Prediction of Pathologic Findings with MRI-Based Clinical Staging Using the Bayesian Network Modeling in Prostate Cancer: A Radiation Oncologist Perspective / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study aimed to develop a model for predicting pathologic extracapsular extension (ECE) and seminal vesicle invasion (SVI) while integrating magnetic resonance imaging-based T-staging (cTMRI, cT1c-cT3b). @*Materials and Methods@#A total of 1,915 who underwent radical prostatectomy between 2006-2016 met the inclusion/exclusion criteria. We performed a multivariate logistic regression analysis as well as Bayesian network (BN) modeling based on possible confounding factors. The BN model was internally validated using 5-fold validation. @*Results@#According to the multivariate logistic regression analysis, initial prostate-specific antigen (iPSA) (β=0.050, p < 0.001), percentage of positive biopsy cores (PPC) (β=0.033, p < 0.001), both lobe involvement on biopsy (β=0.359, p=0.009), Gleason score (β=0.358, p < 0.001), and cTMRI (β=0.259, p < 0.001) were significant factors for ECE. For SVI, iPSA (β=0.037, p < 0.001), PPC (β=0.024, p < 0.001), Gleason score (β=0.753, p < 0.001), and cTMRI (β=0.507, p < 0.001) showed statistical significance. BN models to predict ECE and SVI were also successfully established. The overall area under the receiver operating characteristic curve (AUC)/accuracy of the BN models were 0.76/73.0% and 0.88/89.6% for ECE and SVI, respectively. According to internal comparison between the BN model and Roach formula, BN model had improved AUC values for predicting ECE (0.76 vs. 0.74, p=0.060) and SVI (0.88 vs. 0.84, p < 0.001). @*Conclusion@#Two models to predict pathologic ECE and SVI integrating cTMRI were established and installed on a separate website for public access to guide radiation oncologists.

De Ritis Ratio (Aspartate Transaminase/Alanine Transaminase) as a Significant Prognostic Factor With Upper Urinary Tract Carcinoma Who Underwent Radical Nephroureterectomy and Adjuvant Chemotherapy

Purpose@#To investigate the correlation between preoperative De Ritis ratio (aspartate transaminase [AST]/alanine transaminase [ALT]) and postoperative clinical outcome in patients with upper urinary tract carcinoma (UTUC) who underwent radical nephroureterectomy (RNU) and adjuvant chemotherapy (ACH). @*Materials and Methods@#We respectively analyzed the clinical and pathological data of 102 patients who underwent RNU and ACH for UTUC. Patients were divided into 2 groups, according to the optimal value of AST/ALT ratio. The effect of the AST/ALT ratio was analyzed by the Kaplan-Meier method and Cox regression hazard models for patients’ cancer-specific survival (CSS) and overall survival (OS). @*Results@#Mean survival time was 50.5±41.2 months. Mean age was 61.4±9.7years. Forty-one of the patients (46.5%) were in the high AST/ALT group. According to receiver operating characteristic analysis, the optimal AST/ALT ratio was 1.2. In Kaplan-Meier analyses, the high AST/ALT group showed worse outcomes in OS (p=0.007) and CSS (p=0.011). Using Cox regression models of clinical and pathological parameters to predict OS, high AST/ALT ratio (hazard ratio [HR], 5.428; 95% confidence interval [CI]; 1.803–16.334; p=0.002), pathological T3 (pT3) or higher (HR, 1.464; 95% CI; 1.156-1.857; p=0.002), and to predict CSS, high AST/ALT ratio (HR, 4.417; 95% CI; 1.545–12.632; p=0.005), and pT3 or higher (HR, 1.475; 95% CI; 1.172–1.904; p=0.002) were determined as independent prognostic factors. @*Conclusions@#Pretreatment AST/ALT ratio is a significant independent predictor of CSS and OS in advanced UTUC patients receiving systemic ACH after RNU.

