Efficacy and Safety of Human Bone Marrow-Derived Mesenchymal Stem Cells according to Injection Route and Dose in a Chronic Kidney Disease Rat Model

Background and Objectives@#We compared the efficacy and safety of human bone marrow-derived mesenchymal stem cells (hBMSC), delivered at different doses and via different injection routes in an animal model of chronic kidney disease. @*Methods@#and Results: A total of ninety 12-week-old rats underwent 5/6 nephrectomy and randomized among nine groups: sham, renal artery control (RA-C), tail vein control (TV-C), renal artery low dose (RA-LD) (0.5×10 6 cells), renal artery moderate dose (RA-MD) (1.0×10 6 cells), renal artery high dose (RA-HD) (2.0×10 6 cells), tail vein low dose (TV-LD) (0.5×10 6 cells), tail vein moderate dose (TV-MD) (1.0×10 6 cells), and tail vein high dose (TV-HD) (2.0×10 6 cells). Renal function and mortality of rats were evaluated after hBMSC injection. Serum blood urea nitrogen was significantly lower in the TV-HD group at 2 weeks (p＜0.01), 16 weeks (p＜0.05), and 24 weeks (p＜0.01) than in the TV-C group, as determined by one-way ANOVA. Serum creatinine was significantly lower in the TV-HD group at 24 weeks (p＜0.05). At 8 weeks, creatinine clearance was significantly higher in the TV-MD and TV-HD groups (p＜0.01, p＜0.05) than in the TV-C group. In the safety evaluation, we observed no significant difference among the groups. @*Conclusions@#Our findings confirm the efficacy and safety of high dose (2×10 6 cells) injection of hBMSC via the tail vein.

Vocal Fold Augmentation: Current Review / 대한이비인후과학회지

Glottic closure is essential for vocalization and airway protection. Several pathological conditions cause glottic insufficiency, such as vocal fold paralysis and presbylarynx, which is the age-related atrophy of laryngeal muscle. Injection laryngoplasty is common technique to treat glottic insufficiency, because it can be easily and inexpensively performed in an outpatient setting. Different injection material should be selected according to the purpose and patient condition before the procedure. Ideal material for injection laryngoplasty must be biocompatible, and the injected volume should be maintained for the desired duration without migration. Further, it will be better if it could be easily injected and removed. In this article, we reviewed the published research related to material for the injection laryngoplasty and tried to think about the limitations of current studies and the future direction of treatment.

Apalutamide for patients with metastatic castrationsensitive prostate cancer in East Asia: a subgroup analysis of the TITAN trial / 亚洲男科学杂志(英文版)

Ethnicity might be associated with treatment outcomes in advanced prostate cancer. This study aimed to evaluate the efficacy and safety of androgen deprivation therapy (ADT) combined with apalutamide in East Asians with metastatic castration-sensitive prostate cancer (mCSPC). The original phase 3 Targeted Investigational Treatment Analysis of Novel Anti-androgen (TITAN) trial was conducted at 260 sites in 23 countries. This subgroup analysis included patients enrolled in 62 participating centers in China, Japan, and Korea. Radiographic progression-free survival (PFS), time to prostate-specific antigen (PSA) progression, and PSA changes from baseline were compared between groups in the East Asian population. The intent-to-treat East Asian population included 111 and 110 participants in the apalutamide and placebo groups, respectively. The 24-month radiographic PFS rates were 76.1% and 52.3% in the apalutamide and placebo groups, respectively (apalutamide vs placebo: hazard ratio [HR] = 0.506; 95% confidence interval [CI], 0.302-0.849; P = 0.009). Median time to PSA progression was more favorable with apalutamide than placebo (HR = 0.210; 95% CI, 0.124-0.357; P < 0.001). Median maximum percentages of PSA decline from baseline were 99.0% and 73.9% in the apalutamide and placebo groups, respectively. The most common adverse event (AE) was rash in the apalutamide group, with a higher rate than that in the placebo group (37.3% vs 9.1%). The most common grade 3 or 4 AEs were rash (12 [10.9%]) and hypertension (12 [10.9%]) for apalutamide. The efficacy and safety of apalutamide in the East Asian subgroup of the TITAN trial are consistent with the global results.

