Development of an Automatic Interpretation Algorithm for Uroflowmetry Results: Application of Artificial Intelligence / 대한배뇨장애요실금학회지

Purpose@#To develop an automatic interpretation system for uroflowmetry (UFM) results using machine learning (ML), a form of artificial intelligence (AI). @*Methods@#A prospectively collected 1,574 UFM results (1,031 males, 543 females) with voided volume>150 mL was labelled as normal, borderline, or abnormal by 3 urologists. If the 3 experts disagreed, the majority decision was accepted. Abnormality was defined as a condition in which a urologist judges from the UFM results that further evaluation is required and that the patient should visit a urology clinic. To develop the optimal automatic interpretation system, we applied 4 ML algorithms and 2 deep learning (DL) algorithms. ML models were trained with all UFM parameters. DL models were trained to digitally analyze 2-dimensional images of UFM curves. @*Results@#The automatic interpretation algorithm achieved a maximum accuracy of 88.9% in males and 90.8% in females when using 6 parameters: voided volume, maximum flow rate, time to maximal flow rate, average flow rate, flow time, and voiding time. In females, the DL models showed a dramatic improvement in accuracy over the other models, reaching 95.4% accuracy in the convolutional neural network model. The performance of the DL models in clinical discrimination was outstanding in both genders, with an area under the curve of up to 0.957 in males and 0.974 in females. @*Conclusions@#We developed an automatic interpretation algorithm for UFM results by training AI models using 6 key parameters and the shape of the curve; this algorithm agreed closely with the decisions of urology specialists.

Open Partial Nephrectomy vs. Robotassisted Partial Nephrectomy for a Renal Tumor Larger than 4 cm: a Propensity Score Matching Analysis

Background@#To compare open partial nephrectomy (OPN) and robot-assisted partial nephrectomy (RAPN) in the management of renal tumors larger than 4 cm. @*Methods@#Clinical records of 220 patients who underwent OPN or RAPN for a single renal tumor ≥ 4.0 cm with a normal contralateral kidney were reviewed. After determining the propensity score, surgical parameters, functional outcomes, and oncological outcomes were compared between OPN (n = 67) and RAPN (n = 67) groups of patients. @*Results@#The RAPN group had longer operation time (149.0 min vs. 173.3 min, P = 0.030) and longer ischemic time (20.3 min vs. 29.4 min, P = 0.001), but shorter hospital stay (8.2 days vs 6.0 days, P = 0.001) than the OPN group. Estimated blood loss (P = 0.053), pain visual analog score at 1 day postoperatively (P = 0.194), and complications of grade III or higher (P = 0.403) were similar between OPN and RAPN groups. There was no radical conversion or positive surgical margin in either group. Mean change in 6-month estimated glomerular filtration rate was significantly better in the RAPN group (−8.2 vs. −3.1, P = 0.027). There was no statistical difference in recurrence-free survival (P = 0.970) or cancer-specific survival (P = 0.345) between the two groups. @*Conclusion@#RAPN is a safe and feasible surgical modality comparable to OPN for managing renal tumors larger than 4 cm in terms of surgical, functional, and oncological outcomes.

A Novel Mobile Acoustic Uroflowmetry: Comparison With Contemporary Uroflowmetry / 대한배뇨장애요실금학회지

Purpose@#This study aimed to evaluate the accuracy and reliability of a new smartphone-based acoustic uroflowmetry compared to conventional uroflowmetry. @*Methods@#This was a prospective validation study enrolling 128 subjects from September 2017 to April 2018 comparing a novel acoustic uroflowmetry to conventional uroflowmetry in an outpatient urologic clinic at Seoul National University Bundang Hospital. Visual comparison of flow patterns and uroflow parameters such as maximum flow rate (Qmax), average flow rate (Qavg), and voided volume were compared between the 2 techniques. Reliability and accuracy of the uroflowmetry results were compared using Pearson correlation coefficient (PCC) and Student t-test, respectively. @*Results@#One hundred twelve participants were included in the study. Of these, 77 had baseline urologic comorbidities while 35 were normal participants. Flow patterns between the 2 uroflowmetry techniques demonstrated strong visual correlation. When compared to conventional uroflowmetry, all 3 parameters of voiding in male participants showed a very robust correlation with PCC of 0.88, 0.91, and 0.95 for Qmax, Qavg, and voided volume, respectively. Among female participants, we observed a PCC of 0.78, 0.93, and 0.96 for Qmax, Qavg, and voided volume, respectively. The Qmax showed a statistically significant difference in both sexes between the 2 methods, although the absolute value was small. @*Conclusions@#Uroflowmetry using acoustic analysis demonstrates comparable findings to conventional uroflowmetry. This provides an opportunity to perform uroflowmetry in the clinic or at home in a reliable, inexpensive manner. Future large-scale prospective studies are required to further validate our results.