Glue Embolization of Lymphopseudoaneurysm for Chylous Ascites after Retroperitoneal Surgery

Objective@#To assess the safety and efficacy of lymphopseudoaneurysm (LPA) glue (n-butyl cyanoacrylate [NBCA]) embolization in the management of chylous ascites after retroperitoneal surgery. @*Materials and Methods@#A retrospective analysis from January 2014 to October 2018 was performed in six patients (4 females and 2 males; mean age, 45.3 ± 14.2 years; range, 26–61 years) who underwent LPA embolization for chylous ascites developing after retroperitoneal surgery involving the perirenal space (four donor nephrectomies, one partial nephrectomy, and one retroperitoneal lymphadenectomy). After placing a percutaneous drainage catheter into the LPA or adjacent lymphocele, embolization was performed by filling the LPA itself with a mixture of glue and Lipiodol (Guerbet). @*Results@#Daily drainage from percutaneously placed drains exceeded 300 mL/day despite medical and surgical treatment (volume: mean, 1173 ± 1098 mL; range, 305–2800 mL). Intranodal lymphangiography was performed in four of the six patients and revealed leakage in 2 patients. Percutaneous embolization of the LPA was successful in all patients using an NBCA and Lipiodol mixture in a ratio of 1:1–1:2 (volume: mean, 4.3 ± 1.1 mL; range, 3–6 mL). Chylous ascites was resolved and the drainage catheter was removed in all patients within 4 days after the procedure (mean, 2.0 ± 1.8 days; range, 0–4 days). No procedure-related complications or recurrence of chylous ascites occurred during a mean follow-up period of 37.3 months (range, 21.1–48.4 months). @*Conclusion@#Glue embolization of LPA has the potential to be a feasible and effective treatment method for the management of chylous ascites after retroperitoneal surgery.

Clinical Usefulness and Predictability of Seoul National University Prostate Cancer Risk Calculator (SNU-PCRC)

Purpose@#To evaluate the clinical usefulness of the Seoul National University Prostate Cancer Risk Calculator (SNU-PCRC) to reduce unnecessary prostate biopsy and to increase the detection rate of high-risk cancer. @*Materials and Methods@#We retrospectively analyzed 546 patients who underwent prostate biopsy between 2014 and 2016. The subjects were divided into 2 groups based on the type of risk calculator used: conventional and SNU-PCRC group. In the SNU-PCRC group, prostate biopsy was recommended when the probability of SNU-PCRC was more than 30%. @*Results@#The SNU-PCRC group had significantly smaller prostate volume (p=0.010) and significantly more digital rectal examination and transrectal ultrasonography (TRUS) abnormalities (p=0.011 and p=0.010, respectively). Overall detection (71.9% vs. 32.1%) and high-risk cancer detection rates (40.6% vs. 19.3%) were significantly higher in the gray zone (prostate-specific antigen=4-10 ng/mL) (p<0.001 and p=0.006). The group with prostate cancer risk ≥30% on the SNU-PCRC compared to <30% group, overall detection rate of 72.3% versus 30.2% and high-risk detection rate of 60.6% versus 18.3% were significantly different (p<0.001 and p<0.001). Applying the SNU-PCRC to the conventional group could avoid unnecessary prostate biopsy in 50.6%. @*Conclusions@#SNU-PCRC is clinically useful to reduce unnecessary prostate biopsy and increase overall detection rate and high-risk cancer detection rate.

Clinical Usefulness and Predictability of Seoul National University Prostate Cancer Risk Calculator (SNU-PCRC)

