Current status and future perspectives on robot-assisted kidney autotransplantation: A literature review.

This review presents the latest insights on robot-assisted kidney autotransplantation (RAKAT). RAKAT is a minimally invasive surgical procedure and represents a promising alternative to conventional laparoscopic nephrectomy followed by open kidney transplantation for the treatment of various complex urological and vascular conditions. RAKAT can be performed either extracorporeally or intracorporeally. Additionally, a single-port approach can be performed through one small incision without the need to reposition the patient. Of 86 patients undergoing RAKAT, 8 (9.3%) developed postoperative > Grade 2 Clavien-Dindo (CD) complications. Although the feasibility of RAKAT was established in 2014, the long-term efficacy and safety along with outcomes of this surgical approach are still being evaluated, and additional studies are needed. With improvements in the technology of RAKAT and as surgeons gain more experience, RAKAT should become increasingly used and further refined, thereby leading to improved surgical outcomes and improved patients' quality of life.

Safety of early rehabilitation in patients with aneurysmal subarachnoid hemorrhage: A retrospective cohort study.

OBJECTIVE: To investigate the safety and efficacy of early rehabilitation in patients with aneurysmal subarachnoid hemorrhage (aSAH) patients. METHODS: One hundred eleven patients with aSAH admitted between April 2015 and March 2019, were retrospectively evaluated. The early rehabilitation program was introduced in April 2017 to actively promote mobilization and walking training for aSAH patients. Therefore, patients were divided into two groups (The conventional group (n = 55) and the early rehabilitation group (n == 56). Clinical characteristics, mobilization progression, and treatment variables were analyzed. Complications (rebleeding, symptomatic cerebral vasospasm, hydrocephalus, disuse complications,) and a modified Rankin Scale (mRS) at 90 days were compared in two groups. Factors associated with favorable outcomes (mRS≤2) at 90 days were also assessed. RESULTS: The early rehabilitation group had a significantly shorter span to first walking (9 vs. 5 days; P = 0.007). The prevalence of complications was not significantly increased in the early rehabilitation group. Approximately 40% of patients in both groups had pneumonia and urinary tract infections but significantly reduced antibiotic-administration days (13 vs. 6 days; P < 0.001). mRS at 90 days also showed significant improvement in the early rehabilitation group (3 vs. 2; P=0.01). Multivariate logistic regression analysis of favorable outcomes associated that the administration of the early rehabilitation program has a significant independent factor (odds ratio, 3.03; 95% confidence interval, 1.1-8.37). CONCLUSIONS: Early rehabilitation for patients with aSAH can be feasible without increasing complication occurrences. The early rehabilitation program with active mobilization and walking training reduced antibiotic use and was associated with improved independence.

Long-term ureteroscopic management of upper tract urothelial carcinoma: 28-year single-centre experience.

BACKGROUND: Long-term survival outcomes of patients who undergo endoscopic management of non-invasive upper tract urothelial carcinoma remain uncertain. The longest mean follow-up period in previous studies was 6.1 years. This study reports the long-term outcomes of patients with upper tract urothelial carcinoma who underwent ureteroscopic ablation at a single institution over a 28-year period. METHODS: We identified all patients who underwent ureteroscopic management of upper tract urothelial carcinoma as their primary treatment at our institution between January 1991 and April 2011. Survival outcomes, including overall survival, cancer-specific survival, upper-tract recurrence-free survival and renal unit survival, were estimated using Kaplan-Meier methodology. RESULTS: A total of 15 patients underwent endoscopic management, with a mean age at diagnosis of 66 years. All patients underwent ureteroscopy, and biopsy-confirmed pathology was obtained. Median (range; mean) follow-up was 11.7 (2.3-20.9, 11.9) years. Upper tract recurrence occurred in 87% (n = 13) of patients. Twenty percent (n = 3) of patients proceeded to nephroureterectomy. The estimated cancer-specific survival rate was 93% at 5, 10, 15 and 20 years. Estimated overall survival rates were 86, 80, 54 and 20% at 5, 10, 15 and 20 years. Only one patient experienced cancer-specific mortality. The estimated mean and median overall survival times were 14.5 and 16.6 years, respectively. The estimated mean cancer-specific survival time was not reached. CONCLUSIONS: Although upper tract recurrence is common, endoscopic management of non-invasive upper tract urothelial carcinoma provides a 90% cancer-specific survival rate at 20 years in selected patients.

