Stage T1a Renal Cell Carcinoma Research Articles

Other-Cause Mortality, According to Partial vs. Radical Nephrectomy: Age and Stage Analyses

IntroductionWe tested the association between other-cause mortality and partial vs. radical nephrectomy in patients with T1a, T1b, and T2 renal cell carcinoma, across all patient ages. Material and MethodsWithin the Surveillance, Epidemiology, and End Results database (2010-2020), patients with localized renal cell carcinoma stages (T1a-T1b-T2, N0, M0), who underwent partial or radical nephrectomy were identified. Only patients with tumor size 2 to 10 cm were included. Cumulative incidence plots and multivariable competing risks regression models were used. ResultsOf 68,195 patients, 28,845 (42%) underwent partial nephrectomy vs. 39,350 (58%) radical nephrectomy. In T1a patients, 5-year other-cause mortality rates were 6% for partial nephrectomy vs. 11% for radical nephrectomy (Δ=5%). In T1a patients, partial nephrectomy independently predicted lower other-cause mortality, across all ages (HR: 0.73, P < .001). In age category subgroup analyses addressing T1a patients, in all age categories, partial nephrectomy invariably predicted lower other-cause mortality than radical nephrectomy: ≤59 years (HR: 0.67, P < .001); 60 to 69 years (HR: 0.70, P < .001); and ≥70 years (HR: 0.79, P < .001). Finally, in T1b patients, as well as in T2 patients, no other-cause mortality advantage was recorded for partial vs. radical nephrectomy: T1b (8 vs. 10%, Δ=2%); T2 (8 vs. 9%, Δ=1%). ConclusionsRelative to radical nephrectomy, partial nephrectomy is associated with lower other-cause mortality in stage T1a renal cell carcinoma patients across all age categories, including the oldest patients. Conversely, no clinically meaningful other-cause mortality benefit was associated with partial nephrectomy in stages T1b or T2, regardless of age, including youngest patients.

Usefulness of renal nephrometry scoring systems in the prediction of complications associated to percutaneous image-guided treatment for small renal masses

IntroductionDue to their increasing prevalence and complex management, renal tumors are challenging for health professionals. The study aims to evaluate the usefulness of R.E.N.A.L. and PADUA nephrometry scores in the prediction of complications after percutaneous cryoablation. Material and methodsThe study prospectively analyzed 90 patients with 101 stage T1a renal cell carcinoma (RCC) tumors treated with cryoablation. ResultsNinety patients with 101 small renal tumors who received cryoablative therapy were investigated. The mean age of the patients was 68 years and 74.4% were male. Most tumors were smaller than 4 cm (89.1%) and the mean PADUA and R.E.N.A.L. scores were 8.65 and 7.35, respectively. Complications were observed in 12 cases. PADUA and R.E.N.A.L. scores demonstrated moderate predictive power (AUC = 0.58 and AUC = 0.63, respectively) for post-cryoablation complications. ConclusionsPercutaneous cryoablation is a safe and effective treatment for small renal tumors. The R.E.N.A.L. and PADUA renal nephrometry scores have moderate predictive power for complications associated with percutaneous cryoablation of renal tumors.

Impacto de los sistemas de nefrometría renal en la valoración de las complicaciones en el tratamiento percutáneo guiado por imagen de las masas renales de pequeño tamaño

IntroductionDue to their increasing prevalence and complex management, renal tumors are challenging for health professionals. The study aims to evaluate the usefulness of R.E.N.A.L. and PADUA nephrometry scores in the prediction of complications after percutaneous cryoablation. Material and methodsThe study prospectively analyzed 90 patients with 101 stage T1a renal cell carcinoma (RCC) tumors treated with cryoablation. ResultsNinety patients with 101 small renal tumors who received cryoablative therapy were investigated. The mean age of the patients was 68 years and 74.4% were male. Most tumors were smaller than 4 cm (89.1%) and the mean PADUA and R.E.N.A.L. scores were 8.65 and 7.35, respectively. Complications were observed in 12 cases. PADUA and R.E.N.A.L. scores demonstrated moderate predictive power (AUC = 0.58 and AUC = 0.63, respectively) for post-cryoablation complications. ConclusionsPercutaneous cryoablation is a safe and effective treatment for small renal tumors. The R.E.N.A.L. and PADUA renal nephrometry scores have moderate predictive power for complications associated with percutaneous cryoablation of renal tumors.

