debate. This article summarizes the current treatment options in the management of small renal masses.

Applications of Focused Ultrasound in the Treatment of Genitourinary Cancers

Simple Summary

Cancer is a prevalent disease globally, and conventional treatment options have been associated with substantial morbidity for patients. The unique acoustic properties and biological effects of focused ultrasound have been investigated for use as an alternative treatment option for various forms of cancer with lower associated morbidity than standard treatments. The objective of our review was to assess the current state and various applications of focused ultrasound for the treatment of genitourinary cancers, including prostate, kidney, bladder, penile, and testicular malignancies. Current research demonstrates that focused ultrasound-based focal therapy shows promise for the treatment of localized prostate and kidney cancer, and the effect of ultrasound on cell membranes may increase the efficacy of chemotherapeutics and radiotherapy. Focused ultrasound-based treatment modalities should continue to be investigated as an alternative or complementary treatment option for cancer patients.

Abstract

Traditional cancer treatments have been associated with substantial morbidity for patients. Focused ultrasound offers a novel modality for the treatment of various forms of cancer which may offer effective oncological control and low morbidity. We performed a review of PubMed articles assessing the current applications of focused ultrasound in the treatment of genitourinary cancers, including prostate, kidney, bladder, penile, and testicular cancer. Current research indicates that high-intensity focused ultrasound (HIFU) focal therapy offers effective short-term oncologic control of localized prostate and kidney cancer with lower associated morbidity than radical surgery. In addition, studies in mice have demonstrated that focused ultrasound treatment increases the accuracy of chemotherapeutic drug delivery, the efficacy of drug uptake, and cytotoxic effects within targeted cancer cells. Ultrasound-based therapy shows promise for the treatment of genitourinary cancers. Further research should continue to investigate focused ultrasound as an alternative cancer treatment option or as a complement to increase the efficacy of conventional treatments such as chemotherapy and radiotherapy.

piRNAs and PIWI Proteins as Diagnostic and Prognostic Markers of Genitourinary Cancers

piRNAs (PIWI-interacting RNAs) are small non-coding RNAs capable of regulation of transposon and gene expression. piRNAs utilise multiple mechanisms to affect gene expression, which makes them potentially more powerful regulators than microRNAs. The mechanisms by which piRNAs regulate transposon and gene expression include DNA methylation, histone modifications, and mRNA degradation. Genitourinary cancers (GC) are a large group of neoplasms that differ by their incidence, clinical course, biology, and prognosis for patients. Regardless of the GC type, metastatic disease remains a key therapeutic challenge, largely affecting patients’ survival rates. Recent studies indicate that piRNAs could serve as potentially useful biomarkers allowing for early cancer detection and therapeutic interventions at the stage of non-advanced tumour, improving patient’s outcomes. Furthermore, studies in prostate cancer show that piRNAs contribute to cancer progression by affecting key oncogenic pathways such as PI3K/AKT. Here, we discuss recent findings on biogenesis, mechanisms of action and the role of piRNAs and the associated PIWI proteins in GC. We also present tools that may be useful for studies on the functioning of piRNAs in cancers.

Percutaneous radiofrequency for the treatment of small renal masses: Analysis of outcomes and complications after 10 years of experience

INTRODUCTION AND OBJECTIVE

The management of renal tumors ≤ 4 cm in elderly population or patients with comorbidities is a challenge, for which ablative therapies are an interesting alternative. The objective is to evaluate in our center the role of percutaneous radiofrequency in the treatment of small renal masses, the associated complications and the results obtained.

MATERIAL AND METHODS

Retrospective evaluation of the radiofrequency treatments carried out between April 2010 and April 2020 in our center. Demographic data, associated comorbidities, tumor characteristics, complications and oncological and functional outcomes were reviewed.

RESULTS

Fifty-seven tumors were treated in 53 patients. Mean follow-up of 48.2 months. The percentage of complete ablations obtained was of 89.5%. There were 19.3% of complications. According to Clavien-Dindo and SIR classification systems, 3.5% and 5.3% were major complications. A statistically significant association was found between the initial result of ablation and age (p = 0.047), RENAL-m (p = 0.044), the presence of cystic component (p = 0.049) and tumor size (p = 0.01). The cut-off point for size was established at 25 mm (p = 0.012). In multivariate analysis, only size remained as a predictor of initial ablation result (p = 0.01; OR 1.183; CI 95% 1.041-1.345). Cancer-specific survival and 5-year recurrence-free survival were 98.1% and 89.5%, respectively. A mean decrease of MDRD-4 of 6.59 mL/min (p = 0.005) was observed in the first six months after RFA.