Purpose@#To evaluate the clinical usefulness of the Seoul National University Prostate Cancer Risk Calculator (SNU-PCRC) to reduce unnecessary prostate biopsy and to increase the detection rate of high-risk cancer. @*Materials and Methods@#We retrospectively analyzed 546 patients who underwent prostate biopsy between 2014 and 2016. The subjects were divided into 2 groups based on the type of risk calculator used: conventional and SNU-PCRC group. In the SNU-PCRC group, prostate biopsy was recommended when the probability of SNU-PCRC was more than 30%. @*Results@#The SNU-PCRC group had significantly smaller prostate volume (p=0.010) and significantly more digital rectal examination and transrectal ultrasonography (TRUS) abnormalities (p=0.011 and p=0.010, respectively). Overall detection (71.9% vs. 32.1%) and high-risk cancer detection rates (40.6% vs. 19.3%) were significantly higher in the gray zone (prostate-specific antigen=4-10 ng/mL) (p<0.001 and p=0.006). The group with prostate cancer risk ≥30% on the SNU-PCRC compared to <30% group, overall detection rate of 72.3% versus 30.2% and high-risk detection rate of 60.6% versus 18.3% were significantly different (p<0.001 and p<0.001). Applying the SNU-PCRC to the conventional group could avoid unnecessary prostate biopsy in 50.6%. @*Conclusions@#SNU-PCRC is clinically useful to reduce unnecessary prostate biopsy and increase overall detection rate and high-risk cancer detection rate.

Application of the International Metastatic Renal Cell Carcinoma Database Consortium and Memorial Sloan Kettering Cancer Center Risk Models in Patients with Metastatic Non-Clear Cell Renal Cell Carcinoma: A Multi-Institutional Retrospective Study Using the Korean Metastatic Renal Cell Carcinoma Registry / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) and the Memorial Sloan Kettering Cancer Center (MSKCC) risk models were developed predominantly with clear cell renal cell carcinoma (RCC). Accordingly, whether these two models could be applied to metastatic non-clear cell RCC (mNCCRCC) as well has not been well-known and was investigated herein. MATERIALS AND METHODS: From the Korean metastatic RCC registry, a total of 156 patients (8.1%) with mNCCRCC among the entire cohort of 1,922 patients were analyzed. Both models were applied to predict first-line progression-free survival (PFS), total PFS, and cancer-specific survival (CSS). RESULTS: The median first-line PFS, total PFS, and CSS were 5, 6, and 24 months, respectively. The IMDC risk model reliably discriminated three risk groups to predict survival: the median first-line PFS, total PFS, and CSS for the favorable, intermediate, and poor risk groups were 9, 5, and, 2 months (p=0.001); 14, 7, and 2 months (p < 0.001); and 41, 21, and 8 months (p < 0.001), all respectively. The MSKCC risk model also reliably differentiated three risk groups: 9, 5, and, 2 months (p=0.005); 10, 7, and 3 months (p=0.002); and 50, 21, and 8 months (p < 0.001), also all respectively. The concordance indices were 0.632 with the IMDC model and 0.643 with the MSKCC model for first-line PFS: 0.748 and 0.655 for CSS. CONCLUSION: The current IMDC and MSKCC risk models reliably predict first-line PFS, total PFS, and CSS in mNCCRCC.

Comprehensive Molecular Characterization of Urological Malignancies: Literature Review of Landmark Studies

Owing to recent advancements in next-generation sequencing and bioinformatics, genetic data of urological malignancies exponentially studied and published. Application of precision medicine strategies for cancer diagnosis, management is just around the corner, and we need to prepare for this paradigm change. For this reason, we performed the literature reviews of 13 landmark studies for urological malignancies, 5 for prostate cancer, 5 for renal cell carcinoma, and 3 for urothelial carcinoma. Furthermore, we reviewed potentially druggable genes for urological malignancies that have in vivo/in vitro evidence. Finally, we selected total 255 genes included important mutations, structural variations, copy number alterations, clinically informative genes and potential drug target genes for prostate cancer, renal cell carcinoma, and urothelial carcinoma. This literature review and comprehensive molecular characterization of urological malignancies make help to understanding genetic backgrounds of the disease. However, there was less than 5% of Asian data included in current landmark studies for urological malignancies; thus we need to build up the large-scaled genetic studies for Korean population.