Photodynamic diagnostic ureteroscopy using the VISERA ELITE video system for diagnosis of upper-urinary tract urothelial carcinoma: a prospective cohort pilot study.

BACKGROUND: The advantages of photodynamic diagnostic technology using 5-aminolevulinic acid (ALA-PDD) have been established. The aim of this prospective cohort study was to evaluate the usefulness of ALA-PDD to diagnose upper tract urothelial carcinoma (UT-UC) using the Olympus VISERA ELITE video system. METHODS: We carried out a prospective, interventional, non-randomized, non-contrast and open label cohort pilot study that involved patients who underwent ureterorenoscopy (URS) to detect UT-UC. 5-aminolevulinic acid hydrochloride was orally administered before URS. The observational results and pathological diagnosis with ALA-PDD and traditional white light methods were compared, and the proportion of positive subjects and specimens were calculated. RESULTS: A total of 20 patients were enrolled and one patient who had multiple bladder tumors did not undergo URS. Fifteen of 19 patients were pathologically diagnosed with UT-UC and of these 11 (73.3%) were ALA-PDD positive. Fourteen of 19 patients were ALA-PDD positive and of these 11 were pathologically diagnosed with UC. For the 92 biopsy specimens that were malignant or benign, the sensitivity for both traditional white light observation and ALA-PDD was the same at 62.5%, whereas the specificities were 73.1% and 67.3%, respectively. Of the 38 specimens that were randomly biopsied without any abnormality under examination by both white light and ALA-PDD, 11 specimens (28.9%) from 5 patients were diagnosed with high grade UC. In contrast, four specimens from 4 patients, which were negative in traditional white light observation but positive in ALA-PDD, were diagnosed with carcinoma in situ (CIS). CONCLUSIONS: Our results suggest that ALA-PDD using VISERA ELITE is not sufficiently applicable for UT-UC. Nevertheless, it might be better particularly for CIS than white light and superior results would be obtained using VISERA ELITE II video system. TRIAL REGISTRATION: The present clinical study was approved by the Okayama University Institutional Review Board prior to study initiation (Application no.: RIN 1803-002) and was registered with the UMIN Clinical Trials Registry (UMIN-CTR), Japan (Accession no.: UMIN000031205).

Successful deceased donor kidney transplantation to a recipient with a history of COVID-19 treatment.

CASE PRESENTATION: A 49-year-old Asian male, who had undergone hemodialysis for >16 years, complained of a fever, dysgeusia and dysosmia, and was diagnosed with COVID-19 pneumonia based on severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (SARS-CoV-2 PCR) and computed tomography (CT). Treatment was started with oral favipiravir and ciclesonide inhalation. On the 10th day of treatment, the patient had a persistent high fever and a chest CT showed exacerbation of pneumonia, so dexamethasone was intravenously started. He was discharged after confirming two consecutive negative SARS-CoV-2 PCR tests. Three months after COVID-19 treatment, a SARS-CoV-2 PCR test was negative and he underwent a deceased donor kidney transplantation. Basiliximab induction with triple drug immunosuppression consisting of extended-release tacrolimus, mycophenolate mofetil and prednisolone, which is our regular immunosuppression protocol, was used. He was discharged on postoperative day 18 without the need for postoperative hemodialysis or any complications. The serum creatinine level was 1.72 mg/dL 95 days postoperatively and he had a favorable clinical course that was similar to deceased donor kidney recipients without a history of SARS-CoV-2 infection. CONCLUSION: We report the first case of a kidney transplantation after COVID-19 treatment in Japan and the fourth case globally. We would like to provide information about our successful case due to the anticipated increase in similar candidates in the near future.

