Long short-term memory artificial neural network model for prediction of prostate cancer survival outcomes according to initial treatment strategy: development of an online decision-making support system.

PURPOSE: The delivery of precision medicine is a primary objective for both clinical and translational investigators. Patients with newly diagnosed prostate cancer (PCa) face the challenge of deciding among multiple initial treatment modalities. The purpose of this study is to utilize artificial neural network (ANN) modeling to predict survival outcomes according to initial treatment modality and to develop an online decision-making support system. METHODS: Data were collected retrospectively from 7267 patients diagnosed with PCa between January 1988 and December 2017. The analyses included 19 pretreatment clinicopathological covariates. Multilayer perceptron (MLP), MLP for N-year survival prediction (MLP-N), and long short-term memory (LSTM) ANN models were used to analyze progression to castration-resistant PCa (CRPC)-free survival, cancer-specific survival (CSS), and overall survival (OS), according to initial treatment modality. The performances of the ANN and the Cox-proportional hazards regression models were compared using Harrell's C-index. RESULTS: The ANN models provided higher predictive power for 5- and 10-year progression to CRPC-free survival, CSS, and OS compared to the Cox-proportional hazards regression model. The LSTM model achieved the highest predictive power, followed by the MLP-N, and MLP models. We developed an online decision-making support system based on the LSTM model to provide individualized survival outcomes at 5 and 10 years, according to the initial treatment strategy. CONCLUSION: The LSTM ANN model may provide individualized survival outcomes of PCa according to initial treatment strategy. Our online decision-making support system can be utilized by patients and health-care providers to determine the optimal initial treatment modality and to guide survival predictions.

Oncological outcomes after partial vs radical nephrectomy in renal cell carcinomas of ≤7 cm with presumed renal sinus fat invasion on preoperative imaging.

OBJECTIVES: To compare oncological outcomes of partial nephrectomy (PN) and radical nephrectomy (RN) for renal tumours of ≤7 cm in which preoperative imaging reveals potential renal sinus fat invasion (cT3a), as RN is preferred for these tumours due to concerns about high tumour stage. PATIENTS AND METHODS: Among 1137 nephrectomies performed for renal tumours of ≤7 cm from January 2005 to August 2012, 401 solitary cT3a renal cell carcinomas (RCCs) without metastases were analysed. Classification as cT3a included only renal sinus fat invasion, as there were no tumours with suspected perinephric fat invasion. Multivariate models were used to evaluate predictors of recurrence-free survival (RFS) and cancer-specific survival (CSS). RESULTS: There were 34 RCCs (8.5%) with unexpected perinephric fat invasion, but only 77 RCCs (19.2%) were staged as pT3a. During the median follow-up of 43.0 months, recurrence occurred in seven (6.7%) PN cases and 25 (8.4%) RN cases. Six recurred PN cases had positive surgical margins (PSMs). The two cohorts showed equal oncological outcomes for 5-year RFS and CSS. Multivariate analyses showed PSM, pathological T stage, sarcomatoid dedifferentiation, and type of surgery as significant predictors of recurrence. Older age, pathological T stage, and sarcomatoid dedifferentiation were significant predictors of cancer-specific mortality. CONCLUSIONS: Renal tumours of ≤7 cm with presumed renal sinus fat invasion were mostly pT1. PN conferred equivalent oncological outcomes to RN. If clear surgical margins can be obtained, PN should be considered for these tumours, as patients may benefit from renal function preservation.

Prognostic impact of synchronous second primary malignancies on the overall survival of patients with metastatic prostate cancer.