Selection Criteria for Active Surveillance of Patients with Prostate Cancer in Korea: A Multicenter Analysis of Pathology after Radical Prostatectomy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Korean patients with prostate cancer (PC) typically present with a more aggressive disease than patients in Western populations. Consequently, it is unclear if the current criteria for active surveillance (AS) can safely be applied to Korean patients. Therefore, this study was conducted to define appropriate selection criteria for AS for patients with PC in Korea. MATERIALS AND METHODS: We conducted a multicenter retrospective study of 2,126 patients with low risk PC who actually underwent radical prostatectomy. The primary outcome was an unfavorable disease, which was defined by non-organ confined disease or an upgrading of the Gleason score to ≥ 7 (4+3). Predictive variables of an unfavorable outcome were identified by multivariate analysis using randomly selected training samples (n=1,623, 76.3%). We compared our selected criteria to various Western criteria for the primary outcome and validated our criteria using the remaining validation sample (n=503, 23.7%). RESULTS: A non-organ confined disease rate of 14.9% was identified, with an increase in Gleason score ≥ 7 (4+3) of 8.7% and a final unfavorable disease status of 20.8%. The following criteria were selected: Gleason score ≤ 6, clinical stage T1-T2a, prostate-specific antigen (PSA) ≤ 10 ng/mL, PSA density < 0.15 ng/mL/mL, number of positive cores ≤ 2, and maximum cancer involvement in any one core ≤ 20%. These criteria provided the lowest unfavorable disease rate (11.7%) when compared to Western criteria (13.3%-20.7%), and their validity was confirmed using the validation sample (5.9%). CONCLUSION: We developed AS criteria which are appropriate for Korean patients with PC. Prospective studies using these criteria are now warranted.

Eleven-year Cumulative Incidence and Estimated Lifetime Prevalence of Urolithiasis in Korea: a National Health Insurance Service-National Sample Cohort Based Study

BACKGROUND: The purpose of this study was estimation of the cumulative incidence and lifetime prevalence of urolithiasis in Korea. METHODS: We used a National Health Insurance Service (NHIS) sample cohort dataset that included approximately 1 million individuals from Korea. Data from January 2002 to December 2013 were collected. We calculated the annual prevalence, recurrence rate, and estimate lifetime prevalence of urolithiasis. Multivariate logistic regression analysis was used to identify risk factors associated with urolithiasis. RESULTS: There were 57,921 diagnosed urolithiasis cases in the NHIS database over the 11 years studied. The annual incidence of urolithiasis increased every year (Poisson regression; hazard ratio, 1.025; P 60 years), income level, diabetes, body mass index, hypertension, and cancer history were identified as contributing factors to urolithiasis. CONCLUSION: This study demonstrates that the annual incidence of urolithiasis in Korea is increasing. The overall standardized lifetime prevalence rate was higher than that reported in a previous report. This study is significant in that it is the first retrospective cohort study to estimate the lifetime prevalence of urolithiasis using a large national retrospective cohort.

Value of the New 5-Tiered Prostate Cancer Grade Group System on Predicting Oncological Outcomes for Radical Prostatectomy Population in Korea

PURPOSE: We evaluated the prognostic value of the 5-tiered grade group in Korean patients who underwent radical prostatectomy. MATERIALS AND METHODS: Between 1996 and 2016, a number of 2,883 consecutive patients who underwent radical prostatectomy were included for the analysis. The impacts of biopsy and pathologic grade group on predicting biochemical recurrence (BCR) were assessed using multivariate analysis. Median follow-up duration was 49.0 months. RESULTS: Mean age was 66.5 years and prostate-specific antigen (PSA) was 11.8 ng/mL. Prostate cancer was locally advanced on magnetic resonance imaging in 13.4%. Biopsy grade group was as follows: 1 (46.8%), 2 (19.8%), 3 (14.2%), 4 (14.1%), and 5 (5.1%). Pathology stage was ≤T2 in 63.6%, T3a in 26.0%, and T3b/T4 in 10.4% patients. Pathologic grade was as follows: 1 (31.3%), 2 (37.9%), 3 (20.2%), 4 (4.7%), and 5 (5.1%). In multivariate analysis using biopsy-related variables, biopsy grade group (1, reference; 2, hazard ratio [HR], 1.771; p=0.001; 3, HR, 2.736; p < 0.001; 4, HR, 2.966; p < 0.001; 5, HR, 3.707; p < 0.001) was associated with BCR-free survival, PSA level and % positive core. In multivariate analysis using pathologic outcomes, pathologic grade group (1, reference; 2, HR, 1.882; p < 0.001; 3, HR, 3.352; p < 0.001; 4, HR, 3.890; p < 0.001; 5, HR: 3.118, p < 0.001) was associated with BCR-free survival in addition to pathologic stage and positive surgical margin. CONCLUSIONS: New 5-tiered grading system could be useful for predicting oncological outcomes in Korean patients although its role for distinguishing outcomes between patients with grade groups 3–5 need to be validated before wide application of this grade system in Korea.

