Renal cell carcinoma in patients with end-stage renal disease: relationship between histological type and duration of dialysis

Efficacy of 18F-Fluorodeoxyglucose positron emission tomography/computed tomography for detecting renal cell carcinoma in patients with end-stage renal disease

PURPOSE

Dialysis patients are at an increased risk of developing renal cell carcinoma (RCC); however, differentiating between RCC and benign cysts can sometimes be difficult using modalities, such as computed tomography (CT) and ultrasonography. 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET)/CT efficiently detects malignant tumors; however, physiological accumulation of FDG in the kidney limits its efficacy in detecting renal tumors. However, in patients with severely impaired renal function, the renal accumulation of FDG is decreased, possibly improving the detection of renal malignancies in this patient population. This study evaluated the usefulness of FDG-PET/CT as a screening tool for detecting RCC in patients with end-stage renal disease.

MATERIALS AND METHODS

This prospective study recruited 150 participants from 2012 to 2016 who were on dialysis or underwent renal transplantation and were on dialysis until transplantation. FDG-PET/CT was performed to screen for RCC. Three radiologists independently evaluated the images. No protocol was defined for the additional management of positive examinations, leaving decisions to the discretion of each participant. Negative examinations were observed until the end of 2019.

RESULTS

In total, 150 participants (mean age, 58 ± 13 years; 105 men) underwent FDG-PET/CT. Twenty patients (13.4%) were diagnosed as positive. Fifteen patients underwent additional examinations and/or procedures, and RCC was found in seven patients. Of the four patients who underwent surgical resection, the pathological results were clear cell RCC in one, papillary RCC in one, and acquired cystic disease-associated RCC in two. Two participants were diagnosed with RCC on bone biopsy, and one was diagnosed on dynamic CT but opted for observation. The sensitivity, specificity, and negative predictive value were 100%, 93.9%, and 100%, respectively.

CONCLUSION

FDG-PET/CT was useful for detecting RCC in patients with end-stage renal disease. Our findings show the potential use of FDG-PET/CT as a screening tool for RCC in this patient population.

Renal Cell Carcinoma in End-Stage Kidney Disease and the Role of Transplantation

Kidney transplant patients have a higher risk of renal cell carcinoma (RCC) compared to non-transplanted end-stage kidney disease (ESKD) patients. This increased risk has largely been associated with the use of immunosuppression; however, recent genetic research highlights the significance of tissue specificity in cancer driver genes. The implication of tissue specificity becomes more obscure when addressing transplant patients, as two distinct metabolic environments are present within one individual. The oncogenic potential of donor renal tissue is largely unknown but assumed to pose minimal risk to the kidney transplant recipient (KTR). Our review challenges this notion by examining how donor and recipient microenvironments impact a transplant recipient's associated risk of renal cell carcinoma. In doing so, we attempt to encapsulate how ESKD-RCC and KTR-RCC differ in their incidence, pathogenesis, outcome, and approach to management.

Genomic features of renal cell carcinoma developed during end-stage renal disease and dialysis

Patients with end-stage renal disease (ESRD) or receiving dialysis have a much higher risk for renal cell carcinoma (RCC), but carcinogenic mechanisms and genomic features remain little explored and undefined. This study's goal was to identify the genomic features of ESRD RCC and characterize them for associations with tumor histology and dialysis exposure. In this study, we obtained 33 RCCs, with various histological subtypes, that developed in ESRD patients receiving dialysis and performed whole-genome sequencing and transcriptome analyses. Driver events, copy-number alteration (CNA) analysis and mutational signature profiling were performed using an analysis pipeline that integrated data from germline and somatic SNVs, Indels and structural variants as well as CNAs, while transcriptome data were analyzed for differentially expressed genes and through gene set enrichment analysis. ESRD related clear cell RCCs' driver genes and mutations mirrored those in sporadic ccRCCs. Longer dialysis periods significantly correlated with a rare mutational signature SBS23, whose etiology is unknown, and increased mitochondrial copy number. All acquired cystic disease (ACD)-RCCs, which developed specifically in ESRD patients, showed chromosome 16q amplification. Gene expression analysis suggests similarity between certain ACD-RCCs and papillary RCCs and in TCGA papillary RCCs with chromosome 16 gain identified enrichment for genes related to DNA repair, as well as pathways related to reactive oxygen species, oxidative phosphorylation and targets of Myc. This analysis suggests that ESRD or dialysis could induce types of cellular stress that impact some specific types of genomic damage leading to oncogenesis.

