Initial experience of enfortumab vedotin in a patient with metastatic urothelial carcinoma on hemodialysis: Two case reports.

Introduction: Few studies have reported on administering enfortumab vedotin to patients with metastatic urothelial carcinoma and end-stage renal disease requiring hemodialysis. Case presentation: Case 1: An 85-year-old man underwent hemodialysis for progressive renal failure 4 months after right laparoscopic radical nephroureterectomy. Case 2: A 73-year-old man underwent hemodialysis after two laparoscopic radical nephroureterectomies for recurrent urothelial carcinoma. In both cases, enfortumab vedotin was administered due to postoperative recurrence and progression despite platinum-based chemotherapy and pembrolizumab. Partial response and disease progression were observed in cases 1 and 2, respectively. Adverse events included a mild skin rash in both patients and neutropenia in Case 1, both of which resolved with symptomatic treatment. Conclusion: The efficacy and safety of enfortumab vedotin in patients with metastatic urothelial carcinoma, and end-stage renal disease undergoing hemodialysis, were confirmed.

Predictive Factors for Early Biochemical Recurrence Following Robot-assisted Radical Prostatectomy.

BACKGROUND/AIM: The primary objective of this study was to identify predictors for biochemical recurrence (BCR) within 2 years following robot-assisted radical prostatectomy (RARP). Identifying predictors will enable insights that enhance personalized patient management and facilitate the ongoing refinement of postoperative therapy strategies. PATIENTS AND METHODS: This retrospective study included patients undergoing RARP from September 2014 to January 2021. Exclusion criteria were preoperative endocrine therapy, BCR beyond 2 years post-surgery, and incomplete postoperative data. Multivariate analyses were conducted to evaluate predictors of BCR, focusing on preoperative prostate-specific antigen (PSA) level, pathological tumor (pT) stage, Gleason score (GS), extraprostatic extension (EPE), and surgical margin status. RESULTS: Among 374 patients, 40 experienced BCR within 2 years. Significant predictors of early BCR included initial PSA level ≥10 ng/ml, pT3 or greater, GS ≥8, EPE, and positive surgical margins (RM1). Multivariate analysis identified pT3 or higher, GS ≥8, and RM1 as independent risk factors for early BCR. CONCLUSION: Early BCR after RARP is significantly associated with advanced pathological stage, high GS, and positive surgical margins. These findings emphasize the need for tailored postoperative management strategies and highlight the importance of precision in surgical technique to improve patient outcomes.

Effect of HLA Genotype on Anti-PD-1 Antibody Treatment for Advanced Renal Cell Carcinoma in the SNiP-RCC Study.

Immune checkpoint blockade therapies are widely used for cancer treatment, including advanced renal cell carcinoma (RCC). This study aimed to investigate the impact of zygosity in HLA genes and individual HLA genotypes on the efficacy of an anti-PD-1 Ab, nivolumab, in treating advanced RCC. Patient enrollment was conducted across 23 institutions in Japan from August 19, 2019, to September 30, 2020, with follow-up concluding on March 31, 2021. HLA genotype imputation of HLA-A, B, and C, DQB1, and DRB1 loci was performed. Among 222 patients, the presence of at least one homozygosity of the HLA-II allele significantly improved the best objective response (hazard ratio, 0.34; 95% confidence interval, 0.21-0.96; p = 0.042). The HLA evolutionary divergence (HED) of the HLA-A and HLA-B loci was higher than the HLA-C (p < 0.0001 and p < 0.0001, respectively), with high HED of the HLA-B locus correlating to clinical benefits in nivolumab treatment (hazard ratio, 0.44; 95% confidence interval, 0.21-0.90; p = 0.024) and improving cancer-specific survival compared with the low group (p = 0.0202). Additionally, high HED of the HLA-B locus was correlated with the number of infiltrated CD8+ cells in the tumor microenvironment (correlation coefficient, 0.4042). These findings indicate that the diversity of the HLA-B locus plays a significant role in the anti-tumor effect of nivolumab treatment in advanced RCC, potentially offering insights for improved risk stratification in nivolumab treatment and leading to better medical management of advanced RCC.

Predictive factors of nivolumab plus ipilimumab treatment efficacy in metastatic renal cell carcinoma patients.