Maternal and fetal outcomes of pregnancies in kidney donors: A 30-year comparative analysis of matched non-donors in a single center

BACKGROUND: Woman kidney donors face obstetric complication risks after kidney donation, such as gestational hypertension and preeclampsia. Studies on childbirth-related complications among Asian women donors are scarce. METHODS: This retrospective cohort study included woman donors aged 45 years or younger at the time of kidney donation in a single tertiary hospital between 1985 and 2014. Pregnancy associated complications were investigated using medical records and telephone questionnaires for 426 pregnancies among 225 donors. Matched non-donor controls were selected by propensity score and the maternal and fetal outcomes were compared with those of donors. Primary outcomes were differences in maternal complications, and secondary outcomes were fetal outcomes in pregnancies of the donor and control groups. RESULTS: A total of 56 cases had post-donation pregnancies. The post-donation pregnancies group was younger at the time of donation and older at the time of delivery than the pre-donation pregnancies group, and there were no differences in primary outcomes between the groups except the proportion receiving cesarean section. Comparison of the complication risk between post-donation pregnancies and non-donor matched controls showed no significant differences in gestational hypertension, preeclampsia, or composite outcomes after propensity score matching including age at delivery, era at pregnancy, systolic blood pressure, body weight, and estimated glomerular filtration ratio (odds ratio, 0.63; 95% confidence interval, 0.19–2.14; P = 0.724). CONCLUSION: This study revealed that maternal and fetal outcomes between woman kidney donors and non-donor matched controls were comparable. Studies with general population pregnancy controls are warranted to compare pregnancy outcomes for donors.

Efficacy of First-Line Targeted Therapy in Real-World Korean Patients with Metastatic Renal Cell Carcinoma: Focus on Sunitinib and Pazopanib

BACKGROUND: To evaluate survival outcomes and prognostic factors for overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) who received sunitinib (SU) and pazopanib (PZ) as first-line therapy in real-world Korean clinical practice. METHODS: Data of 554 patients with mRCC who received SU or PZ at eight institutions between 2012 and 2016 were retrospectively reviewed. Based on the targeted therapy, the patients were divided into SU (n = 293) or PZ (n = 261) groups, and the clinicopathological variables and survival rates of the two groups were compared. A multivariable Cox proportional hazard model was used to determine the prognostic factors for OS. RESULTS: The median follow-up was 16.4 months (interquartile range, 8.3–31.3). Patients in the PZ group were older, and no significant difference was observed in the performance status (PS) between the two groups. In the SU group, the dose reduction rate was higher and the incidence of grade 3 toxicity was more frequent. The objective response rates were comparable between the two groups (SU, 32.1% vs. PZ, 36.4%). OS did not differ significantly between the two groups (SU, 36.5 months vs. PZ, 40.2 months; log-rank, P = 0.955). Body mass index, Eastern Cooperative Oncology Group PS > 2, synchronous metastasis, poor Heng risk criteria, and liver and bone metastases were associated with a shorter OS. CONCLUSION: Our real-world data of Korean patients with mRCC suggested that SU and PZ had similar efficacies as first-line therapy for mRCC. However, PZ was better tolerated than SU in Korean patients.