Tumors masquerading as type 2 papillary renal cell carcinoma: pathologists' ever-expanding differential diagnosis for a heterogeneous group of entities

Although papillary renal cell carcinoma has historically been classified as either type 1 or type 2, data from The Cancer Genome Atlas (TCGA) has demonstrated significant genomic heterogeneity in tumors classified as "type 2 papillary renal cell carcinoma" (T2PRCC). Papillary renal cell carcinoma is expected to have a favorable clinical course compared to clear cell renal cell carcinoma (CCRCC). However, tumors with poor outcome more similar to CCRCC were included in the T2PRCC cohort studied by the TCGA. The differential diagnosis for T2PRCC includes a variety of other renal tumors, including aggressive entities such as TFE3 translocation-associated renal cell carcinoma, TFEB-amplified renal cell carcinoma, fumarate hydratase-deficient renal cell carcinoma, high-grade CCRCC, and collecting duct carcinoma. Accurate classification of these tumors is important for prognostication and selection of therapy.

Transplant or dialysis: What’s the better choice for RCC-induced ESRD patients? A 20-year analysis of OPTN/UNOS data

Purpose

The incidence of end-stage renal disease (ESRD) caused by renal cell carcinoma (RCC) is increasing with the high prevalence of RCC as well as those with treatment-related renal function impairment. Worries about tumor recurrence after transplant-related immunosuppression hinder the recommendation of kidney transplantation for RCC-induced ESRD patients. However, no direct analysis has been performed to identify whether kidney transplantation can offer better survival than maintaining dialysis.

Materials and methods

This retrospective population-based cohort study was based on Organ Procurement and Transplantation Network data released in March 2021. Characteristics and outcomes were compared, including the patient and graft survival of candidates and recipients with RCC-induced ESRD etiology as well as other primary diseases.

Results

Patients with RCC-induced ESRD were older; more likely to be male, White, and obese; and more likely to have a history of diabetes and dialysis. They also had higher creatinine levels, more delayed graft function, more primary non-function, and higher Kidney Donor Profile Index score donors, compared with the glomerulonephritis (GN) group. While waiting, RCC candidates suffered the worst outcomes of all groups, a 44% (adjusted hazard ratio [aHR], 1.44 [1.27–1.62]) higher risk of removal than GN patients. After transplantation, RCC recipients demonstrated comparable patient survival and better graft survival (p=0.21 and p=0.13, respectively). Compared with still-waiting RCC patients, the RCC recipients who received kidney transplants had significantly better outcomes (13.6 [9.3–17.8] vs. 61 [52–68.4] %), decreasing the death or deteriorating risk by 84% (aHR, 0.16 [0.13–0.20]).

Conclusions

Patients with RCC-induced ESRD can dramatically benefit from kidney transplantation. Hence, these patients should not be limited to transplantation by strict strategies or a delayed waiting time out of their malignancy history.

Acquired cystic disease-associated renal cell carcinoma: A clinicopathologic study of eight tumors with clinical follow-up

Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is the major RCC subtype in patients with end-stage renal disease, specifically those with ACD on dialysis. Three patients with a total of eight tumors have been selected. The aim of this study was to analyze clinicopathologic, immunohistochemical, and prognostic features of eight ACD-RCCs. Three patients with end-stage renal disease (ESRD) were in the age range of 34-45 years and being treated with hemodialysis. All eight tumors were resected by radical nephrectomy. Two patients had a single ACD-RCC, while one patient had bilateral and multifocal ACD-RCCs. Microscopically, combinations of architectural patterns were identified in all tumors. Intracytoplasmic and intraluminal vacuoles, eosinophilic granular cytoplasm, and prominent nucleoli were universal characteristics of these tumors. Atypical cysts were present in three out of four resected kidneys. Immunohistochemistry (IHC) staining revealed all tumors were strongly and diffusely positive for pan-cytokeratin and α-methylacyl-CoA racemase and variably positive for CK7, CD10, PAX8, EMA, vimentin, cytokeratin, high molecular weight cytokeratin (CK HMW). All cases were negative for Napsin A, CK20, CD117, and CD57. After an average follow-up of 27.5 months (range 3-54 months), all our patients are alive without neoplastic (metastatic or recurrent) disease. Our study supports the finding that ACD-RCC has specific morphologic features and a broad spectrum of architectural patterns. We have found that the immunoprofile of ACD-RCC is distinct from that in other RCCs; however, nonspecific and interpretation of microscopic features in the context of the clinical history can aid the diagnosis. We confirm also the favorable prognosis in ACD-RCC.

Comparable survival outcome between acquired cystic disease associated renal cell carcinoma and clear cell carcinoma in patients with end-stage renal disease: a multi-institutional central pathology study

Acquired cystic disease (ACD) associated renal cell carcinoma (RCC) is designated as a new subtype unique to patients with end-stage renal disease (ESRD) according to the 2016 World Health Organization (WHO) classification. However, the oncological outcomes of the prognostic factors for patients with this subtype are not fully understood. In the present study, we compared the survival of ACD associated RCC patients who underwent nephrectomy with that of patients with other histological subtypes who developed ESRD. Over 378 patients who underwent nephrectomy at three Japanese institutes between 1987 and 2016 were included in this study. A central pathologist reviewed the sections from all patients according to the 2016 WHO classification. The central pathological review showed a clear cell subtype in 165 patients (43.6%), ACD associated RCC in 112 (29.6%), papillary in 61 (16.1%), and others in 40 (10.7%). The proportion of patients with pathological stage 1 was extremely high in both clear cell and ACD associated RCC cohorts (86.6%, 85.7%). The cancer specific survival (CSS) and recurrence free survival rates of patients with ACD associated RCC were comparable with those with clear cell carcinoma and significantly better than those with the papillary subtype. The factors predictive of unfavourable outcomes were long dialysis duration, tumour size, pathological stage, grade 4 tumour, and the presence of lymphovascular invasion or a sarcomatoid component. Patients with a pre-operative dialysis duration of 20 years or longer showed a significantly worse CSS than other patients, probably owing to sarcomatoid differentiation and stage migration during the advanced stages. In conclusion, this study included the largest number of patients with ACD associated RCC, showing a survival similar to that of clear cell histology patients with ESRD, except for the rarity of late recurrence. ACD associated RCC was not as indolent as initially recognised when patients were on long term dialysis.

Paneth-like cells in renal cell carcinomas and in cysts associated with acquired cystic kidney disease: Clinicopathologic analysis, comparative study and description of precursor lesions

Paneth-like cells (PLCs) are different from Paneth cells (PCs) and contain Paneth-like granules, which have been reported in non-neoplastic conditions and in neoplasms of various organs. PLCs have been reported in clear cell renal cell carcinoma (CCRCC), but not in non-CCRCC, including acquired cystic disease-associated renal cell carcinoma (ACD-RCC). We analyzed clinicopathological features of 24 acquired cystic disease-associated renal cell carcinoma (ACD-RCC) with PLCs (ACD-RCCP+) and compared with those of 23 ACD-RCCs without PLCs (ACD-RCCP-). Approximately half of ACD-RCCs had PLCs and that almost all kidneys harboring ACD-RCC had cysts with PLCs. The fact that many ACD-RCCs and the cysts had PLCs is further evidence that the cyst with vacuoles and complex architecture might be a precursor lesion for ACD-RCC. The presence of PLCs may provide additional morphologic clue for distinguishing ACD-RCC from PRCC in challenging differential diagnostic workup in acquired cystic disease of the kidney setting.