OBJECTIVE: Nivolumab plus ipilimumab is a recommended first-line therapy regimen for metastatic renal cell carcinoma. However, it is not clear which patient characteristics are associated with its effectiveness. METHODS: We retrospectively examined 67 metastatic renal cell carcinoma patients treated with nivolumab plus ipilimumab as a first-line therapy in multiple institutions from September 2018 to August 2022. We analyzed the relationships between survival outcomes and patient-related variables, including paraneoplastic symptoms. We also analyzed the relationships between changes in symptoms and parameters and outcomes. RESULTS: Of the 67 patients, 32 patients had paraneoplastic symptoms. The median progression-free survival was 14.9 months and median overall survival was 43.3 months. The objective response rate was 49.25% (33 patients), including two patients with complete response. Patients with cytoreductive nephrectomy, bone metastasis, high C-reactive protein levels and paraneoplastic symptoms were significantly correlated with short progression-free survival in the univariate analysis. Multivariate analysis of these factors showed that the presence of paraneoplastic symptoms at treatment initiation remained an independent predictor of progression-free survival. Of the 32 patients with paraneoplastic symptoms at treatment initiation, 12 patients had symptomatic improvement and 20 did not. The 1-year progression-free survival rates were significantly longer in improved patients compared with those with no improvement. CONCLUSIONS: Patients without cytoreductive nephrectomy and with bone metastasis, liver metastasis, high C-reactive protein levels and paraneoplastic symptoms were significantly correlated with shorter progression-free survival. The presence of paraneoplastic symptoms was an independent predictor of progression-free survival. Improvement in paraneoplastic symptoms may reflect the treatment efficacy of nivolumab plus ipilimumab.

Intratumoral metastasis of sigmoid colon cancer to chromophobe renal cell carcinoma: a case report.

We herein report an extremely rare case of intratumoral metastasis of colon cancer to chromophobe renal cell carcinoma. A 71-year-old woman was diagnosed with lung metastasis of sigmoid colon cancer and underwent sigmoid colon resection with D3 lymph node dissection. Preoperative contrast-enhanced computed tomography (CT) revealed a left renal tumor; however, colon resection was prioritized, and the renal tumor was placed under observation. Two years later, CT revealed enlargement of the left renal tumor, and laparoscopic partial left nephrectomy was performed 1 month later. Histopathologic examination showed that the resected renal tumor was a chromophobe renal cell carcinoma with intratumoral metastasis of colon cancer to the renal tumor center, and adjuvant chemotherapy with bevacizumab plus SOX (L-OHP + S-1) was initiated. Because of severe chemotherapy-induced fatigue and nausea, the patient was switched to bevacizumab + S-1. However, the patient's nausea did not improve after this change, and postoperative adjuvant chemotherapy was discontinued at the patient's request 4 months after the partial nephrectomy. Two months after discontinuation of chemotherapy, CT showed no renal recurrence; however, increased lung metastases and a new bone metastasis in the left sciatic bone were observed. Palliative treatment was then initiated because of severe adverse events that made it difficult to continue treatment. In patients who have multiple cancers and an increase in renal tumor size, the possibility of intratumoral metastasis to the renal tumor should be considered.

Primary signet-ring cell carcinoma of the bladder treated with laparoscopic radical cystectomy: a case report.

Primary bladder adenocarcinomas comprise 0.5-2% of all epithelial bladder neoplasms. Of these, primary signet-ring cell carcinoma of the bladder is particularly rare, accounting for 0.24% of all bladder malignancies. This tumor is frequently diagnosed at an advanced stage and has a poor prognosis. No standard treatment has yet been established. We here report a patient in whom laparoscopic cystectomy following neoadjuvant chemotherapy was effective. Our patient was a 69-year-old man who had had microscopic hematuria, undergone transurethral resection of a mass in the bladder, and been diagnosed pathologically with a primary signet-ring cell carcinoma of the bladder. No metastases were detected on computed tomography. The patient was treated with a combination of paclitaxel, cisplatin, and gemcitabine prior to undergoing laparoscopic cystectomy. The histopathological diagnosis on this operative specimen was dysplasia and no metastases were detected in the dissected lymph nodes. Complete remission has now been maintained for 9 years.

Efficacy and Safety of Brachytherapy for Localized Prostate Cancer in Renal Transplant Recipients.