Open Partial Nephrectomy vs. Robotassisted Partial Nephrectomy for a Renal Tumor Larger than 4 cm: a Propensity Score Matching Analysis

Background@#To compare open partial nephrectomy (OPN) and robot-assisted partial nephrectomy (RAPN) in the management of renal tumors larger than 4 cm. @*Methods@#Clinical records of 220 patients who underwent OPN or RAPN for a single renal tumor ≥ 4.0 cm with a normal contralateral kidney were reviewed. After determining the propensity score, surgical parameters, functional outcomes, and oncological outcomes were compared between OPN (n = 67) and RAPN (n = 67) groups of patients. @*Results@#The RAPN group had longer operation time (149.0 min vs. 173.3 min, P = 0.030) and longer ischemic time (20.3 min vs. 29.4 min, P = 0.001), but shorter hospital stay (8.2 days vs 6.0 days, P = 0.001) than the OPN group. Estimated blood loss (P = 0.053), pain visual analog score at 1 day postoperatively (P = 0.194), and complications of grade III or higher (P = 0.403) were similar between OPN and RAPN groups. There was no radical conversion or positive surgical margin in either group. Mean change in 6-month estimated glomerular filtration rate was significantly better in the RAPN group (−8.2 vs. −3.1, P = 0.027). There was no statistical difference in recurrence-free survival (P = 0.970) or cancer-specific survival (P = 0.345) between the two groups. @*Conclusion@#RAPN is a safe and feasible surgical modality comparable to OPN for managing renal tumors larger than 4 cm in terms of surgical, functional, and oncological outcomes.

A Novel Mobile Acoustic Uroflowmetry: Comparison With Contemporary Uroflowmetry / 대한배뇨장애요실금학회지

Purpose@#This study aimed to evaluate the accuracy and reliability of a new smartphone-based acoustic uroflowmetry compared to conventional uroflowmetry. @*Methods@#This was a prospective validation study enrolling 128 subjects from September 2017 to April 2018 comparing a novel acoustic uroflowmetry to conventional uroflowmetry in an outpatient urologic clinic at Seoul National University Bundang Hospital. Visual comparison of flow patterns and uroflow parameters such as maximum flow rate (Qmax), average flow rate (Qavg), and voided volume were compared between the 2 techniques. Reliability and accuracy of the uroflowmetry results were compared using Pearson correlation coefficient (PCC) and Student t-test, respectively. @*Results@#One hundred twelve participants were included in the study. Of these, 77 had baseline urologic comorbidities while 35 were normal participants. Flow patterns between the 2 uroflowmetry techniques demonstrated strong visual correlation. When compared to conventional uroflowmetry, all 3 parameters of voiding in male participants showed a very robust correlation with PCC of 0.88, 0.91, and 0.95 for Qmax, Qavg, and voided volume, respectively. Among female participants, we observed a PCC of 0.78, 0.93, and 0.96 for Qmax, Qavg, and voided volume, respectively. The Qmax showed a statistically significant difference in both sexes between the 2 methods, although the absolute value was small. @*Conclusions@#Uroflowmetry using acoustic analysis demonstrates comparable findings to conventional uroflowmetry. This provides an opportunity to perform uroflowmetry in the clinic or at home in a reliable, inexpensive manner. Future large-scale prospective studies are required to further validate our results.