Comprehensive Clinicopathologic Analyses of Acquired Cystic Disease-associated Renal Cell Carcinoma With Focus on Adverse Prognostic Factors and Metastatic Lesions

Acquired cystic disease of kidney-associated renal cell carcinoma (ACD-RCC) is a distinct subtype of renal cell carcinoma with unique morphologic and clinicopathologic features. Generally, ACD-RCC is regarded as an indolent tumor; however, prognostic and outcomes data have been conflicted by the limited and relatively low number of cases with patient follow-up or adverse events. In this study, we focused on the histology of metastatic lesions and identifying prognostic factors associated with metastatic progression. From 32 cases in the cohort, 9 patients had metastasis [ACD-RCC (M+)] and 23 patients were without metastasis [ACD-RCC (M-)]. The median age of patients was 52 years; right side, n=10; left side, n=18; bilateral, n=4; median tumor size=2.6 cm; median hemodialysis duration=17 y; and the median duration of follow-up was 50 mo. Immunohistochemistry showed ACD-RCC to be racemase positive and CK7 negative to focally positive within tumor cells, with consistent positivity for renal histogenesis-associated markers (PAX8 and RCC antigen); S100A1 was a less reliable marker at metastatic sites. All metastatic ACD-RCC except 2 cases involved lymph nodes (para-aortic, renal hilar, subclavicular). Overall, 6/9 (67%) had visceral metastasis to sites including lung (n=3), liver (n=3), bone (n=5), stomach (n=1), and brain (n=1). In total, 5/9 (56%) metastatic tumors had distinctive cystic growth pattern at the metastatic site; intriguingly metastatic tumors had intrametastatic oxalate crystal deposition, a pathognomonic feature associated with primary tumors. Four of nine (44%) patients with ACD-RCC (M+) had fatal outcomes due to metastatic disease. Clinically significant adverse prognostic features associated with metastasis [median follow-up 47 mo, ACD-RCC (M+) vs. ACD-RCC (M-), 50 mo] included: duration of hemodialysis (≥20 vs. <20 y, P=0.0085) and tumor necrosis (P=0.049). Because of sufficient overlap between these parameters, the study was not able to identify parameters that would be reliable in further management strategies, in clinical settings. Our data indicate that ACD-RCC is a tumor which has distinct metastatic potential with nodal and visceral tropism and proclivity for cystic morphology at metastatic sites; this is the first report of the presence of oxalate crystals in metastatic tumors. Our data suggest that ACD-RCC patients with prolonged hemodialysis and tumoral coagulative necrosis require additional surveillance in view of the association of these parameters with metastatic progression.

Renal Cell Tumors: Molecular Findings Reshaping Clinico-pathological Practice

Over the past 20 years, the number of subtypes of renal epithelial cell neoplasia has grown. This growth has resulted from detailed histological and immunohistochemical characterization of these tumors and their correlation with clinical outcomes. Distinctive molecular phenotypes have validated the unique nature of many of these tumors. This growth of unique renal neoplasms has continued after the 2016 World Health Organization (WHO) Classification of Tumours. A consequence is that both the pathologists who diagnose the tumors and the clinicians who care for these patients are confronted with a bewildering array of renal cell carcinoma variants. Many of these variants have important clinical features, i.e. familial or syndromic associations, genomics alterations that can be targeted with systemic therapy, and benignancy of tumors previously classified as carcinomas. Our goal in the review is to provide a practical guide to help recognize these variants, based on small and distinct sets of histological features and limited numbers of immunohistochemical stains, supplemented, as necessary, with molecular features.

Outcome of renal cell carcinoma in patients on dialysis compared to non-dialysis patients

PURPOSE

To investigate the impact of hemodialysis on survival in renal cell carcinoma (RCC) patients.

METHODS

We studied 388 patients who underwent radical or partial nephrectomy for RCC at Toranomon Hospital from 2005 to 2013. Survival curves were drawn according to the Kaplan-Meier method and compared with the log-rank test. Multivariate analysis was performed using the Cox proportional hazards regression model to assess the prognostic influence of hemodialysis on cancer-specific survival.