External Validation of the Long Short-Term Memory Artificial Neural Network-Based SCaP Survival Calculator for Prediction of Prostate Cancer Survival / Journal of the Korean Cancer Association, 대한암학회지

Decision-making for treatment of newly diagnosed prostate cancer (PCa) is complex due to the multiple initial treatment modalities available. We aimed to externally validate the SCaP (Severance Study Group of Prostate Cancer) Survival Calculator that incorporates a long short-term memory artificial neural network (ANN) model to estimate survival outcomes of PCa according to initial treatment modality. Materials and Methods The validation cohort consisted of clinicopathological data of 4,415 patients diagnosed with biopsy-proven PCa between April 2005 and November 2018 at three institutions. Area under the curves (AUCs) and time-to-event calibration plots were utilized to determine the predictive accuracies of the SCaP Survival Calculator in terms of progression to castration-resistant PCa (CRPC)–free survival, cancer-specific survival (CSS), and overall survival (OS). Results Excellent discrimination was observed for CRPC-free survival, CSS, and OS outcomes, with AUCs of 0.962, 0.944, and 0.884 for 5-year outcomes and 0.959, 0.928, and 0.854 for 10-year outcomes, respectively. The AUC values were higher for all survival endpoints compared to those of the development cohort. Calibration plots showed that predicted probabilities of 5-year survival endpoints had concordance comparable to those of the observed frequencies. However, calibration performances declined for 10-year predictions with an overall underestimation. Conclusion The SCaP Survival Calculator is a reliable and useful tool for determining the optimal initial treatment modality and for guiding survival predictions for patients with newly diagnosed PCa. Further modifications in the ANN model incorporating cases with more extended follow-up periods are warranted to improve the ANN model for long-term predictions.

Serum Testosterone Level as Possible Predictive Marker for Prognosis in Metastatic Castration-Resistant Prostate Cancer Patients Treated With Enzalutamide

Purpose@#This study aimed to evaluate the impact of serum testosterone level before enzalutamide treatment in metastatic castration-resistant prostate cancer (mCRPC) for antitumor outcomes. @*Materials and Methods@#Single-center, retrospective study including patients that treated with enzalutamide for mCRPC before and after docetaxel chemotherapy. Clinicopathological parameters including serum testosterone at initial enzalutamide use were examined. Prostate-specific antigen (PSA) response, progression-free survival (PFS), and cancer-specific survival (CSS) were the outcomes of interest. Logistic-regression analysis was done for discovering odds for PSA response. Cox-proportional model was applied for risk stratification for progression and cancer-specific death. @*Results@#A total of 228 patients with mCRPC, treated with enzalutamide, both prechemotherapy and postchemotherapy, between 2011 and 2019 were included. One hundred sixty-two of patients (71.1%) experienced PSA decline over 50%. Median PFS and CSS were 5.4 and 13.2 months, respectively. Serum testosterone at initial enzalutamide use was the noble predictor for progression (hazard ratio [HR], 0.409; p=0.020) and cancer-specific death (HR, 0.454; p=0.033) in postchemotherapy group. No significant effect of serum testosterone in prechemotherapy group was detected. Time to CRPC, high-metastatic burden revealed as risk factors for PSA response, PFS, and CSS, both in prechemotherapy and postchemotherapy group. @*Conclusions@#High testosterone level at commencement of enzalutamide treatment was associated with a good prognosis in postdocetaxel setting, but not related to oncological outcomes in chemotherapy-naïve patients.

Does intraoperative frozen section really predict significant positive surgical margins after robot-assisted laparoscopic prostatectomy? A retrospective study / 亚洲男科学杂志(英文版)