PURPOSE: We determined the prognostic impact of a synchronous second primary malignancy on overall survival in patients with metastatic prostate cancer. Identifying features that stratify the risk of overall survival is critical for judiciously applying definitive therapy. MATERIALS AND METHODS: We retrospectively analyzed the records of 582 consecutive patients with prostate cancer diagnosed with metastasis between May 7, 1998 and August 27, 2011. Patient age, body mass index, ECOG performance status, Charlson comorbidity index, prostate specific antigen, T and N stages, Gleason and ASA® scores, progression to castration resistant prostate cancer, prior local treatments and synchronous second primary malignancies at metastasis were assessed. A synchronous second primary malignancy was defined as a cytologically or histologically proven solid malignancy. Cox proportional hazards regression analysis was done to estimate overall survival by second primary type and evaluate predictive variables. RESULTS: A total of 164 patients (28.1%) had a synchronous second primary malignancy, of which colorectal (9.1%), stomach (7.3%) and lung (7.1%) cancers were the most prevalent types. During a median followup of 34.1 months patients without a synchronous second primary malignancy had a significantly higher overall survival rate than those with lung or stomach cancer. However, men without a second malignancy had outcomes comparable to those in men with colorectal cancer. Clinical stage T4 or greater, ASA score 1 or greater and lung or stomach cancer were independent predictors of overall mortality. CONCLUSIONS: A substantial proportion of patients with metastatic prostate cancer present with a synchronous second primary malignancy. Definitive therapy targeting prostate cancer may confer a limited survival benefit in patients with synchronous lung or stomach cancer.

Transurethral resection of the prostate for patients with Gleason score 6 prostate cancer and symptomatic prostatic enlargement: a risk-adaptive strategy for the era of active surveillance.

OBJECTIVE: To investigate whether transurethral resection of the prostate can be used as both (i) treatment for symptomatic prostatic enlargement in patients with prostate cancer and (ii) a risk-adaptive strategy for reducing prostate-specific antigen levels and broadening the indications of active surveillance. METHODS: We retrospectively reviewed data of 3680 patients who underwent prostate biopsies at a single institution (March 2006 to January 2012). Of 529 men who had Gleason score 6 prostate cancer and were ineligible for active surveillance, 86 (16.3%) underwent transurethral resection of the prostate for symptomatic prostatic enlargement. We assessed how changes in prostate-specific antigen and prostate-specific antigen density influenced the eligibility for active surveillance and the outcome of subsequent therapy. The following active surveillance criteria were used: prostate-specific antigen ≤ 10 ng/ml, prostate-specific antigen density ≤ 0.15, positive cores ≤ 3 and single core involvement ≤ 50%. RESULTS: The median age, pre-operative prostate-specific antigen and prostate volume were 71 years, 6.95 ng/ml, and 45.8 g, respectively. In 82.6% (71/86) of analyzed cases, ineligibility for active surveillance had resulted from elevated prostate-specific antigen level or prostate-specific antigen density. With a median resection of 16.5 g, transurethral resection of the prostate reduced the percentage of prostate-specific antigen and the percentage of prostate-specific antigen density by 34.5 and 50.0%, respectively, making 81.7% (58/71) of the patients eligible for active surveillance. Prostate-specific antigen level remained stabilized in all (21/21) patients maintained on active surveillance without disease progression during the median follow-up of 50.6 months. Among patients who underwent radical prostatectomy, 96.7% (29/30) exhibited localized disease. CONCLUSIONS: Risk-adaptive transurethral resection of the prostate may prevent overtreatment and allay prostate-specific antigen-associated anxiety in patients with biopsy-proven low-grade prostate cancer and elevated prostate-specific antigen. Additional benefits include voiding symptom improvement and the avoidance of curative therapy's immediate side effects.

Prospective measurement of urinary microalbumin in living kidney donor nephrectomy: toward understanding the renal functional recovery period.