Comparison of intracorporeal versus extracorporeal urinary diversion after robot-assisted radical cystectomy at a medium-sized facility.

BACKGROUND: The aim of this study is to compare the perioperative outcomes and learning curves between intracorporeal and extracorporeal urinary diversion at our medium-sized institution. METHODS: Between January 2018 and September 2020, a single surgeon at our institution performed 46 consecutive robot-assisted radical cystectomies with ileal conduit. We compared the perioperative outcomes between patients who underwent intracorporeal versus extracorporeal urinary diversion. We also investigated learning curves for the first and last 10 patients in each group. RESULTS: The extracorporeal group had shorter overall operative time (P = 0.003) and urinary diversion time (P < 0.0001) than the intracorporeal group. The intracorporeal group had shorter length of hospital stay (P = 0.02). There was no difference in complication and readmission rates. The extracorporeal group demonstrated no difference between the first and last 10 patients for overall operative time or time for cystectomy, lymph node dissection, or urinary diversion. However, the intracorporeal group had shorter urinary diversion time for the last 10 patients compared with the first 10 patients. The first 10 patients in the extracorporeal group had shorter overall operative time than the first 10 in the intracorporeal group, but there was no difference for the last 10 patients. CONCLUSIONS: Intracorporeal urinary diversion requires longer overall operative time than extracorporeal diversion for the first 10 patients, due to longer urinary diversion time. However, there is no difference in overall operative time for the last 10 patients. The benefit of intracorporeal over extracorporeal urinary diversion was not confirmed at our medium-sized institution.

Clinical Efficacy and Safety of Sitafloxacin 200 mg Once Daily for Refractory Genitourinary Tract Infections.

The aim of this ongoing trial is to evaluate the clinical efficacy and safety of sitafloxacin (STFX) 200 mg once daily (QD) for 7 days in patients with refractory genitourinary tract infections, which include recurrent or complicated cystitis, complicated pyelonephritis, bacterial prostatitis, and epididymitis. The primary endpoint is the microbiological efficacy at 5-9 days after the last administration of STFX. Recruitment began in February 2021, and the target total sample size is 92 participants.

A Case of Metastatic Fumarate Hydratase-Deficient-like Renal Cell Carcinoma Successfully Managed by Ipilimumab plus Nivolumab.

We report a 62-year-old male with metastatic fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) without fumarate hydratase (FH) mutation (FH-deficient-like RCC). The International Metastatic RCC Database Consortium risk score was intermediate, and immunotherapy with nivolumab and ipilimumab (Ipi/ Nivo) was initiated. Four cycles of Ipi/Nivo and 5 cycles of nivolumab resulted in a complete response of the metastases. Hypophysitis occurred as an immune-related adverse event after four cycles of Ipi/Nivo. The prognosis of patients with FH-deficient RCC is generally poor. Few reports of FH-deficient RCC successfully treated with Ipi/Nivo have been published. Ipi/Nivo can be effective for treating FH-deficient RCC.

Presence of decoy cells for 6 months on urine cytology efficiently predicts BK virus nephropathy in renal transplant recipients.

OBJECTIVES: To investigate the association between duration of consecutive presence of decoy cells on urine cytology and BK virus nephropathy after kidney transplantation. METHODS: In total, 121 kidney transplant recipients were retrospectively evaluated. The best duration of consecutive presence of decoy cells that could be used to predict BK virus nephropathy was analyzed using the area under the curve for each duration, and recipients were divided into two groups based on the best predictive performance. The effectiveness of SV40 immunostaining on urinary cytology was also analyzed. RESULTS: In total, 2534 urine specimens as well as SV40 immunostaining in 2241 urine specimens were analyzed. Six consecutive months of decoy cell positivity had the best predictive performance for BK virus nephropathy (area under the curve = 0.832). The incidence of BK virus nephropathy in recipients with positive decoy cells for 6 months or more consecutive months (5/44) was significantly higher than in those who had positive decoy cells for less than 6 months (0/77; P = 0.005). Decoy cell positivity had a sensitivity, specificity, positive predictive value, and negative predictive value for BK virus nephropathy of 100%, 66%, 11%, and 100% respectively. SV40 immunostaining provided slightly better specificity (68%) and positive predictive value (12%). CONCLUSIONS: The detection of decoy cells at 6 months or more on urine cytology had high predictive value for BK virus nephropathy in kidney transplant recipients. SV40 immunostaining on urine cytology added minimal diagnostic accuracy.