Partial versus Radical Nephrectomy for T1-T2 Renal Cell Carcinoma in Patients with Chronic Kidney Disease Stage III: a Multiinstitutional Analysis of Kidney Function and Survival Rate

BACKGROUND: To examine survival rates and renal function after partial nephrectomy (PN) and radical nephrectomy (RN) in patients with chronic kidney disease (CKD). METHODS: We studied 4,332 patients who underwent PN or RN for pathological T1a-T2N0M0 renal cell carcinoma from 1988 to 2014. Patients were divided into two subgroups of CKD stage I–II and stage III. Kidney function, and survival outcomes were compared between groups. RESULTS: We included 1,756 patients with CKD I–II and 276 patients with CKD III in the final pair-matched analysis. Kidney function was significantly better preserved in the PN than in the RN group among all patients. However, the beneficial effect of PN on kidney function gradually disappeared over time in CKD III patients. The 5-year overall survival (OS) rates after PN and RN differed in patients with CKD I–II disease (99.4% vs. 96.5%, respectively, P = 0.015). The 5-year OS rates after surgery were not affected by mode of nephrectomy in CKD III patients (97.8% vs. 93.5%, P = 0.103). The 5-year cancer-specific survival rates did not differ between treatment groups in all CKD stage. Cox hazard analysis showed that the operative method was a significant factor for OS in CKD I–II patients (hazard ratio [HR], 0.320; confidence interval [CI], 0.122–0.840; P = 0.021). However, PN was not beneficial in terms of OS in CKD III patients (HR, 0.395; CI, 0.086–1.172; P = 0.117). CONCLUSION: PN is associated with a higher OS rate and better kidney function in patients with preoperative CKD stage I and II, but not in those with CKD stage III.

Effects of Aspirin, Nonsteroidal Anti-inflammatory Drugs, Statin, and COX2 Inhibitor on the Developments of Urological Malignancies: A Population-Based Study with 10-Year Follow-up Data in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to determine the impact of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), statin, and cyclooxygenase 2 (COX-2) inhibitor on the development of kidney, prostate, and urothelial cancers by analyzing the Korean National Health Insurance Service–National Sample Cohort (NHIS-NSC) database. MATERIALS AND METHODS: Among a representative sample cohort of 1,025,340 participants in NHIS-NSC database in 2002, we extracted data of 799,850 individuals who visited the hospital more than once, and finally included 321,122 individuals aged 40 and older. Following a 1-year washout period between 2002 and 2003, we analyzed 143,870 (male), 320,861 and 320,613 individuals for evaluating the risk of prostate cancer, kidney cancer and urothelial cancer developments, respectively, during 10-year follow-up periods between 2004 and 2013. The medication group consisted of patients prescribed these drugs more than 60% of the time in 2003. To adjustfor various parameters of the patients, a multivariate Cox regression model was adopted. RESULTS: During 10-year follow-up periods between 2004 and 2013, 9,627 (6.7%), 1,107 (0.4%), and 2,121 (0.7%) patients were diagnosed with prostate cancer, kidney cancer, and urothelial cancer, respectively. Notably, multivariate analyses revealed that NSAIDs significantly increased the risk of prostate cancer (hazard ratio [HR], 1.35). Also, it was found that aspirin (HR, 1.28) and statin (HR, 1.55) elevated the risk of kidney cancer. No drugs were associated with the risk of urothelial cancer. CONCLUSION: In sum, our study provides the valuable information for the impact of aspirin, NSAID, statin, and COX-2 inhibitor on the risk of prostate, kidney, and urothelial cancer development and its survival outcomes.

Clinicopathologic and Oncological Outcomes in Korean Men With Advanced Metastatic Testicular Cancer Undergoing Postchemotherapeutic Retroperitoneal Lymph Node Dissection