PURPOSE: We determined the clinical implications of perioperative urinary microalbumin excretion in relation to renal function after living donor nephrectomy. MATERIALS AND METHODS: Between August 2010 and January 2013, 259 donors undergoing live donor nephrectomy were enrolled in the study. The donor urinary albumin-to-creatinine ratio was measured perioperatively, and changes in perioperative urinary albumin-to-creatinine ratio and the implications of preoperative microalbuminuria (urinary albumin-to-creatinine ratio 30 mg/gm or greater) were investigated. The relationships between perioperative urinary albumin-to-creatinine ratio and recovery of renal function and implantation biopsy histology were also analyzed. RESULTS: Mean ± SD preoperative urinary albumin-to-creatinine ratio was 7.1±12.7 mg/gm. The urinary albumin-to-creatinine ratio was increased after 1 day (24.7±18.9 mg/gm, p <0.001) and stabilized after 1 month (10.3±10.7 mg/gm, p <0.001). Preoperative microalbuminuria was not associated with perioperative estimated glomerular filtration rate during a followup period of 6 months but was associated with histological abnormalities. Donors with a higher urinary albumin-to-creatinine ratio before donation, even in the normal range, consistently had an increased postoperative urinary albumin-to-creatinine ratio. A ROC curve analysis showed that age, preoperative estimated glomerular filtration rate and 1-month postoperative urinary albumin-to-creatinine ratio were highly predictive of delayed recovery of renal function (AUC 0.884, p <0.001). The 1-month postoperative urinary albumin-to-creatinine ratio was associated with delayed recovery of renal function (OR 1.05 for each 0.1 mg/gm increase, p=0.021). CONCLUSIONS: Donors with higher preoperative urinary albumin-to-creatinine ratio levels require close observation because there is a greater possibility of microalbuminuria developing after donation even if the ratio is within the normal range. A higher urinary albumin-to-creatinine ratio was also associated with delayed recovery of renal function and histological abnormalities.

Impact of Charlson comorbidity index varies by age in patients with prostate cancer treated by radical prostatectomy: a competing risk regression analysis.

PURPOSE: To investigate the prognostic impact of the Charlson comorbidity index (CCI) on either cancer-specific mortality (CSM) or other-cause mortality (OCM) according to age in patients with prostate cancer (PC) who underwent radical prostatectomy (RP). METHODS: Data from 336 patients who underwent RP for PC between 1992 and 2005 were analyzed. Variables, including the preoperative prostate-specific antigen (PSA), prostate volume, clinical stage, and pathologic stage, were compared across age groups (<65 or ≥65 years old). Preexisting comorbidities were evaluated by the CCI, and patients were classified into two CCI score categories (0 or ≥1). RESULTS: The median (interquartile range) follow-up period was 96 (85-121) months. Subjects were divided into two subgroups according to age: <65 years (n = 151) or ≥65 years (n = 185). There was no significant difference in PSA, biopsy Gleason sum, body mass index, pathologic stage, or CCI between the two age groups. OCM was significantly associated with the CCI score (P = 0.011). Cumulative incidence estimates obtained from competing risk regression analysis indicated that CCI was not associated with CSM (P = 0.795) or OCM (P = 0.123) in the ≥65-year group. However, in men <65 years, cumulative incidence estimates for OCM were significantly associated with CCI (P = 0.036). CONCLUSIONS: CCI was independently associated with OCM after RP, but only in men <65 years old. CCI was not associated with CSM in either age group. Accordingly, a thorough evaluation of patient's comorbidities is mandatory when considering aggressive surgical treatment, especially in relatively young patients.

Robot-assisted radical prostatectomy in the Korean population: a 5-year propensity-score matched comparative analysis versus open radical prostatectomy.

OBJECTIVES: To compare the oncological outcomes of robot-assisted laparoscopic radical prostatectomy with those of open radical prostatectomy in contemporary Korean prostate cancer patients. METHODS: From a group of 1172 patients consisting of 592 (50.5%) robot-assisted laparoscopic radical prostatectomy and 580 (49.5%) open radical prostatectomy cases carried out between 1992 and 2008, 175 robot-assisted laparoscopic radical prostatectomy cases were matched with an equal number of open radical prostatectomy cases by propensity scoring based on patient age, preoperative prostate-specific antigen, biopsy Gleason score and clinical tumor stage. Competing-risks survival analyses were used to evaluate oncological outcomes, including rates of positive surgical margin, biochemical-recurrence, adjuvant therapy, cancer-specific survival, overall survival and metastasis-free survival during the mean follow up of 58.4 months. RESULTS: Positive surgical margin rates were comparable between robot-assisted laparoscopic radical prostatectomy and open radical prostatectomy cohorts (19.4% vs 21.8%), with comparable rates for all pathological stages and risk subgroups. Positive surgical margin rates according to location were comparable, with the apical margin being the most common location. Robot-assisted laparoscopic radical prostatectomy recovered higher lymph node yields compared with open radical prostatectomy (12.5 vs 3.8; P < 0.001). The robot-assisted laparoscopic radical prostatectomy and the open radical prostatectomy groups showed equal oncological outcomes regarding 5-year biochemical recurrence-free survival (log-rank P = 0.651), metastasis-free survival (log-rank P = 0.876), cancer-specific survival (log-rank P = 0.076) and overall survival (log-rank P = 0.648), respectively. Between groups, there was no difference in the rate of adjuvant therapy, time to first adjuvant therapy failure or in the rate of subsequent secondary treatment. CONCLUSIONS: Robot-assisted laparoscopic radical prostatectomy represents an effective surgical approach for the treatment of prostate cancer in the Korean population, as it provides equivalent oncological outcomes to open radical prostatectomy.