Combined Laparoscopic and CT Monitoring of the Ice-Ball Margin during Cryoablation for Renal Cell Carcinoma Associated with von Hippel-Lindau Disease: First Case.

We report a 47-year-old Japanese female with 10 previous treatments for multiple bilateral renal cell carcinoma (RCC) associated with von Hippel-Lindau disease. The 14-mm right lower pole renal tumor was in contact with the right ureter. Laparoscopic cryoablation was performed to protect the ureter wrapped with gauze. Computed tomography (CT) monitoring was used to confirm the precise ≥ 6 mm ice-ball margin. There was no local progression at 6-months post-surgery. The serum creatinine has been stable. This is apparently the first report of combined laparoscopic and CT monitoring of an ice-ball formation and its margin during cryoablation for RCC.

Robotic Renal Autotransplantation: A Feasibility Study in a Porcine Model.

We investigated the feasibility of robotic renal autotransplantation (RAT) in a porcine model to reduce invasiveness of RAT. Five pigs underwent robotic RAT using the da Vinci® robotic system. A robotic left nephrectomy was performed in all cases. Robotic RAT was performed on the left side in all but one case. Four ports were used. In 3 cases, the kidney was taken out through the GelPort® and irrigated on ice with Ringer's solution. In 2 cases, a complete intracorporeal robotic RAT was performed. An end-to-side anastomosis was performed between the renal vein and the external iliac vein and between the renal artery and the external iliac artery. Ureteroneocystostomy was also performed in 2 cases. All cases were performed robotically without open conversion. The median (IQR) console time was 3.1 (0.7) h, and the operative time was 3.8 (1.1) h. The estimated blood loss was 30 (0) ml. The warm ischemia time was 4.0 (0.2) min, and the cold ischemia time was 97 (17) min. Intracorporeal transarterial hypothermic renal perfusion was feasible in the 2 complete intracorporeal robotic RAT cases by using a perfusion catheter through a laparoscopic port. Robotic RAT has the potential to be a new minimally invasive substitute for conventional open surgery.

Low-dose rituximab induction therapy is effective in immunological high-risk renal transplantation without increasing cytomegalovirus infection.

OBJECTIVES: To analyze the effect and impact of low-dose rituximab induction therapy on cytomegalovirus infection in living-donor renal transplantation. METHODS: A total of 92 recipients undergoing living-donor renal transplantation at Okayama University Hospital from May 2009 to August 2018 were evaluated retrospectively. Indications for preoperative rituximab (200 mg/body) were the following: (i) ABO major mismatch; (ii) ABO minor mismatch; (iii) donor-specific anti-human leukocyte antigen antibody-positive; and (iv) focal segmental glomerulosclerosis. We excluded four recipients who were followed <3 months, five who received >200 mg/body rituximab and seven who received prophylactic therapy for cytomegalovirus. RESULTS: There were 59 patients in the rituximab group and 17 in the non-rituximab group. Groups differed significantly in age (median age 53 vs 37 years, respectively; P = 0.04), but not in sex (male 64% vs 65%, P = 1.00), focal segmental glomerulosclerosis (3% vs 0%, P = 1.00) or percentage of cytomegalovirus-seronegative recipients of renal allografts from cytomegalovirus-seropositive donors (12% vs 18%, P = 0.68). The estimated glomerular filtration rate did not differ significantly between groups until 24 months after transplantation. Cytomegalovirus clinical symptoms (10% vs 24%, P = 0.22), including fever ≥38°C (5% vs 12%, P = 0.31) and gastrointestinal symptoms (5% vs 12%, P = 0.31), and the 5-year survival rates of death-censored graft loss (90% vs 83%, P = 0.43) did not differ significantly between groups. CONCLUSIONS: Low-dose rituximab induction therapy is effective in immunological high-risk recipients without increasing cytomegalovirus infection in the absence of valganciclovir prophylaxis.