Perioperative Outcomes of Different Surgical Methods Among Bladder Cancer Patients Undergoing Radical Cystectomy With Neobladder Urinary Diversion

Purpose@#To compare perioperative outcomes according to surgical methods among bladder cancer patients who underwent radical cystectomy (RC) with neobladder urinary diversion. @*Materials and Methods@#Between June 2007 and January 2020, 89 bladder cancer patients who received RC with neobladder urinary diversion were enrolled in this study. Patients were stratified into surgical methods – (1) open RC with neobladder (ONB) reconstruction, (2) robotassisted RC (RARC) with extracorporeal neobladder (ECNB) reconstruction, and (3) RARC with intracorporeal neobladder (ICNB) reconstruction. Perioperative outcomes were compared among the 3 groups, with major complications defined according to Clavien-Dindo grades III–V within 90 days. Logistic regression analysis was performed to identify significant factors for postoperative complications. @*Results@#Of 89 patients, 28 (31%) had ONB, 31 (35%) had ECNB, and 30 (34%) had ICNB. The median operative time was 471 minutes, and the ICNB group (424.5 minutes) was significantly less than ONB (444.5 minutes) and ECNB groups (542.9 minutes) (p=0.001). Transfusion rate was also significantly less in the ICNB group (13%) (p=0.001). Complications were recorded in 67 patients (75%) and major complications in 22 of all patients (25%). The major complication rate was significantly less in ICNB (13.4%) than in ONB (25%) and ECNB (35%) (p=0.003). Multivariate analysis showed surgical methods (ICNB) (odds ratio [OR], 0.709; p=0.003) and age (OR, 1.150; p=0.001) were significant factors related to occurrence of major postoperative complications. @*Conclusions@#RARC with ICNB reduces postoperative complications compared to ONB and ECNB.

Effect of Body Mass Index and Hypertension on the Prognosis of Upper Tract Urothelial Carcinoma After Radical Nephroureterectomy

Purpose@#To investigate the impact of preoperative underlying hypertension (HTN) and body mass index (BMI) on oncologic outcomes in patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNUx). @*Materials and Methods@#From May 2003 to December 2018, 453 UTUC patients who underwent RNUx at a single institution were enrolled in the study. All patients were divided into 2 groups according to preoperative HTN and BMI (cutoff 24 kg/m2) and perioperative parameters and recurrence outcomes were compared. Multivariate Cox proportional hazard analysis was performed to identify the significance of HTN and BMI regarding UTUC recurrence. @*Results@#Among a total 453 UTUC patients, 233 (51.4%) had HTN, and 222 (49.0%) had BMI ≥24 kg/m2. The HTN versus no-HTN group had similar perioperative outcomes, except for the rate of diabetes (p<0.001). The high-BMI versus low-BMI group had similar outcomes, except for the prevalence of HTN (p=0.026). During median follow-up of 23 months, 5-year recurrence-free survival rates were 76.2% in the HTN group and 79.9% in the non-HTN group (p=0.002), and 77.3% in the low-BMI group and 79.0% in the high-BMI group (p=0.007). Multivariate analysis showed that BMI (hazard ratio [HR], 0.740; p=0.046), and HTN (HR, 1.687; p=0.005) were significant predictors of cancer recurrence. @*Conclusions@#Among UTUC patients who underwent RNUx, patients with HTN and low-BMI showed worse prognosis regarding cancer recurrence. To validate our results, the mechanisms of association between HTN, BMI, and UTUC should be investigated in further prospective studies.

Effect of Body Mass Index and Hypertension on the Prognosis of Upper Tract Urothelial Carcinoma After Radical Nephroureterectomy