Renal Abscess Complicated by Renal Vein Thrombosis Mimicking Clinical Stage T3a Renal Cell Carcinoma

Renal abscesses accompanied by a renal vein thrombosis (RVT) may have a similar appearance to clinical stage T3a renal cell carcinoma (RCC) on computed tomography (CT) imaging. RVTs are rare clinical findings that more commonly occur in adults with malignant renal tumors or nephrotic syndrome. A 71-year-old woman with risk factors for both renal infection and RCC was found to have a heterogeneous mass with irregular borders and areas of contrast enhancement on CT imaging. A two-week course of antibiotic and anti-coagulant treatment was prescribed with close follow-up. Urine culture eventually grew greater than 100,000 colonies of Escherichia coli. Repeat imaging after six weeks revealed resolution of the mass and the RVT. This patient's case emphasizes that although the findings of RVT and renal mass more commonly point to the diagnosis of malignancy, infections many present in a similar manner but require substantially different treatment. Close follow-up with repeat imaging is imperative to differentiate malignancy from infection or other causes.

Histopathologic features and parameters predicting recurrence potential of small renal masses

Abstract Background Small renal masses (SRMs) are defined as contrast-enhanced masses with a diameter of ≤4 cm, usually consistent with clinical stage T1a renal cell carcinoma (RCC). This study aimed to explore the histopathological features of a contemporary series of SRMs and investigate parameters that could predict their pathological nature, metastatic potential, and recurrence potential. Materials and methods Small renal masses were identified in 166 of 427 patients who underwent surgery for suspected RCC. The radical nephrectomy/partial nephrectomy ratio was 1:44, and autotransplantation was performed in a single case. Variables associated with metastatic recurrence of SRM were analyzed using χ2 and logistic regression models. Results Renal cell carcinoma was confirmed in 86% (n = 143) of cases, whereas benign tumors were present in 14% (n = 23) of cases. Seventeen percent of the RCC cases were high-grade (Fuhrman G3–4). Among SRMs with a diameter of &gt;2 cm, 71% were malignant. The mean ± standard deviation diameter of the removed SRMs was 28 ± 12 mm, significantly higher in the malignant SRMs group (31 ± 8 vs. 24 ± 9 mm) (p = 0.005). During follow-up, local recurrence was identified in 4 patients versus new distant metastasis in 11 patients. Metastatic lesions were detected in the lungs (1.8%), bone (1.2%), distant (1.9%) and regional lymph nodes (1.2%), liver (0.6%), and multiple organs (2.4%). Patients with malignant SRMs were significantly older than those with benign tumors (p = 0.036). The multivariate analysis identified tumor size, Fuhrman grade, stage, nodal and distant metastasis status, tumor localization, and treatment modality as characteristics significant for tumor recurrence. Conclusions The majority of treated neoplasms were malignant, but their incidence was low among SRMs with a diameter of &lt;2 cm. Our results emphasized the importance of histopathological features and treatment modalities in predicting malignant recurrence.

Survival benefit stratification of partial nephrectomy versus non-surgical treatment in elderly patients with T1a renal cell carcinoma.