Use of single-dose perioperative antimicrobial therapy is acceptable in recipients of living-donor renal transplants in the rituximab era.

OBJECTIVE: The aim of this study was to evaluate the efficacy of single-dose perioperative antimicrobial therapy as infection prophylaxis in recipients of living-donor renal transplants in the rituximab era. PATIENTS AND METHODS: Between 2009 and 2017, 84 recipients underwent living-donor renal transplantation (LDRT) at Okayama University Hospital; 3 with vascular/urinary complications requiring additional surgery were excluded from this analysis. Data including recipient characteristics, antimicrobial prophylaxis and administration of rituximab were retrospectively examined for an association with perioperative infections. Prophylactic antimicrobial agents, selected according to the Results of preoperative urine cultures, were administered just before incision. Perioperative infections, which consisted of surgical site infections, remote infections, and urinary tract infections, were defined as a positive culture indicating required administration of additional antimicrobial agents. RESULTS: Among the 81 recipients, prophylactic cefazolin, ampicillin/sulbactam, and others were administered to 66 (82%), 13 (16%), and 2 (3%) recipients, respectively. Twenty-one (26%) received single-dose antimicrobial prophylaxis, while 60 (74%) received multiple doses up to 7 days. Rituximab was used in 59 (72.8%) recipients. The incidence of urinary tract infection, surgical site infection and remote infection was 13 (16%), 1 (1%), and 0, respectively. Univariate analysis could not demonstrate any significant risk factors for postoperative urinary tract infections, including a single dose vs multiple doses of antimicrobial therapy (P = 0.069) and administration of rituximab (P = 0.717). CONCLUSIONS: Our data suggest that the use of single-dose perioperative antimicrobial therapy is acceptable for prophylaxis of infections in patients undergoing LDRT, even in the rituximab era.

Contrast-enhanced Computed Tomography-Guided Percutaneous Cryoablation of Renal Cell Carcinoma in a Renal Allograft: First Case in Asia.

Nephron-sparing treatment should be offered whenever possible to avoid dialysis in allograph cases. Cryoablation is a new treatment option for treating small-sized renal cell cancer (RCCs). We report a case of RCC arising in a kidney allograft treated by cryoablation. To our knowledge, this is the first case in Asia of RCC in a renal allograft treated using cryoablation. Contrast-enhanced CT-guided percutaneous renal needle biopsy and cryoablation were used to identify the RCC, which could not be identified by other techniques. The postoperative course was uneventful. Contrast-enhanced CT also showed no recurrence or metastases at the 6-month follow-up.

Ureterolithotripsy for a Ureteral Calculus at the Ureteroureterostomy of a Renal-transplant Recipient.

We describe a 40-year-old living-donor renal-transplant recipient who underwent successful ureterolithotripsy. He had been on hemodialysis for >15 years pre-transplant and underwent ureteroureterostomy along with the surgery. One year post-transplant, ultrasound examination demonstrated hydronephrosis, and CT showed a 6-mm ureteral calculus at the ureteroureterostomy site. No pain and no elevated serum creatinine were present. As the ureter was easily accessed, we performed a ureterolithotripsy, which would confirm whether a suture caused the calculus. Despite ureteral tortuosity, laser stone fragmentation succeeded. The calculus was completely removed with an antegrade guidewire. Mild postoperative ureteral stenosis resolved with a temporary ureteral stent without balloon dilation. Ureterolithotripsy is effective even in renal transplant recipients with ureteroureterostomy.