Normal liver elasticity values using acoustic radiation force impulse imaging: a prospective study in healthy living liver and kidney donors.

BACKGROUND AND AIM: Although several studies have investigated the normal range of liver elasticity using acoustic radiation force impulse (ARFI) elastography in healthy volunteers, they could not strictly exclude the morphological and functional liver abnormalities. The aim of this study was to identify the normal range of ARFI velocity by recruiting healthy living liver and kidney donors who passed the full laboratory tests and imaging studies. METHODS: The study prospectively enrolled 108 healthy living liver (n = 42) and kidney donors (n = 66) who were admitted for transplantation between July 2010 to April 2011. None of the subjects had abnormal liver function test and imaging findings including conventional ultrasonography, computed tomography or magnetic resonance imaging. RESULTS: The mean age of the study population (58 men and 50 women) was 35.5 years, and the mean ARFI velocity was 1.07 ± 0.11 m/s (range: 0.79-1.27). ARFI velocity was not significantly different between subjects with body mass index (BMI) < 23.5 kg/m(2) and those with BMI ≥ 23.5 kg/m(2) (1.05 ± 0.12 m/s vs 1.07 ± 0.10 m/s, P = 0.518), nor was it significantly different according to age (P = 0.067) and gender (1.08 ± 0.12 m/s for men vs 1.05 ± 0.11 m/s for women, P = 0.085). Using the 5(th) and 95(th) percentiles, we determined the normal range and mean of ARFI velocity to be 0.85-1.25 m/s and 1.07 ± 0.11 m/s. CONCLUSIONS: We identified the normal range of ARFI velocity as 0.85-1.25 m/s and found that it was not significantly influenced by BMI, gender, and age.

"Normal" liver stiffness values differ between men and women: a prospective study for healthy living liver and kidney donors in a native Korean population.

BACKGROUND AND AIM: Liver stiffness (LS) measurement can distinguish individuals with potential liver disease (LD) from the general population. However, if LS is sex-sensitive, prevalence of LD may be incorrectly estimated when the same reference LS value is applied irrespective of sex. Here, we evaluated whether normal ranges of LS differ between healthy men and women. METHODS: LS was measured in a cohort of healthy living liver and kidney donors, none of whom suffered from diabetes mellitus, hypertension, hepatitis B or C virus infection, heart or liver dysfunction, or metabolic syndrome. Patients with abnormal laboratory findings related to potential LD (platelet count < 150 × 10(3) /µL; aspartate aminotransferase > 40 IU/L; alanine aminotransferase [ALT] > 40 IU/L; albumin < 3.3 g/dL; total bilirubin > 1.2 mg/dL; gamma-glutamyl transpeptidase > 54 IU/L; alkaline phosphatase > 115 IU/L) were excluded. RESULTS: Among 242 patients analyzed, the mean age was 34.1 for men (n = 121) and 40.5 years for women (n = 121) (P < 0.001). Men had a higher mean LS value than women (5.2 ± 1.2 vs 4.8 ± 1.1 kPa/P < 0.001). Multivariate-linear regression analysis identified sex as the only independent factor for LS values (ß = 0.361/P = 0.021). Using the 5th-95th percentiles, we determined normal LS ranges of 3.7-7.0 kPa in men and 3.3-6.8 kPa in women. In subgroups with ALT < 30 IU/L (subgroup-1, n = 216) and ALT < 20 IU/L (subgroup-2, n = 163), men had significantly higher LS values than women (5.2 ± 1.3 vs 4.7 ± 1.1 kPa/P = 0.003 and 5.1 ± 1.2 vs 4.7 ± 1.1 kPa/P = 0.030, respectively), demonstrating an independent sex effect (ß = 0.483/P = 0.003 and ß = 0.389/P = 0.030, respectively). CONCLUSIONS: An independent sex effect on LS values was confirmed. Thus, sex-specific references should be used for effective screening based on LS measurements.