Renal cell carcinoma (RCC) of stage T1a has been proven to be of low-grade malignancy and mostly affects elderly individuals with relatively limited life expectancy. However, research on the survival benefit of surgery relative to non-surgical treatment (NST) is limited. The aim of the study was to investigate the survival difference between partial nephrectomy (PN) and NST and to establish a benefit stratification model for elderly patients (≥70 years) diagnosed with T1a RCC. Patients diagnosed with non-metastatic T1a RCC who received PN or NST were identified from the SEER database during 2004-2015. Before survival analysis, propensity score matching (PSM) was performed. Overall survival (OS) was estimated by the Kaplan-Meier method, and subgroup analyses were used to identify favorable factors of PN. Independent factors of survival were recognized by multivariate Cox regression analysis. Patients diagnosed with non-metastatic T1a RCC who received PN or NST were identified from the SEER database during 2004-2015. Before survival analysis, propensity score matching (PSM) was performed. Overall survival (OS) was estimated by the Kaplan-Meier method, and subgroup analyses were used to identify favorable factors of PN. Independent factors of survival were recognized by multivariate Cox regression analysis. Our findings suggest that the survival benefit of PN could be stratified based on the clinical characteristics in patients with stage T1a RCC aged 70 years or older, which may help physicians and patients optimize clinical decisions.

Tips and Tricks for Successful Percutaneous Cryoablation of Large Renal Cell Carcinomas.

Percutaneous cryoablation has proved to be safe and effective for the treatment of stage T1a renal cell carcinoma (RCC). Patients with larger-sized RCCs may not be good surgical candidates or may have tumors located in anatomically unfavorable locations, which makes partial nephrectomy more challenging. In this patient population, percutaneous cryoablation can be considered a treatment option, given its less invasive nature when compared to surgery. The ablation of larger-sized RCCs requires careful planning to ensure that the tumor volume is completely covered within the ablation zone, while minimizing the risks of non-target injury to the surrounding critical organs. In this article, we share our institutional experience in treating larger-sized RCCs (> 4 cm) using percutaneous cryoablation alone. We discuss strategies to maximize the volume of the ablation zone through the precise placement of the probes. We also shed light on different techniques to protect the surrounding structures during cryoablation.

Radiofrequency ablation using real-time ultrasonography-computed tomography fusion imaging improves treatment outcomes for T1a renal cell carcinoma: Comparison with laparoscopic partial nephrectomy.

PurposeTo determine whether real-time ultrasonography–computed tomography (US-CT) fusion imaging can improve technical feasibility versus B-mode US and provide comparable outcomes of radiofrequency ablation (RFA) for T1a renal cell carcinoma (RCC) compared with laparoscopic partial nephrectomy (LPN).Materials and MethodsBetween June 2013 and August 2016, biopsy- or pathologically confirmed stage T1a RCCs were retrospectively reviewed. Of these, 39 cases were included in the RFA group, and 46 cases were included in the LPN group. In the RFA group, we evaluated tumor visibility and technical feasibility before RFA on a four-point scale on B-mode US and US-CT fusion images. After RFA, hospital days, creatinine value, complications, and disease-free survival rate were compared between the two groups. All results were analyzed by use of the Mann–Whitney U-test and Kaplan–Meier method.ResultsCompared with B-mode US alone, real-time US-CT fusion significantly improved the tumor visibility score and overall mean technical feasibility grade (p<0.001). The 5-year disease-free survival rate was 97.4% and 97.8% in the RFA and LPN groups, respectively, and there was no statistically significant difference between groups (p=0.1). Mean periprocedural creatinine levels were significantly lower in the RFA group than in the LPN group. The number of hospital days was shorter in the RFA group. Minor complications were present in 5.1% of the RFA group and 13.0% of the LPN group, with no major complications.ConclusionsUS-CT fusion-image-guided RFA improved tumor visibility scores and overall mean technical validity and resulted in a comparable disease-free survival rate to LPN.