We investigated the relationship between positive surgical margin (PSM)-related factors and biochemical recurrence (BCR) and the ability of intraoperative frozen sections to predict significant PSM in patients with prostate cancer. The study included 271 patients who underwent robot-assisted laparoscopic prostatectomy with bilateral nerve sparing and maximal urethral preservation. Intraoperative frozen sections of the periurethra, dorsal vein, and bladder neck were analyzed. The ability of PSM-related factors to predict BCR and significant PSM was assessed by logistic regression. Of 271 patients, 108 (39.9%) had PSM and 163 (60.1%) had negative margins. Pathologic Gleason score ≥8 (18.9% vs 7.5%, P = 0.015) and T stage ≥T3a (51.9%vs 24.6%, P < 0.001) were significantly more frequent in the PSM group. Multivariate analysis showed that Gleason pattern ≥4 (vs <4; hazard ratio: 4.386; P = 0.0004) was the only significant predictor of BCR in the PSM cohort. Periurethral frozen sections had a sensitivity of 83.3% and a specificity of 84.2% in detecting PSM with Gleason pattern ≥4. Multivariate analysis showed that membranous urethra length (odds ratio [OR]: 0.79, P = 0.0376) and extracapsular extension of the apex (OR: 4.58, P = 0.0226) on magnetic resonance imaging (MRI) and positive periurethral tissue (OR: 17.85, P < 0.0001) were associated with PSM of the apex. PSM with Gleason pattern ≥4 is significantly predictive of BCR. Intraoperative frozen sections of periurethral tissue can independently predict PSM, whereas sections of the bladder neck and dorsal vein could not. Pathologic examination of these samples may help predict significant PSM in patients undergoing robot-assisted laparoscopic prostatectomy with preservation of functional outcomes.

External Validation of the Long Short-Term Memory Artificial Neural Network-Based SCaP Survival Calculator for Prediction of Prostate Cancer Survival / Journal of the Korean Cancer Association, 대한암학회지

Decision-making for treatment of newly diagnosed prostate cancer (PCa) is complex due to the multiple initial treatment modalities available. We aimed to externally validate the SCaP (Severance Study Group of Prostate Cancer) Survival Calculator that incorporates a long short-term memory artificial neural network (ANN) model to estimate survival outcomes of PCa according to initial treatment modality. Materials and Methods The validation cohort consisted of clinicopathological data of 4,415 patients diagnosed with biopsy-proven PCa between April 2005 and November 2018 at three institutions. Area under the curves (AUCs) and time-to-event calibration plots were utilized to determine the predictive accuracies of the SCaP Survival Calculator in terms of progression to castration-resistant PCa (CRPC)–free survival, cancer-specific survival (CSS), and overall survival (OS). Results Excellent discrimination was observed for CRPC-free survival, CSS, and OS outcomes, with AUCs of 0.962, 0.944, and 0.884 for 5-year outcomes and 0.959, 0.928, and 0.854 for 10-year outcomes, respectively. The AUC values were higher for all survival endpoints compared to those of the development cohort. Calibration plots showed that predicted probabilities of 5-year survival endpoints had concordance comparable to those of the observed frequencies. However, calibration performances declined for 10-year predictions with an overall underestimation. Conclusion The SCaP Survival Calculator is a reliable and useful tool for determining the optimal initial treatment modality and for guiding survival predictions for patients with newly diagnosed PCa. Further modifications in the ANN model incorporating cases with more extended follow-up periods are warranted to improve the ANN model for long-term predictions.

Construction of a Retrospective Cohort to Observe 10-Year Urologic Cancer Treatment Trends at the Biggest Medical Center of South Korea

Purpose@#To construct a urologic cancer database using a standardized, reproducible method, and to assess preliminary characteristics of this cohort. @*Materials and Methods@#Patients with prostate, bladder, and kidney cancers who were enrolled with diagnostic codes in the electronic medical record (EMR) at Asan Medical Center from 2007–2016 were included. Research Electronic Data Capture (REDCap) was used to design the Asan Medical Center-Urologic Cancer Database (AMC-UCD). The process included developing a data dictionary, applying branching logic, mapping clinical data warehouse structures, alpha testing, clinical record summary testing, creating “standards of procedure,” importing data, and entering data. Descriptive statistics were used to identify rates of surgeries and numbers of patients. @*Results@#Clinical variables (n=407) were selected to develop a data dictionary from REDCap. In total, 20,198 urologic cancer patients visited our institution from 2007–2016 (bladder cancer, 4,616; kidney cancer, 5,750; prostate cancer, 10,330). The overall numbers of patients and surgeries increased over time, with robotic surgeries rapidly growing over a decade. The most common treatment for urologic cancer was surgery, followed by chemotherapy and radiation therapy. @*Conclusions@#Using a standardized method, the AMC-UCD fosters multidisciplinary research. This constructed database provides access to clinical statistics to effectively assist research. Preliminary data should be refined through EMR chart review. The successful organization of data from 2007–2016 provides a framework for future periods of investigation and prospective models.