Comparison of pathological outcomes of active surveillance candidates who underwent radical prostatectomy using contemporary protocols at a high-volume Korean center.

OBJECTIVE: We compared contemporary active surveillance protocols based on pathological outcomes in patients who underwent radical prostatectomy. METHODS: We identified the experimental cohort from prostate cancer patients who underwent radical prostatectomy between 2001 and 2011, and who met the inclusion criteria of five published active surveillance protocols, namely Johns Hopkins Medical Institution, University of California at San Francisco, Memorial Sloan-Kettering Cancer Center, University of Miami and Prostate Cancer Research International: Active Surveillance. To compare each protocol, we evaluated the pathological outcomes and calculated the sensitivity, specificity and accuracy for each protocol according to the proportion of organ-confined Gleason≤6 disease. RESULTS: Overall, 376 patients met the inclusion criteria of the active surveillance protocols with 61, 325, 222, 212 and 206 patients meeting the criteria of the Johns Hopkins Medical Institution, University of California at San Francisco, Memorial Sloan-Kettering Cancer Center, University of Miami and Prostate Cancer Research International: Active Surveillance protocols, respectively. The sensitivity and specificity values of the five protocols, respectively, were 0.199 and 0.882 in Johns Hopkins Medical Institution, 0.855 and 0.124 in University of California at San Francisco, 0.638 and 0.468 in Memorial Sloan-Kettering Cancer Center, 0.599 and 0.479 in University of Miami, and 0.609 and 0.527 in Prostate Cancer Research International: Active Surveillance. In terms of both the sensitivity and specificity, Prostate Cancer Research International: Active Surveillance was the most balanced protocol. In addition, Prostate Cancer Research International: Active Surveillance showed a more accurate performance for favourable pathological outcomes than the others. However, using the area under the curve to compare the discriminative ability of each protocol, there were no statistically significant differences. CONCLUSIONS: The contemporary active surveillance protocols showed similar pathological characteristics in patients who had undergone radical prostatectomy. However, we concluded that the Prostate Cancer Research International: Active Surveillance protocol would be most helpful to Korean populations in choosing candidates for active surveillance considering the balance between sensitivity and specificity and the accuracy of diagnosis.

Standardized video-assisted retroperitoneal minilaparotomy surgery for 615 living donor nephrectomies.

To increase the rate of living kidney donation, the long-term safety of nephrectomy must be demonstrated to potential donors. We analyzed long-term donor outcomes and evaluated the standardization of surgical technique. We evaluated 615 donors who underwent Video-assisted minilaparotomy living donor nephrectomy (VLDN) at Yonsei Severance Hospital between 2003 and 2009. Perioperative data and predictors of outcomes were prospectively analyzed. The mean operative time and mean warm ischemia time were 192.7 and 2.2 min, respectively. Mean estimated blood loss was 195.3 ml. The mean post-transplant serum creatinine levels and Modification of Diet in Renal Disease study equation for estimating glomerular filtration rate were 1.1 mg/dl and 68 ml/min/1.73 m(2) , respectively at 5 years after VLDN. The intra-operative and postoperative complication rate were 3.1% and 6.3%, respectively. Delayed renal function, 5-year graft survival, and complication rates of recipients were 1.1%, 98.4%, and 0.4%, respectively. Predictors of operative time were medical history, vessel anomaly, and surgeon experience (>50 cases). The single predictor of intra-operative complications was vessel anomaly. Standardized VLDN is feasible and safe. Our data on long-term outcomes can assist in demonstrating the long-term safety of donor nephrectomy to potential donors. To compare VLDN to other types of donor nephrectomy, a prospective multicenter study must be performed.

Predictors of kidney volume change and delayed kidney function recovery after donor nephrectomy.

PURPOSE: To our knowledge the effects of preoperative kidney volume in living donors on the post-donation change in size and function of the remaining kidney have not been investigated. We studied the association between preoperative kidney volume, and volume change and delayed kidney function recovery in donors. MATERIALS AND METHODS: From 2007 to 2008 we investigated 222 living donors. Kidney volume before and 6 months after surgery was estimated using the voxel count method. We analyzed correlations of kidney volume with patient characteristics, kidney function and actual kidney weight. To identify predictors of the volume increase of the remaining kidney and predictors of delayed kidney function recovery we performed regression analysis. RESULTS: Mean +/- SD total kidney volume was 311.9 +/- 50.6 cc and it correlated with weight, body surface area and kidney function (p <0.001). The mean volume increase in the remaining kidney was 27.6% +/- 9.7% (range 4.5% to 66.1%). Younger age (p <0.001) and lower preoperative volume of the remaining kidney (p = 0.019) were significant predictors of a greater increase in kidney volume on multiple linear regression analysis. Older age (OR 1.07, p <0.001), higher body mass index (OR 1.20, p = 0.008), lower preoperative kidney volume of the remaining kidney (OR 0.98, p = 0.003) and a lower preoperative diethylenetetramine pentaacetic acid glomerular filtration rate in the remaining kidney (OR 0.95, p = 0.017) were significant predictors of delayed kidney function recovery on multiple regression analysis. CONCLUSIONS: Kidney volume measured by the voxel count method was accurate and correlated with kidney function. Preoperative kidney volume is an independent predictor of the volume increase and delayed kidney function recovery in donors that could be used clinically.

What are 'true normal' liver stiffness values using FibroScan?: a prospective study in healthy living liver and kidney donors in South Korea.

AIMS: To identify the normal range of liver stiffness (LS) values by recruiting healthy living liver and kidney donors in South Korea. METHODS: Liver stiffness measurement (LSM) was performed in 69 healthy living liver and kidney donors who were admitted for transplantation. None of the subjects suffered from diabetes mellitus, hypertension, hepatitis B virus infection, hepatitis C virus infection, heart dysfunction, liver dysfunction or metabolic syndrome. RESULTS: LSM failure rate was 2.7%. Among 12 liver donors (17.4%) with available liver histology, eight showed normal liver histology and four showed liver steatosis of <5% of the hepatocytes. The mean age of our study population was 38.9+/-11.9 years (35 men and 34 women), with a mean LS value of 4.6+/-0.5 kPa (range 3.3-5.6 kPa). LS values were not significantly different between men (4.6+/-0.6 kPa) and women (4.5+/-0.5 kPa, P=0.636), nor were they significantly different according to age (P=0.851). Using the fifth and 95th percentiles, we determined the normal range of LS values to be 3.9-5.3 kPa. CONCLUSIONS: We identified the normal range of LS values and found that LS values were not significantly influenced by age and gender.

The feasibility of solo-surgeon living donor nephrectomy: initial experience using video-assisted minilaparotomy surgery.

BACKGROUND: Today, many kinds of surgery are being conducted without human assistants. Living donor nephrectomy (LDN) using video-assisted minilaparotomy surgery (VAM) has been performed by solo-surgeon using Unitrac® (Aesculap Surgical Instrument, Germany). We examined the results from VAM-solo-surgeon living donor nephrectomy (SLDN) and conventional VAM-human-assisted living donor nephrectomy (HLDN). METHODS: Between July 2007 and April 2008, 82 cases of VAM-LDN were performed by two surgeons. From these cases, we randomly assigned 35 cases to undergo solo-surgery (group I) and the other 47 cases to undergo surgery with one human assistant (group II). All VAM-LDN procedures were performed in the same manner. Only the roles of a first assistant were substituted by the Unitrac® in group I. We compared the perioperative and postoperative data, including operative time, estimated blood loss, and hospital stay, between the two groups. We also investigated cases that developed complications. RESULTS: There were no significant differences in the patient demographic data between the two groups (P > 0.05). The mean operative time was 201.9 ± 32.9 min in group I and 202.4 ± 48.3 min in group II (P = 0.954), whereas mean blood loss was 209.7 ± 167.3 ml in group I and 179.6 ± 87.8 ml in group II (P = 0.294). Postoperative hospital stay were 5.4 ± 1.1 days in group I and 5.5 ± 1.6 days in group II (P = 0.813). The incidence of perioperative complications was not significantly different between the two groups. CONCLUSIONS: Our study demonstrates that VAM-SLDN can be performed safely, is economically beneficial, and is comparable to VAM-HLDN in terms of postoperative outcomes.

Trends in the incidence of benign pathological lesions at partial nephrectomy for presumed renal cell carcinoma in renal masses on preoperative computed tomography imaging: a single institute experience with 290 consecutive patients.

OBJECTIVE: The aim of this study was to determine trends in the incidence of benign lesions in patients undergoing surgery for suspicious renal masses on preoperative computed tomography scan. METHODS: The records of 1065 patients who underwent open consecutive partial nephrectomy (PN) or radical nephrectomy (RN) between January 2001 and December 2008 were reviewed. Patients who underwent PN during the periods 2001-2002, 2003-2004, 2005-2006, and 2007-2008 were assigned to groups 1, 2, 3 and 4, respectively. The frequencies of benign and malignant lesions in these groups were assessed according to size and histology subtypes. RESULTS: The ratio of PN to RN was 12.4%, 18.3%, 24.3% and 37.2% in groups 1, 2, 3 and 4, respectively (P < 0.05). The mean size of resected lesions was 2.6 cm (range 0.8-6.2 cm). Of the 290 cases, histopathology revealed benign findings in 52 (17.9%). Benign pathology was found in three of 18 cases (16.7%) in group 1, seven of 36 cases (19.4%) in group 2, 12 of 63 cases (19.0%) in group 3 and 30 of 173 cases (17.3%) in group 4. There was no significant difference in the frequency of benign histology among groups. CONCLUSION: PN, as opposed to RN, has shown a rising tendency over time. The frequency of benign pathology findings after PN for suspicious renal masses on preoperative computed tomography imaging has not decreased. Proper management should favor nephron-sparing surgery for renal lesions if such lesions can be removed satisfactorily with PN.

The risk factor for urethral recurrence after radical cystectomy in patients with transitional cell carcinoma of the bladder.

PURPOSE: We evaluated the incidence and risk factors for urethral recurrence following radical cystectomy and urinary diversion in transitional cell carcinoma. PATIENTS AND METHODS: A retrospective review was performed of the 412 consecutive patients who underwent radical cystectomy and urinary diversion for transitional cell carcinoma of the bladder between 1986 and 2004. A total of 294 patients were enrolled in this study. We investigated the impact of various clinical and pathological features on urethral recurrence by univariate and multivariate analysis. RESULTS: Urethral recurrence developed in 13 patients (4.4%) and the 5-year urethral recurrence-free probability was 94.9%. On univariate analysis, positive urethral margin, prostatic stromal invasion, and prostatic urethral involvement had a significant influence on urethral recurrence (p < 0.05). The other clinical and pathological features were not significantly associated with urethral recurrence (p > 0.05). A multivariate Cox proportional hazard model revealed that a positive urethral margin (hazards ratio (HR) = 18.33, p < 0.001), prostatic urethral involvement (HR = 7.95, p < 0.001), and prostatic stromal invasion (HR = 5.80, p = 0.018) were independent risk factors for urethral recurrence. CONCLUSION: A positive urethral margin is considered an absolute indication for prophylactic urethrectomy. In addition, more careful patient selection is necessary for orthotopic urinary diversion in patients with prostatic urethral involvement and prostatic stromal invasion.