BACKGROUND: Prostate cancer is common among male renal transplant recipients and can present challenges for medical management and patient survival. It is imperative to have a comprehensive understanding of available treatment options in this population to determine the most effective and safe therapies. Brachytherapy, a safe and effective treatment for localized prostate cancer, has not been sufficiently studied in this patient population. Therefore, this study aimed to evaluate the safety and effectiveness of brachytherapy in treating prostate cancer in renal transplant recipients. METHODS: We retrospectively reviewed our brachytherapy database to identify patients with a previous history of renal transplantation who underwent seed implantation for localized prostate cancer. Long-term prostate-specific antigen control and treatment-related toxicity, including graft dysfunction and urinary and rectal complications, were assessed and compared with published outcomes. Results were analyzed to evaluate the efficacy and safety of seed implantation in this patient population. RESULTS: We identified 2 patients with previous renal transplantation who underwent permanent seed implantation for localized prostate cancer. Follow-ups ranged from 53 to 57 months, and both patients remained free of prostate-specific antigen progression with normal graft function. No acute and late complications occurred. CONCLUSION: Brachytherapy is a safe and effective treatment option for post-renal transplant prostate cancer. Given the paucity of reports on brachytherapy in this population, the findings of this study, despite a small sample size, contribute to the increasing body of evidence supporting the use of brachytherapy in this patient population.

Sarcomatoid renal cell carcinoma with an inferior vena cava tumor thrombus that was completely resected by robot-assisted laparoscopic radical nephrectomy after neoadjuvant therapy nivolumab plus ipilimumab: a case report.

We here present a patient with a sarcomatoid renal cell carcinoma complicated by inferior vena cava tumor thrombus that we treated with nivolumab plus ipilimumab. This resulted in shrinkage of the tumor, enabling complete resection by robot-assisted laparoscopic radical nephrectomy. The patient is still alive with no evidence of recurrence.

Partial penectomy for severe penile ulceration caused by cholesterol crystal embolization.

Introduction: Cholesterol crystal embolism is a rare microembolic disease caused by cholesterol crystals that can present with various symptoms after vascular surgery, catheterization, or anticoagulation therapy. We report a case of penile ulceration caused by cholesterol crystal embolism. Case presentation: A 72-year-old man undergoing maintenance dialysis for end-stage renal failure presented with penile pain and a black glans ulcer. Despite low-density lipoprotein apheresis, he was referred to our hospital because of lack of improvement. Based on his medical history and clinical presentation, including artificial vascular replacement and right toe amputation, cholesterol crystal embolism was suspected and partial penectomy was performed, thus confirming the diagnosis. Penile pain resolved after surgery, and he was discharged on Day 10. Unfortunately, he died after small bowel perforation developed 2 months after surgery. Conclusion: Penile ulcers caused by cholesterol crystal embolism may indicate the severity and progression of disease and typically require surgical intervention.

Efficacy and safety of axitinib for metastatic renal cell carcinoma: Real-world data on patients with renal impairment.

OBJECTIVES: Limited information is currently available on the efficacy and safety of axitinib for metastatic renal cell carcinoma (mRCC) patients with renal impairment. Therefore, the present study investigated the efficacy and toxicity of axitinib in patients with chronic kidney disease. METHODS: Post-hoc analyses were performed on a Japanese multicenter cohort study of 477 mRCC patients who received axitinib followed by 1 or 2 regimens of systemic antiangiogenic therapy between January 2012 and December 2016. Differences in clinical characteristics and the efficacy and safety of axitinib were assessed based on pretreatment renal function. RESULTS: Patients were categorized into the following 5 renal function groups according to baseline renal function: estimated glomerular filtration rate (eGFR) ≥60 ml/min (n = 133), 45 ml/min ≤eGFR <60 ml/min (n = 153), 30 ml/min ≤eGFR< 45 ml/min (n = 130), eGFR <30 ml/min (n = 45), and dialysis (n = 16). Median progression-free survival (PFS) (95% confidence interval [CI]) in the 5 groups was 11 (8-16), 14 (11-19), 14 (10-19), 12 (8-24), and 6 (3-NR) months, respectively (p = 0.781). After adjustments for treatment-related confounders, the renal function group was not a significant prognostic factor for PFS. Objective response rates in the 5 groups were 22%, 23%, 23%, 18%, 20%, and 38%, respectively (p = 0.468). Regarding adverse events of all grades, hypertension (p = 0.0006) and renal and urinary disorders (p < 0.0001) were more frequently observed in the eGFR <30 ml/min group than in the other groups. CONCLUSIONS: Since renal function at the initiation of treatment with axitinib does not adversely affect the efficacy of VEGF-TKI therapy, clinicians do not need to avoid its administration to mRCC patients with impaired renal function in consideration of the risk of progression to end-stage renal disease.

[Clinical Outcome of Surgical Resection for Renal Cell Carcinoma with Inferior Vena Cava Tumor Thrombus].