Purpose@#To investigate the impact of preoperative underlying hypertension (HTN) and body mass index (BMI) on oncologic outcomes in patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNUx). @*Materials and Methods@#From May 2003 to December 2018, 453 UTUC patients who underwent RNUx at a single institution were enrolled in the study. All patients were divided into 2 groups according to preoperative HTN and BMI (cutoff 24 kg/m2) and perioperative parameters and recurrence outcomes were compared. Multivariate Cox proportional hazard analysis was performed to identify the significance of HTN and BMI regarding UTUC recurrence. @*Results@#Among a total 453 UTUC patients, 233 (51.4%) had HTN, and 222 (49.0%) had BMI ≥24 kg/m2. The HTN versus no-HTN group had similar perioperative outcomes, except for the rate of diabetes (p<0.001). The high-BMI versus low-BMI group had similar outcomes, except for the prevalence of HTN (p=0.026). During median follow-up of 23 months, 5-year recurrence-free survival rates were 76.2% in the HTN group and 79.9% in the non-HTN group (p=0.002), and 77.3% in the low-BMI group and 79.0% in the high-BMI group (p=0.007). Multivariate analysis showed that BMI (hazard ratio [HR], 0.740; p=0.046), and HTN (HR, 1.687; p=0.005) were significant predictors of cancer recurrence. @*Conclusions@#Among UTUC patients who underwent RNUx, patients with HTN and low-BMI showed worse prognosis regarding cancer recurrence. To validate our results, the mechanisms of association between HTN, BMI, and UTUC should be investigated in further prospective studies.

Development and validation of a clinical nomogram predicting bladder outlet obstruction via routine clinical parameters in men with refractory nonneurogenic lower urinary tract symptoms / 亚洲男科学杂志(英文版)

We aimed to develop and validate a clinical nomogram predicting bladder outlet obstruction (BOO) solely using routine clinical parameters in men with refractory nonneurogenic lower urinary tract symptoms (LUTS). A total of 750 eligible patients ≥50 years of age who had previously not responded (International Prostate Symptom Score [IPSS] improvement <4 points) to at least three different kinds of LUTS medications (including a-blocker) for the last 6 months were evaluated as subcohorts for nomogram development (n = 570) and for split-sample validation (n = 180). BOO was defined as Abrams-Griffiths number ≥40, or 20-39.9 with a slope of linear passive urethral resistance ratio >2 cmH2O ml-1 s-1. A stepwise multivariable logistic regression analysis was conducted to determine the predictors of BOO, and b-coefficients of the final model were selected to create a clinical nomogram. The final multivariable logistic regression model showed that age, IPSS, maximum urinary flow rate, postvoid residual volume, total prostate volume, and transitional zone index were significant for predicting BOO; these candidates were used to develop the final nomogram. The discrimination performance of the nomogram was 88.3% (95% CI: 82.7%-93.0%, P < 0.001), and the nomogram was reasonably well-fitted to the ideal line of the calibration plot. Independent split-sample validation revealed 80.9% (95% CI: 75.5%-84.4%, P < 0.001) accuracy. The proposed BOO nomogram based solely on routine clinical parameters was accurate and validated properly. This nomogram may be useful in determining further treatment, primarily focused on prostatic surgery for BOO, without impeding the detection of possible BOO in men with LUTS that is refractory to empirical medications.

A Study on the Complications and Pathologic Results of the Patients Undergoing Magnetic Resonance Imaging Guided Prostate Biopsy

PURPOSE: We aimed to study clinicopathological parameters and complications of patients who underwent magnetic resonance imaging-transrectal ultrasonography fusion guided prostate biopsy (MRI-TRUS FGB). MATERIALS AND METHODS: We investigated 576 patients who underwent MRI-TRUS FGB of prostate from May 2003 to December 2017 retrospectively. The clinicopathological features and complications were presented, using the modified Clavien-Dindo classification system. RESULTS: Fourteen patients (2.4%) readmitted within 30 days after MRI-TRUS FGB due to complications, and 85.7% (12 of 14) of them complained mild to moderate complications, the Clavien-Dindo classification grades I and II. The most common complication was hematuria (n=5, 0.9%), followed by acute urinary retention (n=3, 0.5%), dysuria (n=2, 0.3%), fever (n=1, 0.2%), hematochezia (n=1, 0.2%). According to multivariate analysis, only age was the significant risk factor of overall complications and bleeding related complications. Two hundred thirteen patients were diagnosed as prostate cancer after MRI-TRUS FGB. When the Likert suspicious scale of prostate cancer on apparent diffusion coefficient (ADC) was ≤4, 27.8% (137 of 493) were diagnosed as prostate cancer, of whom 56.2% (77 of 137) were confirmed as prostate cancer only at randomized 12 cores. When the ADC suspicious level was grade 5, 91.6% (76 of 83) were diagnosed as prostate cancer, of whom 11.8% (7 of 76) were confirmed as prostate cancer only at randomized 12 cores. CONCLUSIONS: The present study demonstrates the safety of MRI-TRUS FGB in terms of complications. When ADC suspicious level is grade 5, MRI-TRUS FGB alone could be a reasonable measure to diagnose prostate cancer, but randomized 12-core prostate biopsy would be recommended additionally when ADC suspicious level is ≤4.