Robotic Renal Autotransplantation: First Case Outside of North America.

A 38-year-old woman with a 2.7-cm left ureteral stenosis requiring chronic ureteral stent exchange elected to undergo robotic renal autotransplantation. Left ureteropelvic junction obstruction (UPJO) was also suspected. Robotic donor nephrectomy contributed to the fine dissection for desmoplastic changes. The kidney was removed through a Gelport and examined on ice. UPJO was not seen. An end-to-side robotic anastomosis was created between the renal and external iliac vessels. The console time was 507 min, and the warm ischemia time was 4 min 5 sec. She became stent-free. Robotic renal autotransplantation is a new, minimally invasive approach to renal preservation.

Identification of Phosphoinositide-Binding Protein PATELLIN2 as a Substrate of Arabidopsis MPK4 MAP Kinase during Septum Formation in Cytokinesis.

The phosphorylation of proteins by protein kinases controls many cellular and physiological processes, which include intracellular signal transduction. However, the underlying molecular mechanisms of such controls and numerous substrates of protein kinases remain to be characterized. The mitogen-activated protein kinase (MAPK) cascade is of particular importance in a variety of extracellular and intracellular signaling processes. In plant cells, the progression of cytokinesis is an excellent example of an intracellular phenomenon that requires the MAPK cascade. However, the way in which MAPKs control downstream processes during cytokinesis in plant cells remains to be fully determined. We show here that comparisons, by two-dimensional difference gel electrophoresis, of phosphorylated proteins from wild-type Arabidopsis thaliana and mutant plants defective in a MAPK cascade allow identification of substrates of a specific MAPK. Using this method, we identified the PATELLIN2 (PATL2) protein, which has a SEC14 domain, as a substrate of MPK4 MAP kinase. PATL2 was concentrated at the cell division plane, as is MPK4, and had binding affinity for phosphoinositides. This binding affinity was altered after phosphorylation of PATL2 by MPK4, suggesting a role for the MAPK cascade in the formation of cell plates via regeneration of membranes during cytokinesis.

Effect of Antacids on the Survival of Patients With Metastatic Urothelial Carcinoma Treated With Pembrolizumab.

INTRODUCTION: Concomitant medications can affect the efficacy of immune checkpoint inhibitors. The association between histamine-2 receptor antagonists (H2RAs), major antacids similar to proton pump inhibitors (PPIs), and the efficacy of pembrolizumab for metastatic urothelial carcinoma (mUC) treatment has been poorly evaluated. We evaluated the impact of PPIs and H2RAs on oncological outcomes in mUC patients treated with pembrolizumab. PATIENTS AND METHODS: This retrospective multicenter study included patients with mUC treated with pembrolizumab. Patients prescribed PPIs or H2RAs within 30 days before and after the initial administration were extracted. The overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), and objective response rates (ORR) were assessed. Kaplan-Meier survival curve analysis and multivariable Cox proportional hazard models were employed to assess the association between PPIs or H2RAs and survival outcomes. RESULTS: Overall, 404 patients were eligible for this study; 121 patients (29.9%) used PPIs, and 34 (8.4%) used H2RAs. Kaplan-Meier analysis showed significantly worse OS, CSS, and PFS in patients using PPIs compared to no PPIs (P = .010, .018, and .012, respectively). In multivariable analyses, the use of PPIs was a significant prognostic factor for worse OS (HR = 1.42, 95% CI 1.08-1.87, P = .011), CSS (HR = 1.45, 95% CI 1.09-1.93, P = .011), and PFS (HR = 1.35, 95% CI 1.05-1.73, P = .020). PPIs were not associated with ORRs. The use of H2RAs was not associated with survival or ORRs. CONCLUSION: PPIs were significantly associated with worse survival of patients with mUC treated with pembrolizumab, and H2RAs could be an alternative during administration. Both the oncological and gastrointestinal implications should be carefully considered when switching these antacids.