We analyzed 45 patients who were diagnosed with renal cell carcinoma with inferior vena cava tumor thrombus (IVC) and underwent surgical resection at Nagasaki University Hospital during the 17 years from March 2003 to November 2020. The median overall survival (OS) was 68.5, 53.5, 45.7, and 20.4 months, respectively, according to the tumor thrombus level (Lv) of I, II, III and IV, with a median level of (P＝0.025). In multivariate analysis, pathological sarcomatoid changes were associated with risk of tumor recurrence in the postoperative complete remission group, and IVC thrombus level above Lv III was associated with poor prognosis in the postoperative incomplete remission group. On postoperative systemic treatment for the postoperative recurrence group and the incomplete remission group, overall survival was significantly prolonged in cases using immune checkpoint inhibitors. The results of surgical treatment of renal cell carcinoma with IVC tumor embolization were analyzed. Patients who underwent surgical resection and achieved postoperative complete remission had a relatively long prognosis with a median OS of more than 6 years. In contrast, patients with metastases, especially those with postoperative incomplete remission group, had a poor prognosis despite surgical resection, depending on the patient's situation.

Evans syndrome during pembrolizumab therapy for upper urinary tract cancer.

Introduction: Immune checkpoint inhibitors are available for the treatment of advanced urothelial carcinoma; however, serious adverse events occasionally occur. Here, we report a rare case of Evans syndrome attributed to the use of an immune checkpoint inhibitor. Case presentation: A 56-year-old man was diagnosed with left renal pelvic cancer and underwent left laparoscopic radical nephroureterectomy. Eight months postoperatively, computed tomography revealed para-aortic lymph node metastasis. Despite receiving chemotherapy, the disease progressed, and pembrolizumab was initiated. After 26 months of pembrolizumab treatment, the patient developed fever and anemia. Hematologic examination confirmed the diagnosis of Evans syndrome. He was treated with blood transfusions and corticosteroids, and gradual symptom improvement was observed. Conclusion: This report highlights the potential risk of Evans syndrome associated with immune checkpoint inhibitor treatment. Clinicians should be aware of this possibility and consider early intervention with corticosteroids.

The Incidence and Management of Cancer-Related Anorexia During Treatment with Vascular Endothelial Growth Factor Receptor-Tyrosine Kinase Inhibitors.

Cancer-related anorexia is a common complication and frequently occurs in cancer patients treated with vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs). Anorexia contributes to malnutrition, body weight loss, and cachexia in affected patients. Furthermore, patients who experience anorexia have worse outcomes than those who maintain their appetite, highlighting the importance of managing anorexia and related symptoms. However, as the causes of anorexia are both diverse and interconnected, there have been challenges in evaluating and implementing effective interventions. In this review, we described the contributing factors to cancer-related anorexia and reviewed recent literature for the frequency of anorexia symptoms in patients treated with VEGFR-TKIs. Additionally, we evaluated the evidence for current interventions and the potential benefits of multimodal and multidisciplinary approaches to care. The frequency of anorexia symptoms in patients who received VEGFR-TKIs ranged from 14%-58% for all-grade anorexia and 0%-6% for grade 3 or 4 anorexia. While many of the interventions for cancer-related anorexia have minimal benefit or adverse events, recent advances in our understanding of cancer-related anorexia suggest that multimodal therapy with multidisciplinary care is a promising avenue of investigation. Several studies currently underway are anticipated to further assess the effectiveness of multimodal approaches.

Clinical factors for tumor response, progression, and survival in nivolumab for advanced renal cell carcinoma in the SNiP-RCC study.

BACKGROUND: This study is part of the SNPs in Nivolumab PD-1 inhibitor for RCC (SNiP-RCC). Here we aimed to reveal clinical factors for tumor response, progression, and survival in nivolumab for advanced clear cell renal cell carcinoma (RCC) in Japanese patients. METHODS: We included patients from 23 institutions in Japan. We evaluated the objective response, radiographic progression-free survival (PFS), overall survival (OS), and treatment-related grade ≥ 3 (serious adverse events [SAEs]). RESULTS: We included 222 patients. The median age was 69 years (interquartile range 62-74 years), and 71% of the patients were male. Pancreas metastasis, lung metastases, prior cytokine therapy, and SAEs, were associated with objective response. The median PFS was 18 months. Liver metastases (hazard ratio [HR], 1.61), age ≥ 75 (HR, 0.48), previous resection of primary sites (HR, 0.47), and SAEs (HR, 0.47) were independent prognostic factors for PFS. Karnofsky Performance Status <70 (HR, 2.90), high platelets (HR, 4.48), previous resection of primary sites (HR, 0.23), and pathological grade (HR, 0.19 for grade 2 and HR, 0.12 for grade 3) were independent prognostic factors for OS. SAEs were reported in 45 (20.3%) cases. In the group of patients with prior nephrectomy, SAEs were associated with objective response, PFS, and OS. CONCLUSION: The SNiP-RCC study identified clinical parameters correlated with treatment outcomes in Japanese patients with priorly treated advanced clear cell RCC undergoing nivolumab monotherapy.