Does prostate-specific antigen (PSA) mass or free PSA mass improve the accuracy of predicting total prostate volume in relation to obesity in men with biopsy-proven benign prostatic hyperplasia? / 亚洲男科学杂志(英文版)

We evaluated whether the prostate-specific antigen (PSA) mass or free PSA (fPSA) mass (i.e., absolute amount of total circulating PSA or fPSA protein, respectively), versus serum PSA or fPSA concentration, improves the accuracy of predicting the total prostate volume (TPV) in relation to obesity. Among men whose multicore (≥12) transrectal prostate biopsy was negative, 586 who had a PSA of ≤10 ng ml-1 and underwent the fPSA test prior to biopsy were enrolled. The PSA mass or fPSA mass (μ g) was calculated by multiplying the serum level by plasma volume. At each TPV cut-off point (30 ml, 40 ml, and 50 ml), the areas under the receiver operating characteristics curve (AUCs) of each variable were compared in obesity-based subgroups. AUCs of fPSA and fPSA mass for predicting TPV were significantly larger than those for PSA and PSA mass by 8.7%-12.1% at all cut-off points. Subgroup analyses based on obesity showed that, although PSA mass and fPSA mass enhanced accuracy by 4% (P = 0.031) and 1.8% (P = 0.003), respectively, for determining TPVs of ≥30 ml and ≥50 ml in obese and overweight men, they did not improve the accuracy in most other combinations of the degrees of obesity with TPV cut-off points. Thus, compared with serum PSA or fPSA, the absolute amount of PSA or fPSA protein mass improved the accuracy of predicting TPV in obese men very minimally and only for certain TPV cut-off points. Hence, these indicators may not provide clinically meaningful improvement in predicting TPV in obese men.

Focal lesion at the midline of the prostate on transrectal ultrasonography: take it or leave it?

PURPOSE: The purpose of this study was to analyze the detection rate of prostate cancers from targeted biopsy specimens of midline focal lesions and to investigate the ultrasonographic findings to reduce unnecessary additional targeted biopsies. METHODS: Ninety-eight men with midline focal lesions detected on transrectal ultrasonography were enrolled. Additional targeted biopsies for midline focal lesions were performed after 12-core random systematic biopsies. Correlations between the ultrasonographic characteristics of midline focal lesions and the pathologic results were analyzed. RESULTS: Twenty of 98 targeted biopsy cores (20.4%) were positive for malignancy. In a univariate analysis, midline focal lesions without bulging contours (P=0.023), with involved margins (P=0.001), without hypoechoic perilesional rims (P=0.005), and with longer diameters (P=0.005) were statistically significant for cancer detection. In a multivariate analysis, involved margin (P=0.027), having longer diameter (P=0.011) or absence of hypoechoic perilesional rim (P=0.025) made a statistically significant contribution to cancer detection. CONCLUSION: Biopsy of midline focal lesions was not always non-significant in the detection of prostate cancer. Additional targeted biopsies should be considered in cases of midline focal lesions with involved margins but without hypoechoic perilesional rims.