CONCLUSIONS

Given the excellent oncological and functional results demonstrated, ultrasound-guided percutaneous radiofrequency ablation is an effective and safe treatment for small renal masses in selected patients.

Percutaneous thermoablation of small renal masses (T1a) in surgical candidate patients: oncologic outcomes

OBJECTIVE

To evaluate the local tumour progression-free survival (LTPFS), metastasis-free survival (MFS), cancer-specific survival (CSS) and overall survival (OS) of healthy surgical candidates who underwent percutaneous thermoablation (TA) as a first-line therapy for small renal masses (T1a).

METHODS

The institutional review board approved this bi-institutional retrospective study of 85 consecutive surgical candidates with 97 biopsy-proven malignant renal masses (T1a) treated with percutaneous TA from 2008 to 2016. The LTPFS, MFS, CSS and OS rates were calculated using the Kaplan-Meier method. Descriptive analysis was also performed.

RESULTS

The median tumour size was 2.3 cm (range, 0.7-3.9 cm). The minimal and mean follow-up periods were 24 and 56 months, respectively. Local recurrence was detected in four patients (4.7%) at 8.5, 13.8, 58.0 and 64.0 months of follow-up and retreated successfully with percutaneous TA. No patient developed metastatic renal cell carcinoma, and none died due to renal oncologic complications. One patient died of heart attack. The 5-year LTPFS, OS, MFS and CSS rates were 93.0%, 98.4%, 100% and 100%, respectively. Only two patients (2.3%) had major complications (Clavien-Dindo grade > II), including ureteropelvic junction stenosis and urinary obstruction due to ureteral blood clots.

CONCLUSIONS

Our study demonstrates that percutaneous TA is a feasible and effective first-line therapy for healthy surgical candidates with small renal masses (T1a). The 5-year LTPFS, OS, CSS and MFS rates were 93.0%, 98.4%, 100% and 100%, respectively, with a major complication rate of only 2.3%.

KEY POINTS

• Image-guided percutaneous thermoablation of small renal malignancies was effective in 95.3% of the healthy surgical candidates. • Major complications were detected in 2.3% of the patients. • The local tumour progression-free survival rate was 97.6% and 93.0% at 3 and 5 years, respectively.

Percutaneous tumor ablation versus partial nephrectomy for small renal mass: the impact of histologic variant and tumor size

BACKGROUND

The aim, of this study was to investigate recurrence rates in patients with T1 renal cell carcinoma (RCC) undergone partial nephrectomy (PN), radiofrequency ablation (RFA) or cryoablation (Cryo).

METHODS

We retrospectively evaluated data from 665 (81.4%), 68 (8.3%) and 83 (10.3%) patients who underwent PN, RFA and Cryo, respectively. Kaplan-Meier curves depict recurrence-free survival (RFS) rates in the overall population and after stratifying according to tumor's histology (namely, clear cell RCC and non-clear RCC) and size (namely <2 cm and 2-4 cm). Multivariable Cox regression model was used to identify predictors of recurrence. Cumulative-incidence plots evaluated disease recurrence and other causes of mortality (OCM).

RESULTS

Patients referred to PN experienced higher RFS rate compared to those treated with RFA and Cryo at 60-month in the overall population (96.4% vs. 79.4% vs. 87.8%), in patients with clear cell RCC (93.3% vs. 75% vs. 80.4%) and in those with tumor of 2-4 cm (97.3% vs. 78% and 84.4%; all P≤0.01). In patients with non-clear cell RCC and with tumor <2cm, PN showed higher RFS rate at 60-month as compared to RFA (97.9% vs. 84.4% and 95.1% vs. 78.1%, respectively: all P≤0.02). At multi-variate analysis, ablative techniques (RFA [HR=4.03] and Cryo [HR=3.86]) were independent predictors of recurrence (all P<0.03). At competing risks analysis, recurrence rate and OCM were 7.3% and 1.3% vs. 25% and 7.2% vs. 19.9% and 19.9% for PN, RFA and Cryo, respectively.

CONCLUSIONS

PN and Cryo showed similar RFS rates in patients with non-clear cell RCC and with renal mass <2cm.

Robotic-assisted Partial Nephrectomy for "Very Small" (<2 cm) Renal Mass: Results of a Multicenter Contemporary Cohort

BACKGROUND

Patient with "very small" (<2 cm) renal mass can be offered active surveillance, thermal ablation, or partial nephrectomy. The management strategy will consider patient preferences and prioritize potential harms associated with each of these options. To date, outcomes of robot-assisted partial nephrectomy (RAPN) in patients with "very small" renal masses have not been reported.