Comprehensive investigation of clinicopathological and immunological features to determine prognostic impact in metastatic renal cell carcinoma: The JEWEL study.

OBJECTIVES: Current prognostic models for metastatic renal cell carcinoma (mRCC) are likely inaccurate due to recent treatment advances and improved survival outcomes. The JEWEL study used a data set from patients who received tyrosine kinase inhibitors (TKIs) to explore the prognostic impact of the tumor immune environment in the absence of immune checkpoint inhibitor intervention. METHODS: The primary analysis population comprised 569 of the 770 Japanese patients enrolled in the ARCHERY study who received first-line TKIs. Multivariable Cox proportional hazard models were used to identify factors associated with the primary (overall survival [OS]) and secondary outcomes (treatment duration) using 34 candidate explanatory variables. RESULTS: Median OS was 34.1 months (95% CI, 30.4-37.6) in the primary analysis population. A considerable negative prognostic impact (descriptive p ≤ 0.0005) on OS was seen with lactate dehydrogenase (LDH) >1.5 × upper limit of normal (adjusted HR [aHR], 3.30; 95% CI, 2.19-4.98), Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 (aHR, 2.14; 95% CI, 1.56-2.94), World Health Organization (WHO)/International Society of Urological Pathology (ISUP) Grade 4 (aHR, 1.89; 95% CI, 1.43-2.51), C-reactive protein (CRP) level ≥0.3 (aHR, 1.78; 95% CI, 1.40-2.26), and age ≥75 years (aHR, 1.65; 95% CI, 1.24-2.18) in the multivariable analysis. PD-L1 and immunophenotype affected OS in univariable analyses but were not selected in the multivariable model as explanatory variables. CONCLUSIONS: JEWEL identified sex, age, ECOG PS, liver and bone metastases, CRP levels, WHO/ISUP grade, LDH, and albumin levels as key prognostic factors for OS after first-line TKI therapy for mRCC.

[A Retrospective Study on the Malignancies after Renal Transplantation].

Detection of post-transplant malignant tumors and the analysis of the associated risk factors is important for monitoring the progress after renal transplantation. In this study, we retrospectively examined the medical records of 298 patients who underwent renal transplantation at two facilities in Nagasaki Prefecture (Nagasaki University Hospital and National Hospital Organization Nagasaki Medical Center). Of the 298 patients, 45 (15.1%) patients had developed malignant tumors with 50 lesions. The most common type of malignant tumor was skin cancer (eight patients; 17.8%), followed by renal cancer (six patients; 13.3%), and pancreatic cancer and colorectal cancer, (four patients; 9.0% each). Five patients (11.1%) had multiple cancers, four of whom had skin cancer. The cumulative incidence within 10 and 20 years after renal transplantation was 6.0 and 17.9%, respectively. Univariate analysis identified age at transplantation and administration of cyclosporine and rituximab as risk factors, while multivariate analysis identified age at transplantation and administration of rituximab as independent factors. The administration of rituximab was associated with the development of malignant tumors. However, further investigation is required to establish the association with post-transplant malignant neoplasms.

Effect of genetic polymorphisms on outcomes following nivolumab for advanced renal cell carcinoma in the SNiP-RCC trial.

BACKGROUND: Anti-PD-1 antibodies are widely used for cancer treatment including advanced renal cell carcinoma (RCC). However, their therapeutic and adverse effects vary among patients. This study aimed to identify genetic markers that predict outcome after nivolumab anti-PD-1 antibody treatment for advanced RCC. METHODS: This study was registered on the website of the University Hospital Medical Information Network (protocol ID, UMIN000037739). Patient enrollment was conducted at 23 institutions in Japan between August 19, 2019, and September 30, 2020. Patient follow-up ended on March 31, 2021. Patients were treated with nivolumab for advanced clear cell RCC. A genome-wide association study was performed in the development set, while genotyping of target regions in the validation set was undertaken. Single nucleotide polymorphisms (SNPs) in genes of interest CD274, PDCD1LG2 and PDCD1 were genotyped in the combined set. The primary endpoint was the association of SNPs with objective response following nivolumab treatment. As secondary endpoints, the associations of SNPs with radiographic progression-free survival (rPFS) and treatment-related grade ≥ 3 adverse events (AEs) were evaluated. RESULTS: A genome-wide association study followed by a validation study identified that SNPs in FARP1 (rs643896 and rs685736) were associated with objective response and rPFS but not AEs following nivolumab treatment. Furthermore, SNPs in PDCD1LG2 (rs822339 and rs1411262) were associated with objective response, rPFS, and AEs following nivolumab treatment. Genetic risk category determined according to the number of risk alleles in SNPs (rs643896 in FARP1 and rs4527932 in PDCD1LG2) excellently predicted objective response and rPFS in nivolumab treatment. CONCLUSION: This study revealed that SNPs in FARP1 and PDCD1LG2 were correlated with outcome in nivolumab treatment. The use of these SNPs may be beneficial in selecting appropriate treatment for individual patients and may contribute to personalized medicine.

Prognostic value of PD-L1 expression in recurrent renal cell carcinoma after nephrectomy: a secondary analysis of the ARCHERY study.

BACKGROUND: Nephrectomy is a curative treatment for localized renal cell carcinoma (RCC), but patients with poor prognostic features may experience relapse. Understanding the prognostic impact of programmed death-ligand 1 (PD-L1) expression in patients who underwent nephrectomy for RCC may aid in future development of adjuvant therapy. METHODS: Of 770 surgical specimens collected from Japanese patients enrolled in the ARCHERY study, only samples obtained from patients with recurrent RCC after nephrectomy were examined for this secondary analysis. Patients were categorized into low- and high-risk groups based on clinical stage and Fuhrman grade. Time to recurrence (TTR) and overall survival (OS) were analyzed. RESULTS: Both TTR and OS were shorter in patients with PD-L1-positive than -negative tumors (median TTR 12.1 vs. 21.9 months [HR 1.46, 95% CI 1.17, 1.81]; median OS, 75.8 vs. 97.7 months [HR 1.32, 95% CI 1.00, 1.75]). TTR and OS were shorter in high-risk patients with PD-L1-positive than -negative tumors (median TTR 7.6 vs. 15.3 months [HR 1.49, 95% CI 1.11, 2.00]; median OS, 55.2 vs. 83.5 months [HR 1.53, 95% CI 1.06, 2.21]) but not in low-risk patients. CONCLUSIONS: This ARCHERY secondary analysis suggests that PD-L1 expression may play a role in predicting OS and risk of recurrence in high-risk patients with localized RCC. CLINICAL TRIAL REGISTRATION: UMIN000034131.

Pathological Significance of Kidney and Brain Expressed Protein (KIBRA) in Clear Cell Renal Cell Carcinoma.

BACKGROUND/AIM: Kidney and brain expressed protein (KIBRA), a member of the WW domain-containing protein family, has an important role in tumour growth and progression in various cancers. However, the pathological significance of KIBRA expression in clear cell renal cell carcinoma (ccRCC) tissues is not fully understood. The aim of this study was to clarify the pathological significance and prognostic roles of KIBRA expression in patients with ccRCC. MATERIALS AND METHODS: KIBRA immunoreactivity, proliferation index (PI; with anti-Ki-67 antibody), apoptotic index (AI; using anti-cleaved caspase-3), and large tumour suppressor kinases (LATS-2) were evaluated in 157 ccRCC specimens by immunohistochemistry. Fifty normal kidney tissues were also evaluated as controls. The relationships between KIBRA expression and these cancer-related variables as well as clinicopathological features and survival were analysed. RESULTS: Moderate to strong immunoreactivity of KIBRA was identified in all normal kidney tissues; however, ccRCC cells with strong KIBRA expression was rare. The immunoreactivity score (IRS) of KIBRA was negatively associated with grade, T stage, tumour diameter, and metastasis. Kaplan-Meier survival curves showed that high KIBRA expression was a favourite predictor for overall survival. KIBRA IRS was negatively associated with PI and positively associated with the IRS of LATS-2 by univariate analysis. In addition, multivariate analysis showed that KIBRA was significantly associated with PI. CONCLUSION: KIBRA demonstrated important roles as a tumour suppressor in ccRCC. In addition, its expression was significantly associated with survival in these patients. Several such KIBRA-related functions were speculated to be modulated by cancer cell proliferation and LATS-2.