Efficacy and safety of CT-guided microwave ablation for stage T1a renal cell carcinoma in patients with a solitary kidney

Objective To retrospectively evaluate early clinical outcomes of percutaneous microwave ablation (MWA) for stage T1a renal cell carcinomas (RCCs) in solitary kidney patients. Materials and methods 15 solitary kidney patients with 16 stage T1a N0M0 biopsy-proved RCCs underwent CT-guided percutaneous microwave ablation between October 2016 and July 2020. The patients were followed up with contrast-enhanced computed tomography or magnetic resonance imaging at 1, 3, and 6 months and every 6 months thereafter. Serum creatinine levels of each patient pre MWA, 1 day after MWA and the most recent record were collected. Technical effectiveness, local recurrence, survival rates and complications were accessed. Results Complete ablation was achieved in all 16 tumors (100%) including 13 clear cell carcinomas and 3 papillary carcinomas. Within the follow-up time (median: 24 months) no tumor recurrence or major complication was detected. No significant change in serum creatinine level was noted. The cancer-specific survival rate was 100% (15 of 15), and 1-, 2-, and 3-year overall survival rates were 100%, 93.3%, and 93.3%, respectively. Conclusion Percutaneous MWA is an effective and safe treatment option for stage T1a RCCs in solitary kidney patients; it can achieve high complete ablation rate in selected lesions of appropriate size and location.

Prognostic Evaluation of the Site of Invasion in Pathological Stage T3a Renal Cell Carcinoma.

To investigate the prognostic values of fat invasion (FI) and renal vein invasion (RVI) in pT3a renal cell carcinoma (RCC), as single factors or concomitant presence. We retrospectively reviewed the data of 173 patients who underwent radical or partial nephrectomy for RCC in our Institution. At a median follow-up time of 48 months, patients with RVI showed significantly increased risk of disease recurrence and worse cancer-specific survival (CSS) when compared to those with FI (p=0.007, p=0.022, respectively). Having combined RVI and FI did not show inferior prognosis compared to those with RVI only. In multivariable analysis, RVI was an independent factor for disease recurrence (HR=2.06, 95% CI=1.10-3.87, p=0.024) and CSS (HR=2.46, 95% CI=1.01-6.0, p=0.048). For patients with T3a renal tumors, RVI was associated with inferior prognosis compared to those with FI.

Abstract No. 602 Burn or freeze: meta-analysis comparing microwave versus cryoablation in the treatment of T1a renal masses

To compare the outcomes of microwave ablation (MWA) vs. cryoablation (CA) for T1a renal masses. A review of literature for studies from MEDLINE and EMBASE from 2005 to 2019 was performed without language restrictions. Inclusion criteria were 1- stage T1a renal cell carcinoma (RCC), 2- use of CA or MWA percutaneously, 3- case series or retrospective studies with >15 patients and, 4- reported outcomes of local recurrence, overall survival (OS) and complications. When available, complications were quantified for MWA and CA for each study. When recurrence rates or complication rates or OS were not included in a study, that study population was not included in the relevant calculations. Studies with overlapping populations were excluded. The analysis was carried SPSS software. For categorical variables, counts or proportions were extracted from each study and merged. For continuous variables means and standard deviations were extracted and merged. We used the chi-square test for analyzing baseline characteristics of patients. Complications and recurrences were calculated as odds ratios with 95% confidence intervals. A test of heterogeneity of included studies was conducted, sensitivity analysis and publications bias were also done. A total of 29 studies (12 MWA and 17 CA) met the inclusion criteria with overall 3763 patients (3139 patients in CA and 624 patients in MWA). The pooled proportion of patients for recurrence was 1270 patients (898patients in CA and 372 patients in MWA) and 1523 patients for complications (1106 CA and 417 MWA). For 2-year OS, 2054 patients were included in analysis (1932 for CA and 122 for MWA). In the pooled results, complication rates were not statistically significantly different between CA (11.8%) and MWA (12.0%) (OR: 0.99 95% CI = 0.705-1.410 P = 0.876). The local recurrence rate was 10.5% for CA vs. 5.9% for MWA which was statistically significant (OR: 0.53 95%CI = 0.332-0.870 P = 0.01). There was a difference in 2 years OS between CA (73%) versus MWA (93.4%) (OR: 0.19 95% CI: 0.092-0.393 P = 0.0001). In our meta-analysis, MWA and CA did not show a difference in complications, but local recurrence was lower with MWA and 2-year survival was better.