Utility of Urinalysis as a Follow-up Surveillance Tool in Nonmuscle Invasive Bladder Cancer

Purpose@#To evaluate the association between microscopic hematuria (MH) detected by surveillance urinalysis and cancer recurrence in nonmuscle invasive bladder cancer (NMIBC) patients. @*Materials and Methods@#A total of 1,082 NMIBC patients who underwent transurethral resection of bladder tumor (TURB) procedures at Asan Medical Center between January 2017 and December 2019 were included. We retrospectively reviewed the follow-up data for these cases including cystoscopy, urinalysis, and urine cytology. The association between urine testing and cancer recurrence was assessed by both univariable and multivariable logistic regression analysis. @*Results@#The study patients had a median age of 68 years (interquartile range, 60–75 years) and comprised 898 men and 184 women. Among the 1,428 TURB procedures conducted in this series, 548 of the lesions (38.4%) were diagnosed as low-grade and 880 (61.6%) as highgrade cancers. A total of 3,309 follow-up cystoscopies were conducted during the study period and were divided into high-grade (HG) (2,011 cases) and low-grade (LG) (1,298 cases) groups according to the latest TURB pathology. MH was found to have a statistically significant association with NMIBC recurrence in both the LG (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.107–2.223; p=0.011) and HG (OR, 1.90; 95% CI, 1.434–2.517; p<0.001) groups. @*Conclusions@#Urinalysis during follow-up may provide important information on cancer recurrence in NMIBC patients.

Subcutaneous Interleukin-2 Monotherapy for Metastatic Renal Cell Carcinoma in Korean Patients

Purpose@#This study was a prospective single-arm clinical trial aimed at assessing the efficacy and toxicity of subcutaneous interleukin (IL)-2 monotherapy in patients with metastatic renal cell carcinoma (RCC). @*Materials and Methods@#We enrolled 26 patients with metastatic RCC in this multicenter controlled trial. The patients received subcutaneous injections of recombinant IL-2 (BMI-rh-IL2, an aldesleukin biosimilar, BMIKOREA Co., Ltd.) in 5-week cycles. In the first week, the patients received a subcutaneous IL-2 loading dose of 18×106 IU once on treatment days 1–5, followed by 2 days of rest. In the following 3 weeks, they received a dose of 18×106 IU via subcutaneous injection once on treatment days 1 and 2. Then, the patients received a dose of 9×106 IU via subcutaneous injection once on treatment days 3, 4, and 5, followed by 2 days of rest. The primary end point was the objective response rate; the secondary end points were progressionfree survival (PFS) and safety. @*Results@#Overall, 22 patients were included in the final per-protocol analysis. The objective response and the disease control rates were 13.64% (3 of 22), and 90.9% (20 of 22), respectively. The mean PFS was 5.55 months (95% confidence interval, 2.71–8.4). The proportion of patients who experienced a treatment-related grade 3 or 4 adverse event was 3.85% (1 of 26). There were no treatment-related deaths. @*Conclusions@#In this study, the subcutaneous IL-2 monotherapy regimen demonstrated efficacy and safety comparable to those reported in previous studies of subcutaneous IL-2 monotherapy and was effective in Korean patients with metastatic RCC.

Risk Factors Leading to Radical Cystectomy in Patients Who Had Undergone Nephroureterectomy

Purpose@#To identify the risk factors leading to radical cystectomy in patients who had undergone nephroureterectomy (NUx). @*Materials and Methods@#We retrospectively reviewed the medical records of patients with upper tract urothelial carcinoma who underwent NUx during 2011–2019 and excluded patients with metastatic cancer. In total 646 patients were included in this study; of these, 532 had no previous bladder cancer history. Follow-up was performed every 3 months for 2 years after NUx was administered, and recurrence was confirmed using cystoscopy, urine cytology, computed tomography, and chest radiography. Bladder recurrence was confirmed through biopsy, urine cytology, or radiologic examination. Univariate and multivariate Cox regression analyzes were performed for statistical analysis of risk factors leading to radical cystectomy in patients undergoing NUx. @*Results@#Lymphovascular invasion (LVI) (hazard ratio [HR], 4.728; 95% confidence interval [CI], 1.463–15.570; p=0.011), previous transurethral resection of bladder tumor history (HR, 3.825; 95% CI, 1.164–12.571; p=0.027), and intravesical recurrence (IVR) within 6 months (HR, 3.733; 95% CI, 1.091–12.778; p=0.036) in patients undergoing NUx are predictors of radical cystectomy implementation. In a multivariate analysis of patients without bladder cancer history, bladder recurrence was identified as a predictor of radical cystectomy implementation, if it occurred within 6 months of NUx (HR, 8.608; 95% CI, 1.545–47.976; p=0.014). @*Conclusions@#LVI and IVR within 6 months and previous bladder cancer history are factors that can predict the need for radical cystectomy after NUx. Even in patients without bladder cancer history, early bladder recurrence within 6 months is a major predictor of radical cystectomy.