Elevated Ki-67 (MIB-1) Expression as an Independent Predictor for Poor Prognosis After Radical Cystectomy for Bladder Cancer

PURPOSE: We tried to investigate the clinical impact of Ki-67 (MIB-1) expression on the oncological and survival outcomes in patients with bladder cancer (BCa) after the radical cystectomy. MATERIALS AND METHODS: We retrospectively analyzed the data of 230 patients who were treated by radical cystectomy for BCa. Multivariate Cox-proportional hazards models and logistic regression tests were performed to evaluate the prognostic value of each variable. RESULTS: The patients with positive Ki-67 expression showed significant worse clinical characteristics and pathologic outcomes than negative Ki-67 group. Furthermore, the patients with Ki-67 expression showed significant worse recurrence (p=0.018) and cancer-specific mortality free survival (p=0.019) than negative Ki-67 group. The overall survival was also revealed to be inferior in Ki-67 positive group than Ki-67 negative group but the statistical significance was marginal (p=0.062). Subsequent multivariate Cox analyses showed that Ki-67 was independent predictor for disease recurrence after surgery (hazard ratio, 3.142; 95% CI, 1.287–7.671; p=0.012). CONCLUSIONS: In our study, high Ki-67 expression was significantly related with worse clinical outcomes after radical cystectomy in the patients with BCa. Further prospective and basic researches are needed to validate the true prognostic value of Ki-67.

Pelvic Lymph Node Metastases in Prostate Cancer: Preoperative Detection With Dynamic Contrast-Enhanced Magnetic Resonance Imaging Compared With Postoperative Pathologic Result of Pelvic Lymph Node Dissection

PURPOSE: The aim of this study is evaluating the accuracy of preoperative magnetic resonance imaging (MRI) in patients who underwent pelvic lymph node dissection (PLND). MATERIALS AND METHODS: The medical records of 1,528 patients who underwent radical prostatectomy and PLND from 2003 to 2017 in Seoul National University Bundang Hospital were retrospectively reviewed. We evaluated the various clinicopathologic variables including preoperative MRI findings and pathologic lymph node (LN) metastasis. The prediction model for pathologic LN metastasis was assessed using univariate and multivariable logistic regression analyses and areas under receiver operating characteristic (ROC) curves. RESULTS: The mean age of our cohort was 66.4±6.7 years. Positive LN finding of preoperative MRI finding was observed in 9.4% (145 of 1,528) of patients. 5.3% (81 of 1,528) of patients had confirmed final pathologic LN metastases. Sensitivity and specificity of preoperative MRI were 30.8% and 91.7%, respectively. Multivariable analysis showed that preoperative MRI findings, clinical stage and biopsy Gleason score were independent significant predictors for pathologic LN metastasis (p < 0.001, p=0.002, and p < 0.001, respectively). Prediction model using preoperative MRI findings and National Comprehensive Control Network risk stratification showed fair accuracy using ROC analysis. CONCLUSIONS: Preoperative MRI findings for pathologic LN metastasis showed limited prediction value. A large-scale, multicenter, prospective study is needed to fully evaluate the clinical significance of preoperative MRI.

Factor Analysis of Intraoperative Radical Conversion During Partial Nephrectomy: Single Surgeon Experience

PURPOSE: Preoperative aspects and dimensions used for an anatomical (PADUA) classification is useful to predict perioperative complications and warm ischemia time. However, it remains uncertain whether PADUA classification can predict intraoperative conversion from partial nephrectomy (PN) to radical nephrectomy (RN). We evaluate whether PADUA classification parameters can predict conversion to RN during PN. MATERIALS AND METHODS: We retrospectively assessed data of 593 patients who underwent open PN and robotic PN for renal tumors by a single surgeon at a single tertiary center between December 2003 and September 2017. Intraoperative conversion to RN was performed in 17 of 593 patients who initially underwent PN. We evaluated the factors influencing the surgical modalities including PN and radical conversion cases. Then, the factors significantly associated with conversion to RN were further analyzed. RESULTS: There were no significant differences between the 2 groups in age, longitudinal location, exophytic rate, and rim or face locations of renal masses. Renal sinus involvement, urinary collecting system involvement, and renal mass size were variables that predicted radical conversion, using univariate analysis. Renal sinus involvement (odds ratio [OR], 9.075; p=0.049) and urinary collecting system involvement (OR, 3.944; p=0.029) were independent predictors of intraoperative radical conversion, using multivariate analysis. CONCLUSIONS: The PADUA classification is a useful tool to predict intraoperative conversion from PN to RN. Renal sinus involvement and urinary collecting system involvement are the best predictors of intraoperative conversion from PN to RN.