Trends in Percutaneous Thermal Ablation Therapies in the Treatment of T1a Renal Cell Carcinomas Rather than Partial Nephrectomy/Radical Nephrectomy.

With the increased incidence of stage T1a renal cell carcinoma (RCC) has come the recognition that these lesions tend to be low grade and slow growing, with low probability of metastasis not necessarily requiring surgery. As alternatives to surgery, both active surveillance and ablation have been advocated for the management of selected patients with stage T1a renal cancers due to slow rate of tumor growth and low metastatic potential based on recent epidemiological studies. Thermal ablation also has consistently reported favorable complication and renal preservation rates compared with surgical approaches. However, most studies are single-center case series and meta-analysis of these series and comparative prospective series with long-term follow-up are lacking. The purpose of this article is to review the principal thermal ablation modalities and oncological outcomes for the treatment of stage T1 RCCs with long-term follow-up.

Re: Outcomes of Pathologic Stage T3a Renal Cell Carcinoma Up-Staged from Small Renal Tumor: .

Re: Outcomes of Pathologic Stage T3a Renal Cell Carcinoma Up-Staged from Small Renal Tumor: .

Age at diagnosis and the surgical management of small renal carcinomas: findings from a cross-sectional population-based study.

To describe the use of partial nephrectomy (PN) for patients with stage T1a renal cell carcinoma (RCC) by age group (<65 and ≥65years) in two Australian states. All adults diagnosed with RCC in 2012 and 2013 were identified through population-based cancer registries in the Australian states of Queensland and Victoria. For each patient, research assistants extracted patient, tumour and treatment data from medical records. Percentages of patients treated by PN were determined for the two age groups. Multivariable logistic regression analyses examined factors associated with PN. Clinicians treating RCC were sent surveys to assess attitudes towards PN. Data were collected on 956 patients (Victoria: n = 548; Queensland: n = 404) with stage T1a RCC. Of those undergoing surgery (n = 865), PN was more common for those aged <65 years (61%) than for those aged ≥65years (44%), with this difference significant after adjusting for patient, tumour (odds ratio 0.50, 95% confidence interval 0.36-0.70). There were significant interactions between age and treatment centre volume (P < 0.05) and residential state (P < 0.05). PN was less likely for younger patients treated at lower-volume hospitals (<24 patients a year) but hospital volume was not associated with PN for older patients. PN was less likely for older patients in Queensland than Victoria. In multivariable analyses, age was not related to laparoscopic surgery. Queensland clinicians were less likely than those from Victoria to agree that PN was the treatment of choice for most T1aN0M0 tumours (P < 0.001). In Australia, patients aged > 65years with small renal cancers were less likely to be treated by PN than younger patients. The variation in the surgical procedure used to treat older T1a RCC patients by state and hospital volume indicates that better evidence is needed to direct practice in this area.

Local anesthesia for ultrasound-guided percutaneous cryoablation of renal cell carcinoma