PURPOSE: To evaluate the clinicopathologic and oncological outcomes of advanced metastatic testicular cancer in Korean men who underwent retroperitoneal lymph node dissection (RPLND) following chemotherapy. MATERIALS AND METHODS: Data of 26 patients with testicular cancer who underwent RPLND after chemotherapy at 2 hospitals in Korea between September 2004 and June 2016 were retrospectively analyzed. Clinical and histopathological variables such as stage of the testicular cancer, age of the patients during surgery, size of the retroperitoneal lymph nodes (RPLNs), histopathological results, duration and complications related to the surgery, cancer recurrence, and mortality were analyzed. RESULTS: During testicular surgery, the T stage was pT1, pT2, and pT3 in 50% (n=13), 26.9% (n=7), and 15.3% (n=4) of the patients, respectively. Mixed germ cell tumor was the most common finding, seen in 73.1% (n=19) of patients. The indications for RPLND were residual lymph nodes after chemotherapy, 84.6% (n=22); and disease progression and remission, 7.7% (n=2). Pathological analysis revealed viable tumors in 19.2% of patients (n=5), necrotic/fibrotic tissue in 42.3% (n=11), and teratoma in 34.6% (n=9). Intraoperative and postoperative complications occurred in 23.1% (n=6) and 19.2% of patients (n=5). The median duration of follow-up was 27.5 months (interquartile range, 1.3–108.2 months); 11.5% (n=3) patients had recurrence, and 3.8% (n=1) died of progressive metastatic testicular cancer. CONCLUSIONS: Viable germ cell tumors were present in 19.2% of patients with testicular cancer who underwent RPLND after chemotherapy. This is the first study of its kind in the Korean population.

Development of Decision Support Formulas for the Prediction of Bladder Outlet Obstruction and Prostatic Surgery in Patients With Lower Urinary Tract Symptom/Benign Prostatic Hyperplasia: Part I, Development of the Formula and its Internal Validation / 대한배뇨장애요실금학회지

PURPOSE: As the elderly population increases, a growing number of patients have lower urinary tract symptom (LUTS)/benign prostatic hyperplasia (BPH). The aim of this study was to develop decision support formulas and nomograms for the prediction of bladder outlet obstruction (BOO) and for BOO-related surgical decision-making, and to validate them in patients with LUTS/BPH. METHODS: Patient with LUTS/BPH between October 2004 and May 2014 were enrolled as a development cohort. The available variables included age, International Prostate Symptom Score, free uroflowmetry, postvoid residual volume, total prostate volume, and the results of a pressure-flow study. A causal Bayesian network analysis was used to identify relevant parameters. Using multivariate logistic regression analysis, formulas were developed to calculate the probabilities of having BOO and requiring prostatic surgery. Patients between June 2014 and December 2015 were prospectively enrolled for internal validation. Receiver operating characteristic curve analysis, calibration plots, and decision curve analysis were performed. RESULTS: A total of 1,179 male patients with LUTS/BPH, with a mean age of 66.1 years, were included as a development cohort. Another 253 patients were enrolled as an internal validation cohort. Using multivariate logistic regression analysis, 2 and 4 formulas were established to estimate the probabilities of having BOO and requiring prostatic surgery, respectively. Our analysis of the predictive accuracy of the model revealed area under the curve values of 0.82 for BOO and 0.87 for prostatic surgery. The sensitivity and specificity were 53.6% and 87.0% for BOO, and 91.6% and 50.0% for prostatic surgery, respectively. The calibration plot indicated that these prediction models showed a good correspondence. In addition, the decision curve analysis showed a high net benefit across the entire spectrum of probability thresholds. CONCLUSIONS: We established nomograms for the prediction of BOO and BOO-related prostatic surgery in patients with LUTS/BPH. Internal validation of the nomograms demonstrated that they predicted both having BOO and requiring prostatic surgery very well.

Development of Decision Support Formulas for the Prediction of Bladder Outlet Obstruction and Prostatic Surgery in Patients With Lower Urinary Tract Symptom/Benign Prostatic Hyperplasia: Part II, External Validation and Usability Testing of a Smartphone A / 대한배뇨장애요실금학회지