Risk Determination for Localised Renal Cell Carcinomas under 4 cm or Less: A Multi-institutional Analysis

PURPOSE: To determine the malignant potential in clinically localised small renal cell carcinoma (RCC) (≤4cm) in patients using postoperative pathologic outcomes. MATERIALS AND METHODS: We performed a retrospective analysis of 2,085 patients in 7 urology centres with clinical T1a RCC who underwent nephrectomy. The pathologic upstaging group (PUG) was defined by pathologic T3a after the operation. Multivariate analyses were used to examine predicting factors for the risk of PUG. Next, Kaplan-Meier analysis was used to examine the PUG for worse recurrence-free survival during the follow-up period. RESULTS: The PUG had 73 patients (3.5%); they were older and had a larger tumour size than the other patients (all p<0.001). After adjusting for clinical characteristics, age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02–1.06) and tumour size greater than 3 cm (OR, 1.94; 95% CI, 1.21–3.11) were found to be independent predictors for the PUG after nephrectomy. Furthermore, the PUG had worse recurrence-free survival during the follow-up period. CONCLUSIONS: In this multi-institution analysis, RCC 3 cm or greater in older patients had a high malignant potential compared to relatively small tumours in younger patients. These results may be helpful for stratifying patients to manage small renal masses.

Clinical Significance of Positive Surgical Margin after Radical Prostatectomy according to Pathological Stage

PURPOSE: The purpose of this study was to investigate the positive surgical margin (PSM) as a predictive factor of biochemical recurrence (BCR) in prostate cancer (PCa) patients after radical prostatectomy (RP) according to each pathological stage. MATERIALS AND METHODS: The records of 3,037 patients receiving RP were retrospectively reviewed. All patients were divided into 6 groups depending on pathological stage and presence of PSM. Cox proportional hazard analyses were performed to show the significance of PSM in all patients and in subgroup patients (T2, T3a, and T3b). The Kaplan-Meier analysis showed BCR-free survival rate of each group. RESULTS: Among total 3.307 patients, the mean age was 65.89 years and PSM rate was 18.7%. During the 47.1 months, 550 patients had experienced BCR (26.2%). According to groups, prostate-specific antigen, Gleason score, and BCR were significantly different. Ten-year BCR-free survival rate was 87.1% (T2R0), 65.9% (T2R1), 60.1% (T3aR0), 43.0% (T3aR1), 20.8% (T3bR0), and 5.8% (T3bR1). Each group had statistical differences with BCR-free survival except T2R1 and T3aR0 (p=0.090). PSM was significant in multivariate Cox analyses in total patients (hazard ratio, 2.091; 95% confidence interval, 1.724–2.536; p<0.001) and in all subgroup with each stages. CONCLUSIONS: PSM is a significant predictor to BCR after RP in all PCa patients and in each stage. T2R1 PCa had a similar BCR-free survival rate to T3R0 patients during long-term follow-up, therefore careful management to T2R1 PCa as T3 should be necessary.

Comparison of Perioperative Outcomes in Patients Undergoing Robotic and Laparoscopic Adrenalectomy