Background. There is a category of patients with renal masses, due to severe concomitant diseases, can not perform the operation or may be associated with a threat to life. In addition, many patients with small tumor sites are extremely concerned about their disease and are negative about the tactics of active observation and insist on treatment. These patients can be offered alternative methods of treatment of renal cell carcinoma (RCC), the leading of which is cryoablation.Objective: to evaluate the effectiveness and safety of percutaneous cryoablation of the kidney tumor under ultrasound control.Materials and methods. In the Urology Clinic of the I.M. Sechenov First Moscow State Medical University during the period from 2015 to 2017 performed 23 percutaneous cryoablation of RCC, 7 (men – 4, women – 3) of which were performed under local anesthesia. In 4 patients due to severe concomitant diseases, general anesthesia was associated with an extremely high risk. Three patients refused from dynamic observation and from traditional surgical treatment; preferred an alternative treatment in the form of a percutaneous cryoablation under local anesthesia. In 4 cases, the formations were located in the lower segment along the posterior surface of the kidney, in 3 – along the lateral surface in the middle segment. The size of the formations was not used 4 cm (T1a). The age of the patients was 62.3 years (51 to 83 years). Right-sided localization of the tumor was noted in 3 patients, left-sided – in 4. One patient had a single kidney.At the preoperative stage and 6 months after the operation, all patients underwent ultrasound with dopplerography, multislice computerized tomography with contrast, and computer 3D modeling, which helped to clearly assess the size of the tumor, clarify the prevalence of the tumor process and the spatial ratio of the internal surface of the tumor node to the elements of the bowl-and-pelvis system. In all the observations, the formations were located along the posterior or lateral surface of the kidney; in the lower or middle segment; without invasion of the sine. We used a 3rd generation cryomash machine SeedNet gold (Galil Medical), cryoprobes IceSeed and IceRod. Intraoperative, immediately before cryoablation, a tumor biopsy was performed, the presence of RCC in all patients was confirmed morphologically.Results. According to the ultrasound examination with echodopplerography at 6 months after the operation, the size of the tumor node’s formations decreased on average by 6–8 mm, while there was no blood flow in them. When multislice computerized tomography with 3D modeling was performed, the formation was reduced and the accumulation of the contrast preparation was completely absent or their accumulation gradient did not exceed 10 HU (initially it was about 200 HU). There were no intraoperative complications. In 1 observation, a postoperative hematoma measuring 7 × 3 cm was resolved conservatively and did not require surgical treatment.Conclusions. Percutaneous cryodestruction under local anesthesia using ultrasound guidance seems to be an effective and safe technique for treating patients with stage T1a RCC with localization in the posterior or lateral surface in the lower or middle segments without invasion of the renal sinus and surrounding tissues. It is planned to continue monitoring patients to assess the long-term effectiveness of cryoablation.

Percutaneous Cryoablation of Solitary, Sporadic Renal Cell Carcinoma: Outcome Analysis Based on Clear-Cell versus Papillary Subtypes

PurposeTo evaluate treatment outcomes with percutaneous cryoablation (PCA) based on renal cell carcinoma (RCC) histology. Methods and MaterialsPatients treated with PCA for a solitary, sporadic stage T1a RCC from 2003 to 2016 were identified from a single institution’s renal ablation registry. Patients with multiple tumors, history of RCC, or genetic syndromes associated with RCC (n = 60); no specific RCC subtype determined from core biopsy (n = 66); RCC subtype other than clear-cell or papillary (n = 7); or less than 3 mo of follow-up imaging (n = 5) were excluded. In total, 173 patients met study inclusion criteria. Oncologic outcomes, clinical outcomes, and complications were evaluated based on tumor subtype. ResultsOf the 173 patients who underwent PCA for a stage T1a RCC, 130 (75%) had clear-cell RCC (ccRCC) and 43 (25%) had papillary RCC (pRCC). Median tumor size was 2.9 cm (range, 1.3–4.0 cm). Technically successful cryoablation was achieved in all 173 patients. Local tumor recurrence developed in 6 patients with ccRCC (4.6%), new renal tumors developed in 1 patient (0.8%), and metastatic RCC developed in 1 patient (0.8%) who also had local tumor recurrence. No patients with pRCC showed local tumor recurrence, new renal tumors, or metastatic disease. The 5-year disease-free survival rate in patients with ccRCC was 88%, compared with 100% in patients with pRCC (P = .48). Nine patients (5.2%), all with ccRCC, experienced major complications (P = .11). ConclusionsPercutaneous ablation is a viable treatment option for patients with clinical stage T1a pRCC and ccRCC. Percutaneous ablation may be a very favorable treatment strategy particularly for pRCC.