PURPOSE: We aimed to externally validate the prediction model we developed for having bladder outlet obstruction (BOO) and requiring prostatic surgery using 2 independent data sets from tertiary referral centers, and also aimed to validate a mobile app for using this model through usability testing. METHODS: Formulas and nomograms predicting whether a subject has BOO and needs prostatic surgery were validated with an external validation cohort from Seoul National University Bundang Hospital and Seoul Metropolitan Government-Seoul National University Boramae Medical Center between January 2004 and April 2015. A smartphone-based app was developed, and 8 young urologists were enrolled for usability testing to identify any human factor issues of the app. RESULTS: A total of 642 patients were included in the external validation cohort. No significant differences were found in the baseline characteristics of major parameters between the original (n=1,179) and the external validation cohort, except for the maximal flow rate. Predictions of requiring prostatic surgery in the validation cohort showed a sensitivity of 80.6%, a specificity of 73.2%, a positive predictive value of 49.7%, and a negative predictive value of 92.0%, and area under receiver operating curve of 0.84. The calibration plot indicated that the predictions have good correspondence. The decision curve showed also a high net benefit. Similar evaluation results using the external validation cohort were seen in the predictions of having BOO. Overall results of the usability test demonstrated that the app was user-friendly with no major human factor issues. CONCLUSIONS: External validation of these newly developed a prediction model demonstrated a moderate level of discrimination, adequate calibration, and high net benefit gains for predicting both having BOO and requiring prostatic surgery. Also a smartphone app implementing the prediction model was user-friendly with no major human factor issue.

Conditional Survival and Associated Prognostic Factors in Patients with Upper Tract Urothelial Carcinoma after Radical Nephroureterectomy: A Retrospective Study at a Single Institution / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study is to evaluate the changes of conditional survival (CS) probabilities and to identify the prognostic parameters that significantly affect CS over time post-surgery in upper tract urothelial carcinoma (UTUC) patients. MATERIALS AND METHODS: A total of 330 patients were examined in the final analysis. Primary end point was conditional cancer-specific survival (CSS), overall survival (OS), and intravesical recurrence-free survival (IVRFS) after surgery. The Kaplan-Meier method was used for calculation of CS. Cox regression hazard ratio model was used to determine the predictors of CS. RESULTS: UTUC patients who had already survived 5 years after radical nephroureterectomy had a more favorable CS probability in all given survivorships compared to those with shorter survival times. Patients with unfavorable pathologic features showed a higher increment of 5-year conditional CSS and OS compared to their counterparts. For 5-year conditional CSS, several factors, including high-grade tumor, lymphovascular invasion, and tumor location showed significant association with risk elevation over time. Only age remained as a predictor of 5-year conditional OS with increased risk in all given survivorships. For 5-year IVRFS, no variables remained as significant predictive factors over time after surgery. CONCLUSION: Our study provides valuable information for practical survival estimation and relevant prognostic factors for patients with UTUC after surgery.

The Characteristics of Recurrent Upper Tract Urothelial Carcinoma after Radical Nephroureterectomy without Bladder Cuff Excision

PURPOSE: To investigate oncological outcomes based on bladder cuff excision (BCE) during radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) and to provide clinical evidence of tumor recurrence in patients without BCE. MATERIALS AND METHODS: We retrospectively collected data of 372 consecutive patients who underwent RNU at our institution from May 1989 through October 2010. After excluding some data, we reviewed 336 patients for the analysis. RESULTS: Of the patients who underwent RNU with BCE (n=279, 83.0%) and without BCE (n=57, 17.0%), patients without BCE had poorer cancer-specific and overall survival rates. Among 57 patients without BCE, 35 (61.4%) experienced tumor recurrence. Recurrence at the remnant ureter resulted in poor oncological outcomes compared to those in patients with bladder recurrence, but better outcomes were observed compared to recurrence at other sites. No significant predictors for tumor recurrence at the remnant ureter were identified. In patients without BCE, pathological T stage [hazard ratio (HR), 5.73] and lymphovascular invasion (HR, 3.65) were independent predictors of cancer-specific survival, whereas age (HR, 1.04), pathological T stage (HR, 5.11), and positive tumor margin (HR, 6.50) were independent predictors of overall survival. CONCLUSION: Patients without BCE had poorer overall and cancer-specific survival after RNU than those with BCE. Most of these patients experienced tumor recurrence at the remnant ureter and other sites. Patients with non-organ confined UTUC after RNU without BCE may be considered for adjuvant chemotherapy with careful follow-up.

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study

PURPOSE: To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. MATERIALS AND METHODS: Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. RESULTS: Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4+/-13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. CONCLUSIONS: RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures.