Clinical factors predicting the outcome of salvage radiotherapy for patients with biochemical recurrence after radical prostatectomy.

BACKGROUND: It remains unclear which patients with biochemical recurrence after prostatectomy are most suitable for salvage radiotherapy. We evaluated the parameters related to outcomes. METHODS: We retrospectively evaluated patients who underwent salvage therapy for biochemical recurrence after prostatectomy between 2005 and 2019. This study aimed to evaluate biochemical recurrence-free survival (bRFS) after salvage radiotherapy and elucidate the parameters associated with bRFS. The bRFS rate was calculated using the Kaplan-Meier method, and the parameters associated with bRFS were evaluated using Cox regression analysis. RESULTS: This study included 67 patients treated with salvage radiotherapy with a median age of 67 years at salvage radiotherapy. The median follow-up period after salvage radiotherapy was 7.3 years. The 5-year bRFS rate following salvage radiotherapy was 47.1%. Univariate analysis showed that PSA doubling time < 6 months, positive surgical margin, and pathological Gleason score ≥ 8 were significantly associated with shorter bRFS (p < 0.001, p = 0.036, p = 0.047, respectively). Multivariable analysis showed that a PSA doubling time < 6 months and positive surgical margins were significantly associated with shorter bRFS (p = 0.001 and p = 0.018, respectively). No serious adverse events were observed. CONCLUSIONS: In our hospital, approximately half of the patients are under long-term control with salvage radiotherapy. A PSA doubling time of < 6 months and positive surgical margins were suggested to be associated with poor outcomes of salvage radiotherapy.

The efficacy of sequential therapy with docetaxel and cabazitaxel for castration-resistant prostate cancer: A retrospective multi-institutional study in Japan.

OBJECTIVE: This study investigated the efficacy of docetaxel (DOC) and cabazitaxel (CBZ) and examined the factors associated with the prognosis of patients with castration-resistant prostate cancer (CRPC) receiving DOC-CBZ sequential treatment in Japanese real-world data. METHODS: We retrospectively evaluated data for 146 patients who received DOC followed by CBZ. The correlations of prostate specific antigen (PSA) decrease rate and time to progression between DOC and CBZ treatment were examined. Combined progression-free survival (PFS) of DOC-CBZ and overall survival (OS) from the initiation of DOC and the diagnosis of CRPC were evaluated and compared between patients with high and low PSA levels at the start of DOC and CBZ treatment. RESULTS: No correlations of PSA decrease rate and time to progression were observed between DOC and CBZ. The patients for whom DOC was started in higher PSA levels had significantly shorter combined PFS (p = 0.003) and OS from the initiation of DOC (p = 0.002). In patients who started DOC at high PSA levels, those who switched to CBZ at low PSA levels had longer OS than those who switched at high PSA levels (p = 0.048). The OS from CRPC of patients who started DOC at low PSA levels was significantly longer than those that started at high PSA levels (p = 0.030). CONCLUSIONS: For patients for whom DOC was not effective, sequential CBZ might have change to be effective. The PSA levels at the start of DOC and CBZ might be a potential prognostic biomarker.

[Tumor Lysis Syndrome in a Patient with Germ Cell Tumor : A Case Report].

A 36-year-old man presented to our hospital with right scrotal swelling. A computed tomographic scan revealed a mass in the right scrotum, multiple masses in the lung and liver, and enlarged cervical, mediastinal, and retroperitoneal lymph nodes. After right high orchiectomy, he was diagnosed with nonseminomatous germ cell tumor (pT3N3M1b), with poor risk prediction according to the International Germ Cell Consensus classification. We started chemotherapy with bleomycin, etoposide, and cisplatin. Since serum alphafetoprotein (AFP) and human chorionic gonadotropin (HCG) levels did not decrease to normal levels, second-line chemotherapy with paclitaxel, ifosfamide, and cisplatin was administered. Six days after the start of treatment, the patient became unconscious, and his blood pressure decreased. Seven days later, blood tests revealed high uric acid levels, hyperphosphatemia, and increased creatinine. This was diagnosed as tumor lysis syndrome. Following diagnosis, continuous hemodiafiltration was started, and his condition gradually improved.

[A Retrospective Study of Lymph Node Dissection for Renal Cell Carcinoma].

We retrospectively analyzed the effect of lymph node dissection (LND) in patients with renal cell carcinoma (RCC). Of 151 patients who underwent nephrectomy for RCC, 86 underwent LND. No distant metastasis (M0) was present in 71 patients, although distant metastasis (M1) was present in 15. Three (4.2%) and eight (53%) patients in the M0 and M1 groups, respectively, were clinical N-stage positive. Two (2.8%) and three (20%) patients in the M0 and M1 groups, respectively, were pathological N-stage positive. Both pathological N stage-positive patients in the M0 group were pathologically diagnosed with microphthalmia transcription family translocation RCC. The clinical and pathological positive node areas exhibited concordance in all three pathological N stage-positive patients in the M1 group. Chylous leakage occurred in 16 (19%) patients in the LND group (p＜0.05). Extended LND was a statistically significant risk factor for chylous leakage in the multivariate analysis. Only limited cases should undergo LND, owing to the low frequency of positive pathological lymph node metastasis, and high complication rate.

[Diagnostic Accuracy of Transperineal MRI-Ultrasound Fusion Biopsy at the Introduction Period].

Magnetic resonance imaging (MRI) ultrasound fusion biopsy is becoming popular owing to the better detection rate of clinically significant prostate cancer (csPCa). We retrospectively evaluated the accuracy of MRI-targeted biopsy during the period of introduction at a single academic center by comparing findings of its specimen and whole-mount histopathology. Between June 2018 and January 2021, 106 transperineal MRI-ultrasound fusion biopsies using BioJet software were performed. Among the cases, 15 subsequently underwent robotic-assisted laparoscopic radical prostatectomy and were eligible for analysis. This study included all regions of interest (ROIs) with a Prostate Imaging Reporting and Data System v2 category of 3 or greater on pre-biopsy MRI．For each lesion, grade group of MRI-targeted biopsy specimens and prostatectomy specimens were compared. From a total of 25 ROIs identified among 15 males, csPCa was found in 21 (84%) of the concordant locations of prostatectomy specimens. However, MRI-targeted biopsy could diagnose csPCa in only 12 (48%) of them. In the csPCa undetected group, the ROI volume was significantly smaller (median volume 0.23 ml vs 0.40 ml, p＝0.03). We also found that in cases where PCa was not detected through MRI-targeted biopsy, the biopsy sample length was significantly shorter (median length 9 mm vs 17 mm, p＝0.01). Our data suggest that failure of detecting PCa in MRI-targeted biopsy could be due to technical errors at the introduction period of the technique. A sufficient sampling length of 10 mm or more is desirable, especially for small lesions.

Effect of optimal neoadjuvant chemotherapy on oncological outcomes of locally advanced bladder cancer with laparoscopic radical cystectomy: A matched-pair analysis in a multicenter cohort.

OBJECTIVES: To assess the effect of optimal neoadjuvant chemotherapy of at least three cycles of cisplatin-based regimen on oncological outcomes of clinical stage T3 or higher bladder cancer treated with laparoscopic radical cystectomy. METHODS: Laparoscopic radical cystectomies carried out at 10 institutions were included in this retrospective study. The outcomes of patients who received optimal neoadjuvant chemotherapy and those who did not receive neoadjuvant chemotherapy were compared using propensity score matching in clinical stage T3-4 or T2 cohorts, separately. RESULTS: Of the 455 patients screened, matched pairs of 54 patients in the clinical T3-4 cohort and 68 patients in the clinical T2 cohort were finally analyzed. In the cT3-4 cohort, the 5-year overall survival (78% vs 41%; P = 0.014), cancer-specific survival (81% vs 44%; P = 0.008) and recurrence-free survival (71% vs 53%; P = 0.049) were significantly higher in the optimal neoadjuvant chemotherapy group than in the no neoadjuvant chemotherapy group; no significant survival difference was shown between the two groups in the cT2 cohort. In the cT3-4 cohort, the incidence of local recurrence (4% vs 26%; P = 0.025) and abdominal or intrapelvic recurrence, including peritoneal carcinomatosis (7% vs 30%; P = 0.038), was significantly lower in the optimal neoadjuvant chemotherapy group. CONCLUSIONS: Administration of optimal neoadjuvant chemotherapy has a significant survival benefit. It decreases the incidence of local and atypical recurrence patterns in patients with clinical stage T3 or higher locally advanced bladder cancer undergoing laparoscopic radical cystectomy.

[Complete Remission of Metastatic Renal Cell Carcinoma with Invasion of the Duodenum and Pancreas after Treatment with Nivolumab Plus Ipilimumab Followed by Axitinib and Surgery : A Case Report].

A man in his 60s was diagnosed with clear cell carcinoma of the right kidney with multiple lung metastases, tumor thrombus of the inferior vena cava (IVC), and invasion of the duodenum and pancreas. Ipilimumab plus nivolumab was administered as first-line therapy. After 3 treatment courses, computed tomography (CT) demonstrated a slight decrease in the size of the primary tumor and lung metastases. However, the patient became hemodynamically unstable due to persistent duodenal bleeding during treatment despite frequent blood transfusions. Axitinib was then initiated as second-line therapy. The duodenal bleeding ceased 10 days after starting axitinib and his anemia remissed. Subsequent CT showed further decrease in the size of the primary tumor and lung metastases. The patient underwent right nephrectomy after improvement of nutrition. IVC thrombectomy, and pancreaticoduodenectomy. The lung metastases disappeared on postoperative imaging and no additional treatment was provided. Twelve months after surgery, he was in good health and showed no signs of recurrence.

[A Case of Pelvic Unicentric Castleman Disease Treated by Preoperative Transcatheter Arterial Embolization and Tumor Complete Resection with Combined Lower Abdominal and Posterior Approach].

A 22-year-old woman was referred to our hospital for further examination of an incidentally discovered hypervascular pelvic tumor with a maximum diameter of 10 cm. Although Castleman disease was suspected based on the imaging findings and pathologic findings of the needle biopsy, a definitive diagnosis was not made. Preoperative transcatheter arterial embolization was performed to decrease intraoperative bleeding, and tumor resection was performed on the following day. As for posterior approach prior to anterior approach, the patient was placed in a prone position, and the dorsal aspect of tumor was approached through the dissection of gluteal muscles. Then, dilated branches of the internal iliac vein was found on the tumor capsule, which were safely ligated under direct vision with favorable visual field. Then, the patient was placed in a supine position, the tumor was completely resected by anterior approach without transfusion. Histopathological diagnosis was Castleman disease hyaline vascular type. The patient was discharged without complication and has been free from recurrence for 6 months after surgery.

Oncological outcomes and recurrence patterns after laparoscopic radical cystectomy for bladder cancer: A Japanese multicenter cohort.

OBJECTIVE: To investigate oncological outcomes and recurrence patterns after laparoscopic radical cystectomy for bladder cancer in a Japanese multicenter cohort, and to explore the risk factors associated with recurrences due to tumor dissemination. METHOD: Laparoscopic radical cystectomies carried out at 10 institutions were included in this retrospective study. Multivariate analyses were carried out to identify the clinical parameters associated with overall recurrences together with specific recurrence types. Kaplan-Meier curves were created to elucidate time to recurrence and survival. RESULTS: A total of 411 patients were included after the final analysis. Postoperative pathology was T2 or higher in 196 patients (48%), and lymph node metastasis was present in 46 patients (11%). The median follow-up period was 23 months, and the 2-year recurrence-free and cancer-specific survival rates were 71.0% and 84.7%, respectively. The recurrence sites involved distant metastasis in 75 patients (18%), local recurrence in 52 patients (13%) and urinary tract recurrence in eight patients (2%). When local recurrence at the cystectomy bed (28 patients; 7%) and abdominal recurrence including peritoneal carcinomatosis or port site recurrence (17 patients; 4%), which might be caused by tumor dissemination, were combined into a single group, prolonged surgical time was a significant risk factor, in addition to high pathological stage (T3-4 and/or positive lymph nodes), positive surgical margins, and variant histology by both univariate and multivariate analyses. CONCLUSIONS: Our study findings suggest that recurrences after laparoscopic radical cystectomy might be caused by tumor dissemination, and attention should be paid to avoid prolonged surgical time in laparoscopic radical cystectomy.

Perioperative and oncological outcomes of laparoscopic radical cystectomy with intracorporeal versus extracorporeal ileal conduit: A matched-pair comparison in a multicenter cohort in Japan.

OBJECTIVES: To compare the perioperative and oncological outcomes of pure laparoscopic intracorporeal ileal conduit urinary diversion versus extracorporeal ileal conduit urinary diversion after laparoscopic radical cystectomy for bladder cancer in a multicenter cohort in Japan. METHOD: A total of 455 patients who underwent laparoscopic radical cystectomy carried out at 10 institutions were included in this retrospective study. The perioperative data of the intracorporeal ileal conduit urinary diversion and extracorporeal ileal conduit urinary diversion groups were compared using the propensity score matching method. The Kaplan-Meier curves were obtained to elucidate time to ureteroenteric stricture, reoperation, recurrence and survival. RESULTS: In total, 72 matched pairs were evaluated for the final analysis. The median follow-up period was 28 and 23 months in the intracorporeal ileal conduit urinary diversion and extracorporeal ileal conduit urinary diversion groups, respectively. The operative time in the intracorporeal ileal conduit urinary diversion group was approximately 1 h longer than that in the extracorporeal ileal conduit urinary diversion group. The early and late postoperative complication rates were similar in both groups, except for the reduced wound-related complication rates in the intracorporeal ileal conduit urinary diversion group. The median days to regular oral food intake were 4 and 5 days in the intracorporeal ileal conduit urinary diversion and extracorporeal ileal conduit urinary diversion groups, respectively (P = 0.014). No significant difference was noted in the occurrence of ureteroenteric strictures and reoperation rate. Furthermore, recurrence-free, cancer-specific, and overall survival rates and recurrence patterns did not significantly differ. CONCLUSIONS: Laparoscopic intracorporeal ileal conduit urinary diversion is a safe, feasible and reproducible procedure with similar postoperative complication rates, ureteroenteric stricture rate and oncological outcomes when compared with extracorporeal ileal conduit urinary diversion, but faster postoperative bowel recovery and decreased wound-related complication rates.

Laparoscopic radical cystectomy in octogenarians: analysis of a Japanese multicenter cohort.

BACKGROUNDS: This study aimed to describe the morbidity and mortality in older patients undergoing laparoscopic radical cystectomy (LRC) and compare the outcomes of LRC between octogenarians and younger patients (< 80 years) in a Japanese multicenter cohort. METHODS: We identified 433 patients (80 octogenarians) who underwent LRC in a retrospective multicenter database from 10 institutions. The perioperative outcomes and the 90-day and late (> 90-day) complications according to the Clavien-Dindo classification were compared between the octogenarians and younger patients. Recurrence-free survival (RFS), overall survival (OS), and cancer-specific survival (CSS) were measured by the Kaplan-Meier method. RESULTS: Compared with the younger group, the octogenarian group included a significantly higher proportion of women, patients with a lower body mass index, patients with a lower preoperative albumin level, and patients with a history of abdominal surgery. The 90-day rates of all complications and major complications (grades III-V) were 50.0% and 20.0% among octogenarians and 54.7% and 16.4% among younger patients. The 90-day mortality rate among octogenarians was 3.8%. The 2-year RFS, CSS, and OS rates for octogenarians stratified by pathological stage was 95.2, 100, and 100% for ≤ pT1; 50.7, 76.6, and 56.1% for pT2; 33.6, 82.5, and 72.6% for ≥ pT3; and 23.1, 42.2, and 37.5% for pN + or distant metastasis, respectively. There was significant difference between octogenarians and younger patients only in 2-year OS for pT2 (56.1% vs 87.7%, p = 0.03). CONCLUSIONS: This study revealed that LRC can be performed for selected octogenarians with a complication rate similar to that of younger patients. Appropriate risk evaluation and modification of surgical procedures are necessary for octogenarians.

Complications and reoperations after laparoscopic radical cystectomy in a Japanese multicenter cohort.

OBJECTIVES: To describe the complications and their surgical management after laparoscopic radical cystectomy in a Japanese multicenter cohort. METHODS: The participants were drawn from a retrospective multicenter study at 10 institutions. We identified 436 patients who underwent laparoscopic radical cystectomy with no robot assistance. Early and late complications were graded according to their Clavien-Dindo classification. The records of all patients who underwent surgical interventions for laparoscopic radical cystectomy-specific complications were also reviewed. Kaplan-Meier curves were used to describe the time to surgical intervention. RESULTS: The 90-day rates for overall complications, high-grade complications (Clavien-Dindo classification III-V) and mortality were 53%, 17% and 1.4%, respectively. Gastrointestinal (25%), infectious (22%) and abdominal wall-related (9%) complications were the most common. The late complication rate was 18%, and a total of 81 patients (19%) underwent surgical intervention during the median follow-up period of 22 months. The reoperation rate was 25% at 5 years. Gastrointestinal complications in the early postoperative period and abdominal wall-related complications in the late postoperative period were the main reasons for reoperation. Seven (7%) out of 100 female patients underwent emergent surgical reoperation for transvaginal bowel evisceration as a result of vaginal dehiscence. CONCLUSIONS: Early and late postoperative complications and surgical reoperations are notable after laparoscopic radical cystectomy. Abdominal wall-related complications including vaginal dehiscence are common, and they represent the main indication for reoperation during long-term follow up.

[Post-Operative Urethral Stricture after Holmium Laser Enucleation of the Prostate].

Holmium laser enucleation of the prostate (HoLEP) is a safe and effective surgical procedure for patients suffering from comparatively larger benign prostatic hyperplasia. However, the rate of postoperative urethral stricture (POUS) is relatively high, which can render further invasive intervention. Here we assessed the POUS rate, riskfactors and outcomes in 206 patients with benign prostatic hyperplasia who underwent HoLEP at our hospital between January 2006 and December 2015. POUS was observed in 24 patients (11.7%). The rate of intraoperative urethral stricture was significantly higher in the patients with POUS (8 out of 24 patients, 33.3%) than in those without POUS (12 out of 186 patients, 6.6%). The odds ratio was 7.08, 95% and combination index (CI) was 2.53-19.9, p<0.001). The relative riskfor POUS based on intraoperative urethral stricture was 4.65 (95% CI : 2.28-9.48). The most common POUS site was external urethral orifice (12 out of 24 cases). The POUS onset was significantly earlier in patients with external urethral orifice than the other sites (p=0.0389). The site of postoperative stricture concurred with that of intraoperative stricture at a high rate (7 out of 8 patients). Significant differences were observed between patients with and without POUS within one month in international prostate symptom score, quality of life score and in Qmax after the operation, while they were improved by simple interventions such as bougie. In conclusion, we should consider the possibility of POUS when the patient had an intraoperative stricture in HoLEP.

[A Case of Advanced Right Renal Pelvic Cancer with Left Supraclavicular Lymph Node Metastasis that Attained Long-Term Survival by Multidisciplinary Treatments].

A man in his 70s was referred to our hospital for further examination of a positive occult blood finding. Imaging studies showed that the patient had right renal pelvic cancer with interaortocaval, multiple paracaval and left supraclavicular lymph node metastases (cT3N2Ml). Induction chemotherapy was performed with 5 cycles of MEC (methotrexate/epirubicin/cisplatin) followed by 2 cycles of GT (gemcitabine/paclitaxel). After the combined chemotherapies, the residual lesions were the primary tumor in the right renal pelvis and the left supraclavicular lymph node. Right total nephroureterectomy combined with lymph node dissection of paraaortic, paracaval, and interaortocaval area and left cervical area were performed. Histopathologically the postoperative T stage of the primary tumor was determined as ypT3. As for lymph nodes dissected, an interaortocaval lymph node alone, but not the other nodes, contained viable cancer cells. Adjuvant chemotherapy was performed with 7 courses of GT therapy. The patient had intravesical recurrence once and received transurethral resection of bladder tumor followed by intravesical instillations of Bacillus Calmette-Guerin (BCG). Finally, the patient has been free from recurrence for 10 years after the final treatment.

[Clinical Effect of Nivolumab on Advanced Renal Cell Carcinoma with Peritoneal Metastasis].

Peritoneal dissemination or metastasis is a relatively rare presentation of renal cell carcinoma. We report four cases of advanced renal cell carcinoma with peritoneal metastases treated with nivolumab. Three cases showed an objective response in the metastatic lesions including peritoneal sites. After nivolumab administration, the computed tomography scan showed a transient enlargement of peritoneal lesions in two cases, which could be considered as pseudoprogression. Temporal changes of neutrophil-tolymphocyte ratio, C-reactive protein, and eosinophil ratio during the clinical course reflected the treatment effect of nivolumab in these patients, indicating that these could be potential biomarkers of the response. To our knowledge, this is the first case series showing therapeutic activity of nivolumab against peritoneal metastases in patients with renal cell carcinoma.

[Kidney Auto-Transplantation for Intraoperative Right Renal Artery Injury in a Single Kidney Patient : A Case Report].

A man in his 70's who had undergone left radical nephrectomy for kidney cancer had the right renal artery ablated unexpectedly during pancreatoduodenectomy for a huge duodenal tumor. For this intraoperative emergency, an autologous kidney transplantation was performed with the right kidney being removed, perfused, and transplanted into the right iliac fossa. Warm ischemic time was over 2 hours. The patient developed postoperative hemorrhagic infarction of a renal artery branch, which was successfully treated with intravascular intervention. The patient was weaned off hemodialysis and was discharged in 16 weeks postoperatively.

[A Case of Late Onset Nivolumab-Induced Interstitial Nephritis in a Patient with Metastatic Renal Cell Carcinoma].

A 43-year-old man underwent nephrectomy for right renal cell carcinoma (cT3aN0M1 (PUL), clear cell carcinoma). Thereafter, he was treated with sunitinib for lung metastases as the first-line therapy for three months. Because lung metastases progressed and new bone metastases appeared, nivolumab was started for the second-line treatment. Although the cancer progression was suppressed by multidisciplinary treatment combined with systemic immunotherapy and local radiation therapy, he developed severe acute kidney injury with cortical swelling after eighteen months of nivolumab treatment. A diagnosis of acute interstitial nephritis induced by nivolumab was made based on biopsy findings. Treatment with prednisolone (1.0 mg/kg daily) led to a rapid improvement in renal function. We must consider the possibility of immunerelated adverse events, especially nivolumab-induced acute kidney injury, even after long-term treatment.

[The Safety of Laparoscopic Radical Cystectomy during Initial Phases in a Japanese Multicenter Cohort].

We evaluated the safety of laparoscopic radical cystectomy (LRC) during initial phases and its learning curve in a Japanese multicenter cohort by studying 436 patients who underwent LRC with no robot assistance at 10 institutions in Japan. We divided the patients into three groups according to cumulative surgical volume at each institution (first 10 cases, 11-30 cases, after 31 cases in each institution), and compared perioperative and pathologic variables among the three groups. The first, second, and third groups included 100, 166, 170 patients, respectively. The preoperative variables were similar in the three groups except for the rate of neoadjuvant chemotherapy. The methods of LRC procedure, such as urinary diversion, the extent of lymph node dissection, and concomitant urethrectomy or nephroureterectomy, were similar in the three groups. Mean operative time was 629, 562 and 531 minutes, respectively, and mean blood loss was 755, 650 and 435 ml, respectively. Both values decreased over time with the institution's experience. There was no significant difference among the three groups in the rate of positive surgical margin, the number of retrieved lymph nodes, and the rate of intra- and postoperative complications. LRC was safely performed during initial phases with an acceptable complication rate and without compromising oncological results, although operative time was longer and blood loss increased.

Impact of a robotic surgical system on treatment choice for men with clinically organ-confined prostate cancer.

BACKGROUND: Introducing a new surgical technology may affect behaviors and attitudes of patients and surgeons about clinical practice. Robot-assisted laparoscopic radical prostatectomy (RALP) was approved in 2012 in Japan. We investigated whether the introduction of this system affected the treatment of organ-confined prostate cancer (PCa) and the use of radical prostatectomy (RP). METHODS: We conducted a retrospective multicenter study on 718 patients with clinically determined organ-confined PCa treated at one of three Japanese academic institutions in 2011 (n = 338) or 2013 (n = 380). Two patient groups formed according to the treatment year were compared regarding the clinical characteristics of PCa, whether referred or screened at our hospital, comorbidities and surgical risk, and choice of primary treatment. RESULTS: Distribution of PCa risk was not changed by the introduction of RALP. Use of RP increased by 70% (from 127 to 221 cases, p < 0.0001), whereas the number of those undergoing radiotherapy or androgen deprivation therapy decreased irrespective of the disease risk of PCa. Increased use of RP (from 34 to 100 cases) for intermediate- or high-risk PCa patients with mild perioperative risk (American Society of Anesthesiologists score 2) accounted for 70% of the total RP increase, whereas the number of low- or very low-risk PCa patients with high comorbidity scores (Charlson Index ≥ 4) increased from 8 to 25 cases, accounting for 18%. Use of expectant management (active surveillance, watchful waiting) in very low-risk PCa patients was 15% in 2011 and 12% in 2013 (p = 0.791). CONCLUSIONS: Introduction of a robotic surgical system had little effect on the risk distribution of PCa. Use of RP increased, apparently due to increased indications in patients who are candidates for RP but have mild perioperative risk. Although small, there was an increase in the number of RPs performed on patients with severe comorbidities but with low-risk or very low-risk PCa.

[Initial Clinical Experience of Nivolumab for Metastatic Renal Cell Carcinoma].

Nivolumab was approved as a new agent for advanced renal cell carcinoma (RCC) in Japan on September 2016. Nivolumab is an immune checkpoint inhibitor that activates the cytotoxic immune response and has exerted antitumor effects in a mechanism different from other available molecular targeted agents. Therefore, its response pattern, efficacy and adverse events are different from those of the molecular targeted agents for RCC. Here, we report our initial clinical experience with nivolumab. From December 2016 to September 2017, we applied nivolumab to 7 patients with metastatic RCC. The most common metastatic site was the lungs, followed by lymph nodes, bones and brain. According to the immune-related response criteria, the efficacy was stable disease in 2 patients and progressive disease in 5 patients. In 5 cases with multiple metastases, responses differed with the site of metastasis. The response was best in lung metastasis and worst in brain metastasis. Six cases had minor adverse events. In two cases, we discontinued administration of nivolumab temporarily. The patients recovered completely and we considered nivolumab effective and safe for treatment of metastatic RCC.