Management of Patients With Advanced Prostate Cancer: Establishment ofTreatment Guidelines Through Prostate Cancer Summit (PCAS) 2016Composed of Korean Prostate Cancer Experts

Purpose@#The Advanced Prostate Cancer Consensus Conference (APCCC) 2015 was based on topics withcontroversy in the field of advanced prostate cancer. To understand the Korean urologists perspective regardingthe issues, we have conducted a questionnaire named Prostate Cancer Summit (PCAS) 2016, with 9 importantsubtopics. @*Materials and Methods@#Total 9 subtopics have been decided and questions were developed regarding eachsubtopic. The questions were based on that of APCCC 2015 and translated into Korean for better understanding.Total 51 panelists have voted online on 85 different questions. @*Results@#The survey concluded that testosterone should be measured as a diagnostic criterion for castrationresistance prostate cancer (CRPC) and that consensus was reached on issues such as the use of androgenreceptor pathway inhibitors in the treatment of predocetaxel and postdocetaxel in CRPC patients. In addition,76% of the participants agreed that imaging tests were needed before new treatment in CRPC patients, anda majority of participants agreed that periodic imaging tests are necessary regardless of symptoms during treatmentfor CRPC. However, some issues, such as the use of prostate-specific antigen-based triggers for remediationin CRPC patients, the endocrine manipulation in nonmetastatic CRPC patients, and the onset of treatment inasymptomatic metastatic CRPC patients, were not agreed. @*Conclusions@#The results from PCAS 2016 has addressed some of the issues with controversy. Although thevoting results are subjective, it will help guide treatment decisions in topics with less evidence.

Cause of Mortality after Radical Prostatectomy and the Impact of Comorbidity in Men with Prostate Cancer: A Multi-institutional Study in Korea / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study aimed to examine the causes of death in Korean patients who underwent radical prostatectomy for prostate cancer and investigate the relationship between comorbidity and mortality. @*Materials and Methods@#We conducted a retrospective multicenter cohort study including 4,064 consecutive patients who had prostate cancer and underwent radical prostatectomy between January 1998 and June 2013. The primary endpoint of this study was all-cause mortality, and the secondary endpoints were cancer-specific mortality (CSM) and other-cause mortality (OCM). Charlson comorbidity index (CCI) was calculated to assess the comorbidities of each patient. @*Results@#Of 4,064 patients, 446 (11.0%) died during follow-up. The cause of death was prostate cancer in 132 patients (29.6%), other cancers in 121 patients (27.1%), and vascular disease in 57 patients (12.8%) in our cohort. The overall 10-year CSM rate was lower than the OCM rate (4.6% vs. 10.5%). The 10-year CSM rate was lower than the OCM rate in low- to intermediate-risk group patients (1.2% vs. 10.6%), whereas they were similar in high-risk group patients (11.8% vs. 10.1%). In the multivariable analysis, CCI was independently associated with all-cause mortality after radical prostatectomy, regardless of age and pathologic features. @*Conclusion@#Death from prostate cancer was rare in Korean men who underwent radical prostatectomy. Clinicians should be aware of the possibility of overtreatment of low-risk prostate cancer in men with significant comorbidity. Our findings may help to facilitate counseling and plan management in this patient group.