OBJECTIVE

To assess the outcomes of RAPN among patients with "very small" renal masses.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective analysis of a multi-institutional database including RAPN cases performed at eight high-volume US and European centers between 2009 and 2019. Patients were stratified into two groups according to clinical tumor size: <2 cm ("very small" renal mass, study group) and 2-4 cm (control group).

INTERVENTION

RAPN for renal masses.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Baseline characteristics and intraoperative, pathological, and postoperative data were compared between the study and the control group. A "trifecta" was used as surrogate of "surgical quality."

RESULTS AND LIMITATIONS

Overall, a total of 1019 patients were included in the analysis. Of these, 352 had a renal mass of <2 cm (34.5%) and 667 (65.5%) had a renal mass of 2-4 cm. At baseline, the study group presented a lower rate of chronic kidney disease ≥stage III (p < 0.001), a lower RENAL score (p = 0.001), and lower rates of hilar (p = 0.04) and endophytic (p = 0.02) masses. Warm ischemia time was shorter for the study group (median 14 vs 18 min, p < 0.001), which also showed a lower rate of overall postoperative complications (9.6% vs 14.7%, p < 0.001) and no major complications. In terms of oncological outcomes, three and ten patients developed a local recurrence in the study and the control group, respectively (p = 0.1). In the study group, higher estimated glomerular filtration rates were found at discharge (p = 0.001) and at the last follow-up (p = 0.007), which showed a "trifecta" achievement of 90.6%. The retrospective design may limit the generalizability of the findings.

CONCLUSIONS

Whenever an active treatment is indicated or warranted, RAPN represents a minimally invasive management option for "very small" renal masses, as it carries minimal risk of complications and has minimal impact on renal function. While both active surveillance and kidney ablation remain valid management options in these cases, RAPN can be offered and discussed with patients as it provides excellent outcomes with low morbidity.

PATIENT SUMMARY

In this report, we observed that robot-assisted partial nephrectomy represents a true minimally invasive active treatment for "very small" renal masses (<2 cm), as it carries minimal risk of complications and has minimal impact on renal function.

Is percutaneous image-guided renal tumour ablation ready for prime time?

In the last few decades, thermal ablation (TA) techniques have been increasingly applied to treat small localised renal cell carcinomas. Despite this trend, there is still an underuse of TA compared to surgery and a substantial lack of high-quality evidence derived from large, prospective, randomised controlled trials comparing the long-term oncologic outcomes of TA and surgery. Therefore, in this narrative review, we assess published guidelines and recent literature concerning the diagnosis and management of kidney-confined renal cell carcinoma to understand whether percutaneous image-guided TA is ready to be proposed as a first-line treatment.

Predicting positive surgical margins in partial nephrectomy: A prospective multicentre observational study (the RECORd 2 project)

PURPOSE

to evaluate clinical predictors of positive surgical margins (PSMs) in a large multicenter prospective observational study and to develop a clinic nomogram to predict the likelihood of PSMs after partial nephrectomy (PN).

MATERIALS AND METHODS

We prospectively evaluated 4308 patients who had surgical treatment for renal tumors between January 2013 and December 2016 at 26 urological Italian Centers (RECORd 2 project). Two multivariable logistic models were evaluated to predict the likelihood of PSMs. Center caseload was dichotomized using a visual assessment adjusted for several predictors of PSMs. A nomogram predicting PSMs was developed.

RESULTS

Overall, 2076 patients treated with PN were evaluated. pT1a, pT1b, pT2 and pT3a were recorded in 68.7%, 22.6%, 2.1% and 6.6% of the patients, respectively. PSMs were recorded in 342 (16.5%) patients. From a null multivariable model against number of PN/year, 60 PN/year were identified as the best cut-off to define a high-volume centre. At multivariable analysis, clinical stage (cT1a vs. cT2 [OR 1.94]; p = 0.03), volume centre (≤60 PN/year) (OR 2.22; p < 0.0001), imperative vs elective indication (OR 2.10; p = 0.04), surgical technique (laparoscopic vs. open [OR 1.62; p = 0.002), lymphovascular invasion (OR 2.27; p = 0.01) and upstaging to pT3a (OR 2.81; p < 0.0001) were independent predictors of PSMs. The final nomogram included age, ASA score, Charlson score, clinical tumor stage, surgical indication, surgical approach, surgical technique, PADUA score, clamp procedure and volume centre.

CONCLUSIONS

PSMs after PN were significantly more likely in patients with lower clinical stage, higher PADUA score, in individuals referred to laparoscopic PN and in those treated at lower volume centers. We used these data to develop a nomogram to predict such risk.