Local tumor progression after ultrasound-guided percutaneous microwave ablation of stage T1a renal cell carcinoma: risk factors analysis of 171 tumors

Purpose: To retrospectively review long-term oncologic outcomes after ultrasound (US)-guided percutaneous microwave ablation (MWA) of T1a renal cell carcinoma (RCC) and to identify the incidence and risk factors that predict local tumor progression (LTP) after MWA of RCC.Materials and methods: The present study was approved by the institutional review board. A total of 162 patients with 171 RCC nodules (mean size, 2.6 ± 0.8 cm; range, 0.6–4.0 cm) were treated by MWA between April 2006 and January 2017. The influence of eight factors (age; sex; longest tumor diameter; tumor number, location and pathology type; ablation power and time) affecting the risk of LTP was assessed. Univariate Kaplan–Meier and Cox proportional hazard models were used for statistical analysis.Results: LTP occurred in five patients (5 tumors) after US-guided percutaneous MWA of stage T1a RCC. The overall occurrence of LTP was 2.9% per tumor and 3.0% per patient with a median follow-up of 45.5 months. Among the 162 patients, there were no instances of LTP-related deaths; however, 20 patients died of other diseases. All patients with LTP survived through follow-up. The survival rate of LTP-free patients at 1, 3 and 5 years were 98.7%, 89.5% and 82.1%, respectively (p = .38). Univariate and multivariate analysis identified tumor location to be the only independent predictor of LTP.Conclusions: US-guided percutaneous MWA for T1a RCC achieved a relatively low LTP incidence rate. Tumors adjacent to the renal pelvis or bowel increased the potential of LTP occurrence.

Outcomes of pathologic stage T3a renal cell carcinoma up-staged from small renal tumor: emphasis on partial nephrectomy

BackgroundThe prognosis of patients with pathologic stage T3a renal cell carcinoma (RCC) that is up-staged from a small renal tumor remains controversial. We evaluated the prognosis of patients with RCC who were up-staged from clinical stage T1 to pathologic stage T3a.MethodsWe retrospectively reviewed the data of 3431 patients who were surgically treated for clinical stage T1 RCC. The survival outcomes were compared using Kaplan-Meier and Cox proportional analyses.ResultsAmong the clinical stage T1 patients, 215 (6.3%) were finally up-staged to pathologic stage T3a. Patient age (HR 1.302, 95% CI 1.018–1.046, p < 0.001), tumor diameter (HR 1.686, 95% CI 1.551–1.834, p < 0.001), and hilar location (HR 1.765, 95% CI 1.147–2.715, p = 0.010) were significantly associated with upstaging. Kaplan-Meier analyses showed significantly shorter recurrence-free, cancer-specific and overall survivals (all p < 0.001) in patients who were up-staged. Multivariate Cox analyses revealed pathologic upstaging as an independent predictor of shorter recurrence-free (HR 2.195, 95% CI 1.459–3.300, p < 0.001), cancer-specific (HR 2.238, 95% CI 1.252–4.003, p = 0.007), and overall survivals (HR 1.632, 95% CI 1.029–2.588, p = 0.037). Subgroup analysis of pathologic stage T3a showed no significant difference in survival of the partial nephrectomy group when compared to the radical nephrectomy group (all p > 0.5).ConclusionsPatients up-staged from clinical stage T1 to pathologic stage T3a RCC showed shorter survival outcomes than those without upstaging. However, partial nephrectomy, compared with radical nephrectomy, showed comparable outcomes in patients who were up-staged.

4:03 PM Abstract No. 247 Surveillance, Epidemiology, and End Results (SEER) survival study of stage T1a renal cell carcinoma treated with ablation vs. partial nephrectomy: a propensity-matched analysis

To analyze survival in stage T1a renal cell carcinoma (RCC) treated with ablation compared to partial nephrectomy, using the Surveillance, Epidemiology, and End Results (SEER) database. Using the SEER database, we identified cases of diagnosed RCC who underwent partial nephrectomy or ablation between 2004 and 2013. Patients were included if they had a mass <4 cm and had partial or subtotal nephrectomy. We excluded patients with tumor extension outside the kidney or any nodal or distant metastases. Descriptive statistics were performed with Chi-squared and Wilcoxon sum rank tests for categorical and continuous variables respectively. Kaplan-Meier (KM) statistic and cox proportional hazards regression (CR) were performed. Propensity score matching (matched by age, sex, race, grade, tumor size, and tumor extension) was used to reduce treatment-selection bias and match pairs of subjects with similar background variables. KM and CR analyses were repeated after propensity matching. A total of 4592 patients were included (809 receiving ablation and 3783 receiving partial nephrectomy). Patients who underwent ablation were more likely to be older, with larger tumors, and lower tumor grade. Before propensity matching, there was significantly better overall survival (OS) and cancer-specific survival (CSS) in the partial nephrectomy group (93.6% 5-year survival) compared to the ablation group (81.9% 5-year survival) with p<0.0001. Propensity matching generated 1222 matched pairs with similar background characteristics in all background variables. Again, there was better OS in the partial nephrectomy group (91.0% vs 86.3% 5-survival, p = 0.0457), but the curves are not as divergent as in the pooled cohort. However, there is no significant difference in CSS between the treatment groups (p = 0.4023) in the propensity matched cohort. In this propensity-matched population study of stage T1a RCC, partial nephrectomy offers slightly better OS but similar CSS compared with ablation.

Abstract No. 684 Imaging surveillance following radiofrequency ablation of renal cell carcinoma

The purpose of this study is to review our institution's ten-year experience with imaging surveillance following percutaneous radiofrequency ablation for spontaneous stage T1a renal cell carcinoma, and apply risk stratification based upon the post-procedure CT scan, modified renal nephrometry score, and tumor histology. All renal radiofrequency ablation procedures performed at our institution from 1/1/2005 through 7/31/2015 were reviewed, including pathology and follow-up imaging. Inclusion criteria were all cases of T1a biopsy-proven renal cell carcinoma with at least one follow-up imaging study after the post-ablation scan. Exclusion criteria were benign or indeterminate pathology, Von Hippel Lindau syndrome (VHL), no imaging follow-up available, prior thermal ablation on the same lesion, or RFA discontinued due to technical factors. Cases meeting inclusion criteria were evaluated with mRENAL Nephrometry score, tumor histology, and post-therapy CT scan. Time lag to detection was calculated for each instance of recurrence. 52 cases (in 49 patients) of T1a biopsy-proven renal cell carcinoma status post radiofrequency ablation with at least one follow-up imaging study met the criteria for inclusion. 7 cases of RCC recurrence were identified. Cases of disease recurrence had a statistically significantly higher mRENAL score (7.3 versus 6.0, two-tailed T-test p-value .0087). Recurrence was more likely in tumors with clear cell histology (5/18 versus 2/34 for other histology, Fisher exact test statistic value .0409). There were no cases of disease recurrence if the post-therapy CT scan was definitively negative. The mRENAL Nephrometry score, tumor histology, and post-therapy CT scan inform the rate of tumor recurrence following radiofrequency ablation of T1a renal cell carcinoma. These data may be incorporated into the development of surveillance strategies to yield cost savings and decrease patient radiation exposure, while maintaining surveillance effectiveness.Tabled 1Imaging Surveillance Following Radiofrequency Ablation of Renal Cell CarcinomaCharacteristics of RCC RecurrenceCase#Tumor size (cm)mRENAL scoreRCC histologyPost-RFA CTRFA to detection (days)Lag to detection (days)Size at detection (cm)Recurrence strategy13.58Clear cellIndeterminate11382433.5Surveillance23.18Clear cellNot performed76763.2Nephrectomy32.97Clear cellNot performed4584060.9Repeat RFA43.19Clear cellIndeterminate2382381.7Surveillance52.57Clear cellPositive110.3Surveillance62.77RCC NOSNot performed1861861.9Repeat RFA72.14PapillaryNot performed2712711.6Surveillance Open table in a new tab