A Review of Three-Dimensional Printing Technology for Medical Applications

Three-dimensional (3D) printing technology, with additive manufacturing, can aid in the production of various kinds of patient-specific medical devices and implants in medical fields, which cannot be covered by mass production systems for producing conventional devices/implants. The simulator-based medical image demonstrates the anatomical structure of the disease, which can be used for education, diagnosis, preparation of treatment plan and preoperative surgical guide, etc. The surgical guide is used as a patient-specific medical device for guiding incision, resection, insertion, and marking. As 3D printers can output materials that can be inserted into the human body, the patient-specific implant device that reflects the patient's anatomy and surgical plan could be of relevance. In addition, patient-specific aids, including gibs, splints, prostheses, and epitheses, could be used for a better outcome. Finally, bio-printing is also used to cultivate cells to produce functional artificial tissues.

Hypoxic Preconditioned Mesenchymal Stromal Cell Therapy in a Rat Model of Renal Ischemia-reperfusion Injury: Development of Optimal Protocol to Potentiate Therapeutic Efficacy

Although previous and ongoing clinical studies have used stromal cells during renal ischemia-reperfusion injury (IRI), there is little consensus regarding the optimal protocol. We aimed to optimize the protocol for hypoxic preconditioned human bone marrow-derived mesenchymal stromal cell (HP-hBMSC) therapy in a rat model of renal IRI. We determined the optimal injection route (renal arterial, renal parenchymal, and tail venous injection), dose (low-dose: 1×10⁶, moderate-dose: 2×10⁶, and high-dose: 4×10⁶), and injection period (pre-, concurrent-, and post-IRI). During optimal injection route study, renal arterial injections significantly reduced the decreasing glomerular filtration rate (GFR), as compared to GFRs for the IRI control group, 2 and 4 days after IRI. Therapeutic effects and histological recoveries were the greatest in the group receiving renal arterial injections. During the dose finding study, high-dose injections significantly reduced the decreasing GFR, as compared to GFRs for the IRI control group, 3 days after IRI. Therapeutic effects and histological recoveries were the greatest in the high-dose injection group. While determining the optimal injection timing study, concurrent-IRI injection reduced elevated serum creatinine levels, as compared to those of the IRI control group, 1 day after IRI. Pre-IRI injection significantly reduced the decreasing GFR, as compared with GFRs for the IRI control group, 1 day after IRI. Therapeutic effects and histological recoveries were the greatest in the concurrent-IRI group. In conclusion, the concurrent-IRI administration of a high dose of HP-hBMSC via the renal artery leads to an optimal recovery of renal function after renal IRI.

Vocal Fold Regeneration: Current Review / 대한이비인후과학회지

The extracellular matrix (ECM) of the vocal folds cannot be replaced after severe injury, but heal as scars. Scarred vocal folds cause voice problems. Many treatments have been attempted for vocal fold scarring, but their effectiveness is limited because the ECM composition does not normalize. Therefore, until now the prevention of scar formation has been important. In the field of regenerative medicine, cell therapies such as stem cell transplantation, and the implantation of several types of growth factors with or without scaffolds have been used. In this article, we reviewed the published research related to vocal fold regeneration and tried to think about the limitations of current studies and the future direction of treatment.

Comparison of Prognosis in Types 1 and 2 Papillary Renal Cell Carcinoma and Clear Cell Renal Cell Carcinoma in T1 Stage

PURPOSE: We compared subtypes of papillary renal cell carcinoma (pRCC; types 1 and 2) and clear cell renal cell carcinoma (ccRCC) in patients with T1-stage RCC to analyze the impact of the subtype on oncological outcomes. MATERIALS AND METHODS: This paper reviewed 75 patients with pRCC and 252 patients with ccRCC at T1-stage from 1998–2012. Thus, we assessed the impact of subtype on oncologic outcomes among patients with T1-stage RCC. We used Kaplan-Meier analysis to estimate the overall survival and recurrence-free survival The median follow-up duration was 95 months (interquartile range, 75.4–119.3 months). RESULTS: The 5-year recurrence-free survivals of pRCC and ccRCC were 95.4% and 97.6%, respectively. pRCC is worse than ccRCC in terms of recurrence-free survival (p=0.008) and there was no significant difference in the overall survival between pRCC and ccRCC (p=0.32). In addition, there was no significant statistical difference between type 1 pRCC and type 2 pRCC in terms of either recurrence-free survival (p=0.526) or overall survival (p=0.701). Age (hazard ratio [HR], 1.069; p < 0.001) and recurrence (HR, 4.93; p < 0.001) were predictors of overall survival. Only tumor size (HR, 1.071; p=0.004) was predictors in the case of cancer specific survival in the multivariate analysis. CONCLUSIONS: Among patients with T1-stage RCC, recurrence after surgery was more common in pRCC than ccRCC. The subtype of pRCC (types 1 and 2) had no impact on the recurrence-free survival or overall survival.