Trans men can achieve adequate muscular development through low-dose testosterone therapy: A long-term study on body composition changes.

BACKGROUND: Transgender individuals undergo the gender-affirming hormone therapy (GAHT) to achieve physical changes consistent with their gender identity. Few studies are available on the long-term safety and efficacy of GAHT. OBJECTIVES: To investigate the long-term physical effects and the safety of the testosterone therapy for trans men and to assess the impact of differential hormone dose. MATERIALS AND METHODS: Trans men who initiated GAHT between May 2000 and December 2021 were included in this retrospective analysis. Physical findings (body mass index, body fat percentage (BFP), lean body mass (LBM), and grip strength), blood testing results (hemoglobin, hematocrit, uric acid, creatinine, total cholesterol, triglycerides, and total testosterone), and menstrual cessation were recorded. We assessed the effects of testosterone on body composition changes and laboratory parameters, comparing a low-dose group (≤ 62.5 mg/wk) to a high-dose group (> 62.5 mg/wk). RESULTS: Of 291 participants, 188 patients (64.6%) were in the low-dose group and 103 (35.4%) in the high-dose group. Cumulative menstrual cessation rates up to 12 months were not significantly different between groups. Both groups showed a decrease in BFP and an increase in LBM during the first year of therapy, followed by a slight increase in both over the long term. The high-dose group exhibited greater LBM gains during the first year. Higher hormone doses and lower initial LBM values were associated with LBM increases at 3 and 6 months (3 mo, P = 0.006, P < 0.001; 6 mo, P = 0.015, P < 0.001). There were no long-term, dose-dependent side effects such as polycythemia or dyslipidemia. CONCLUSION: Long-term GAHT for trans men is safe and effective. Low-dose testosterone administration is sufficient to increase LBM in trans men. Higher testosterone doses can lead to an earlier increase in muscle mass.

Prognostic impact of radiological tumor burden in patients with metastatic urothelial carcinoma treated with pembrolizumab.

PURPOSE: Radiological tumor burden has been reported to be prognostic in many malignancies in the immunotherapy era, yet whether it is prognostic in patients with metastatic urothelial carcinoma (mUC) treated with pembrolizumab remains uninvestigated. We sought to assess the predictive and prognostic value of radiological tumor burden in patients with mUC. METHODS: We performed a retrospective analysis of 308 patients with mUC treated with pembrolizumab. Radiological tumor burden was represented by baseline tumor size (BTS) and baseline tumor number (BTN). Optimal cut-off value of BTS was determined as 50 mm using the Youden index (small BTS: n = 194, large BTS: n = 114). Overall (OS), cancer-specific (CSS), progression-free survival (PFS), and objective response rate (ORR) were compared. Non-linear associations between BTS and OS and CSS were evaluated using restricted cubic splines. RESULTS: Patients with large BTS were less likely to have undergone the surgical resection of the primary tumor (P = 0.01), and more likely to have liver metastasis (P < 0.001) and more metastatic lesions (P < 0.001). On multivariable analyses controlling for the effects of confounders (resection of primary tumor, metastatic site, number of metastases and lactate dehydrogenase level), large BTS and high BTN were independently associated with worse OS (HR 1.52; P = 0.015, and HR 1.69; P = 0.018, respectively) and CSS (HR 1.59; P = 0.01, and HR 1.66; P = 0.031, respectively), but not PFS. Restricted cubic splines revealed BTS was correlated with OS and CSS in linear relationships. Additionally, large BTS was significantly predictive of lower ORR and complete response rate on univariable analyses (P = 0.041 and P = 0.032, respectively), but its association disappeared on multivariable analyses. CONCLUSION: Radiological tumor burden has independent prognostic value with a linear relationship in pembrolizumab-treated patients with mUC and might help drive the earlier introduction of second-line pembrolizumab and/or switching to subsequent therapies.