Clinical significance of lymph node dissection in patients with muscle-invasive upper urinary tract transitional cell carcinoma treated with nephroureterectomy.

We investigated the value of lymph node dissection in patients with cN0 muscle-invasive transitional cell carcinoma of the upper urinary tract (UUT-TCC). Medical records of 152 patients with cN0 muscle-invasive UUT-TCC, who underwent nephroureterectomy between 1986 and 2005, were reviewed. Sixty-three patients (41.4%) underwent lymph node dissection. The median number of lymph nodes harvested was 6 (range, 1 to 35), and from these, lymph node involvement was confirmed in 9 patients (14.3%). Locoregional recurrence (LR) and disease-recurrence (DR) occurred in 29 patients and 63 patients, respectively. Fifty-five patients (36.2%) had died of cancer at the last follow-up. The number of lymph nodes harvested was associated with the reduction of LR (chi(2)(trend)=6.755, P=0.009), but was not associated with DR (chi(2)(trend)=1.558, P=0.212). In the survival analysis, N stage (P=0.0251) and lymph node dissection (P=0.0073) had significant influence on LR, but not on DR or disease-specific survival. However, the number of lymph nodes harvested did not affect LR-free, DR-free, or disease-specific survival. We conclude that lymph node dissection may improve the control of locoregional cancer, as well as staging accuracy, in cN0 muscle-invasive UUT-TCC, but that it does not clearly influence survival.

The prognostic significance of pathologic stage T0 on organ-confined bladder transitional cell carcinoma following radical cystectomy.

INTRODUCTION: We evaluated the prognostic significance of pT0 stage on organ-confined transitional cell carcinoma of the bladder following radical cystectomy. PATIENTS AND METHODS: We retrospectively reviewed the medical records of consecutive patients who underwent radical cystectomy for organ-confined transitional cell carcinoma of the bladder between 1986 and 2004. Patients who were treated with neoadjuvant or adjuvant therapy were excluded. A total of 197 patients were enrolled in this study. We investigated the impact of pathologic T stage on disease-specific survival. RESULTS: Overall disease-specific survival rate was 84.1% after 5 years. Five-year disease-specific survival rates according to pathologic stage were 88.7% in pT0, 92.2% in pTis-1 and 65.4% in pT2 disease. Overall disease-specific survival rate with pTis-1 or pT0 tumors was significantly higher than with pT2 tumors (p = 0.001, pT2 vs. pT0; p < 0.001, pT2 vs. pTis-1), but there was no difference in disease-specific survival between pTis-1 and pT0 tumors (p > 0.05). In the muscle-invasive tumor group, pT0 tumors had a more favorable prognosis than pT2 tumors (p = 0.042), but there was no difference in prognosis between pT0 and pTis-1 tumors. CONCLUSIONS: Pathologic stage T0 cystectomy can be considered a curative therapy in most cases, including pT0cT2 tumors, but there is a substantial risk of tumor recurrence.

CT findings after nephron-sparing surgery of renal tumors.

OBJECTIVE: The purpose of this article is to show the CT findings of the various postoperative changes, surgical complications, and tumor recurrence after nephron-sparing surgery for the treatment of renal tumors. CONCLUSION: Familiarity with the various postoperative changes after nephron-sparing surgery may help radiologists in differentiating these changes from tumor recurrence or surgical complications.

Robot-assisted laparoscopic radical prostatectomy: four cases.

The role of the da Vinci robot is being defined in minimally invasive urologic surgery. Robot-assisted laparoscopic radical prostatectomy (rLRP) has emerged as a feasible treatment option for patients with organ-confined prostate cancer. We performed the first four rLRPs on four prostate cancer patients in the Republic of Korea. This is a report of its techniques and outcomes. In all four cases, the surgery was successfully completed with a mean operative time of 392.5 minutes. The mean estimated blood loss was 312.5mL, and catheterization lasted 14 to 21 days. There were no major intraoperative or postoperative complications. The mean hospital stay was 11 days. The rLRP is a safe and feasible approach. It will become one of the standard options for the management of localized prostate cancer.