Impact of Histologic Variants of Bladder Cancer on Oncology Outcome After Radical Cystectomy

PURPOSE: To evaluate the oncological outcome of histologic variants in bladder cancer patients who underwent radical cystectomy. MATERIALS AND METHODS: We identified 393 bladder cancer patients who underwent radical cystectomy at single center between January 2007 and August 2014. Patients were divided into 4 groups according to histologic types: pure urothelial cell carcinoma (UC) and squamous, micropapillary, and other variants. Kaplan-Meier analysis was performed to assess recurrence-free (RFS) and overall survivals (OS). The patients were divided into those with pathologic stage and nodal status. RESULTS: Among 393 bladder cancer patients, squamous, micropapillary histologic variants were observed in 38 (9.7%), 26 (6.6%), respectively, whereas 39 had other variant types. Stage T3 cancer occurred in more patients with histologic variant compared with those with pure UC. Pathologic positive nodal status was also frequently found in the histologic variant groups. Subgroup analysis according to T stage and nodal status showed no significant difference in RFS and OS. On multivariate analysis, pathologic T stage (stage T2: hazard ratio [HR], 2.75; 95% confidence interval [CI], 1.34–5.63; p=0.005; stage ≥T3: HR, 3.20; 95% CI, 1.62–6.30; p=0.001) and nodal status (HR, 1.85; 95% CI, 1.05–2.56; p=0.028) were prognostic factors for RFS. CONCLUSIONS: In patients who underwent radical cystectomy, histologic variants were detected more often at advanced pathologic stage. Although histologic variants have been identified in the radical cystectomy specimen, treatment should be performed according to the pathologic stage.

Preserving Renal Function through Partial Nephrectomy Depends on Tumor Complexity in T1b Renal Tumors

This study aimed to determine patients with T1b renal cell carcinoma (RCC) who could benefit from partial nephrectomy (PN) and method to identify them preoperatively using nephrometry score (NS). From a total of 483 radical nephrectomy (RN)-treated patients and 40 PN-treated patients who received treatment for T1b RCC between 1995 and 2010, 120 patients identified through 1:2 propensity-score matching were included for analysis. Probability of chronic kidney disease (CKD) until postoperative 5-years was calculated and regressed with respect to the surgical method and NS. Median follow-up was 106 months. CKD-probability at 5-years was 40.7% and 13.5% after radical and PN, respectively (P = 0.005). While PN was associated with lower risk of CKD regardless of age, comorbidity, preoperative estimated renal function, the effect was observed only among patients with NS ≤ 8 (P < 0.001) but not in patients with NS ≥ 9 (P = 0.746). Percent operated-kidney volume reduction and ischemia time were similar between the patients with NS ≥ 9 and ≤ 8. In the stratified Cox regression accounting for the interaction observed between the surgical method and the NS, PN reduced CKD-risk only in patients with NS ≤ 8 (hazard ratio [HR], 0.054; P = 0.005) but not in ≥ 9 (HR, 0.996; P = 0.994). In T1b RCC with NS ≥ 9, the risk of postoperative CKD was not reduced following PN compared to RN. Considering the potential complications of PN, minimally invasive RN could be considered with priority in this subgroup of patients.

Three-Dimensional Printing: Basic Principles and Applications in Medicine and Radiology

The advent of three-dimensional printing (3DP) technology has enabled the creation of a tangible and complex 3D object that goes beyond a simple 3D-shaded visualization on a flat monitor. Since the early 2000s, 3DP machines have been used only in hard tissue applications. Recently developed multi-materials for 3DP have been used extensively for a variety of medical applications, such as personalized surgical planning and guidance, customized implants, biomedical research, and preclinical education. In this review article, we discuss the 3D reconstruction process, touching on medical imaging, and various 3DP systems applicable to medicine. In addition, the 3DP medical applications using multi-materials are introduced, as well as our recent results.