PURPOSE: To compare outcomes of robotic adrenalectomy with conventional laparoscopic adrenalectomy. MATERIALS AND METHODS: This retrospective study included 63 patients who underwent robotic or laparoscopic adrenalectomy between March 2005 and April 2016, with all operations performed using a transperitoneal approach. Outcomes were compared in the 29 patients who underwent robotic adrenalectomy and the 34 who underwent conventional laparoscopic adrenalectomy. RESULTS: Mean age (53.1±12.2 years vs. 51.4±15.1 years, p=0.631) and body mass index (25.9±3.8 kg/m2 vs. 25.2±3.5 kg/m2, p=0.461) were similar in the robotic and laparoscopic groups. A significant percentage of patients in the robotic group had undergone prior abdominal surgery (38% vs. 12%, p=0.015). Mean tumor sizes (3.0±1.5 cm vs. 3.7±2.7 cm, p=0.134) and the percentage of incidentalomas (75.9% vs. 73.5%, p=0.354) were similar in the robotic and laparoscopic groups. There were no statistical significance between-group differences in tumor size, operative time, estimated blood loss, perioperative hemoglobin change, length of hospital stay, and complication rates. Pathologic diagnosis showed that pheochromocytoma (21% vs. 3%) and metastatic tumor (24% vs. 6%) were more frequent in the robotic than in the laparoscopic group (p=0.019). Subgroup analysis of patients with low tumor volume (≤6.8 cm3) showed that operation time was significantly shorter in the robotic than in the laparoscopic group (p=0.045). CONCLUSIONS: Robotic adrenalectomy is feasible, with outcomes comparable to those of laparoscopic adrenalectomy.

A clinicogenetic model to predict lymph node invasion by use of genome-based biomarkers from exome arrays in prostate cancer patients

PURPOSE: Genetic variations among prostate cancer (PCa) patients who underwent radical prostatectomy (RP) and pelvic lymph node dissection were evaluated to predict lymph node invasion (LNI). Exome arrays were used to develop a clinicogenetic model that combined clinical data related to PCa and individual genetic variations. MATERIALS AND METHODS: We genotyped 242,186 single-nucleotide polymorphisms (SNPs) by using a custom HumanExome BeadChip v1.0 (Illumina Inc.) from the blood DNA of 341 patients with PCa. The genetic data were analyzed to calculate an odds ratio as an estimate of the relative risk of LNI. We compared the accuracies of the multivariate logistic model incorporating clinical factors between the included and excluded selected SNPs. The Cox proportional hazard models with or without genetic factors for predicting biochemical recurrence (BCR) were analyzed. RESULTS: The genetic analysis indicated that five SNPs (rs75444444, rs8055236, rs2301277, rs9300039, and rs6908581) were significant for predicting LNI in patients with PCa. When a multivariate model incorporating clinical factors was devised to predict LNI, the predictive accuracy of the multivariate model was 80.7%. By adding genetic factors in the aforementioned multivariate model, the predictive accuracy increased to 93.2% (p=0.006). These genetic variations were significant factors for predicting BCR after adjustment for other variables and after adding the predictive gain to BCR. CONCLUSIONS: Based on the results of the exome array, the selected SNPs were predictors for LNI. The addition of individualized genetic information effectively enhanced the predictive accuracy of LNI and BCR among patients with PCa who underwent RP.

Clinical effect of abiraterone acetate in Korean patients with metastatic castration-resistant prostate cancer according to duration of androgen deprivation therapy

PURPOSE: Few data are available concerning the clinical outcome of abiraterone acetate treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) in terms of the duration of androgen deprivation therapy (ADT) before diagnosis of CRPC. We investigated the clinical efficacy of abiraterone acetate according to the duration of ADT. MATERIALS AND METHODS: We reviewed the medical records of 20 patients with mCRPC who received abiraterone acetate after failure of docetaxel chemotherapy from May 2012 to March 2014 at Seoul National University Bundang Hospital. Clinical factors including prostate-specific antigen (PSA) nadir level, time to PSA nadir, PSA doubling time, PSA response, and modes of progression (PSA, radiologic, clinical) were analyzed. Disease progression was classified according to the Prostate Cancer Working Group 2 criteria. RESULTS: The mean age and PSA value of the entire cohort were 76.0+/-7.2 years and 158.8+/-237.9 ng/mL, respectively. The median follow-up duration was 13.4+/-6.7 months. There were no statistically significant differences in clinical characteristics between patients who received abiraterone acetate with ADT duration or =35 months. There were also no significant differences in terms of PSA progression-free survival, radiologic progression-free survival, and clinical progression-free survival between patients with ADT duration or =35 months. CONCLUSIONS: Although this was a retrospective study with a small sample size, we did not observe any statistically significant differences in the clinical response to abiraterone acetate between mCRPC patients with long ADT duration and those with short ADT duration in terms of disease progression-free survival.