RESULT

Of the 388 patients, 66 were on hemodialysis and 322 were not on dialysis. In the hemodialysis patients, incidental diagnosis of RCC was less frequent than in the non-dialysis patients. In addition, RCC was more likely to be multicentric (41% vs 1.2%), bilateral (14% vs 0.6%), and papillary (18% vs 7%) in hemodialysis patients. Moreover, tumors were smaller, the stage was lower, and the Fuhrman nuclear grade was higher in the patients on hemodialysis. The 5-year cancer-specific survival rate was 82.8% for hemodialysis patients and 93.5% for nondialysis patients. Multivariate analysis indicated that hemodialysis, stage, and Fuhrman nuclear grade were independent prognostic factors for RCC.

CONCLUSIONS

This study suggested that hemodialysis was an independent prognostic factor for cancer-specific survival in RCC patients, along with the tumor stage and Fuhrman nuclear grade.

Bilateral and Multifocal Acquired Cystic Disease-Associated Renal Cell Carcinomas in Patient With End-Stage Renal Disease Caused by Systemic Lupus Erythematosus

The disease entity of acquired cystic disease-associated renal cell carcinoma (ACD-RCC) has been recently incorporated into the international renal tumor classification. We performed a clinicopathologic study of a patient with bilateral and multifocal ACD-RCCs. The patient received long-term hemodialysis in the end-stage renal disease caused by systemic lupus erythematous. First left-sided nephrectomy and after 6 months right-sided nephrectomy was performed. None of the preoperative radiologic examinations revealed lesions suspected of malignancy. All of the 6 tumors were incidentally found on grossing radical nephrectomy specimens. Histologically, tumors consisted of a variety of growth patterns (including papillary and cribriform) of neoplastic cells with granular eosinophilic cytoplasm and intratumoral oxalate crystals. Neoplastic cells were positive for AMACR, CK AE1/AE3, and CD10; focally positive for CK7; and negative for PAX8. Seven months after the first nephrectomy, the patient still receives dialysis. There was no evidence of lymph node or distant metastases.

Nomograms for predicting overall and cancer-specific survival in patients with papillary renal cell carcinoma: a population-based study using SEER database

BACKGROUND

To establish and validate nomograms for predicting the overall survival (OS) and cancer-specific survival (CSS) in patients with papillary renal cell carcinoma (pRCC).

METHODS

Patients diagnosed with pRCC between 2010 and 2014 in the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively included in this study and divided into training and validation groups randomly. Uni- and multivariate Cox regression analyses were used to identify significant variables related to OS and CSS in the training group. Based on results of multivariate Cox regression analysis, nomograms for 3- and 5-year CSS and OS were established, respectively. Additionally, Kaplan-Meier (KM) survival curves were produced to learn the actual effects of different variables. Finally, the nomograms were evaluated both in the training group and the validation group using the area under the receiver operating characteristic (ROC) curve, the concordance index (C-index) and calibration curves.

RESULTS

A total of 4,859 eligible patients were enrolled, with 3,403 categorized into the training group and 1,456 into the validation group. Seven factors [age, T stage, N stage, M stage, use of surgery/lymph node removal (LNR) and insurance status] were significantly related to OS and seven factors (age, T stage, N stage, M stage and use of surgery/chemotherapy/LNR) were significantly associated with CSS. These factors were eventually included in the predictive nomograms. The C-indexes for OS in the training and validation groups were 0.764 and 0.723 respectively, and 0.859 and 0.824 for CSS. The 3- and 5-year AUCs for OS were 0.779 and 0.752 in the training cohort, and 0.749 and 0.722 in the validation cohort. Similarly, 3- and 5-year AUCs for OS were 0.871 and 0.844 in the training cohort, and 0.853 and 0.822 in the validation group. Finally, the calibration curves suggested that the predictive nomograms had a good consistency between the observed and the predicted survival.

CONCLUSIONS

It was the first time to develop nomograms to predict the survival outcomes of pRCC patients. The prognostic nomograms were reliable with high accuracy, which might have guiding significance for clinical practice.

The effect of renal function change on renal cell carcinoma patients with tumor thrombus after nephrectomy and thrombectomy: a large Chinese center experience

Background

To explore the influencing factors of perioperative renal function change and their relationship with prognosis on renal cell carcinoma (RCC) patients with tumor thrombus after nephrectomy and thrombectomy.

Methods

The clinical and pathological data of 135 patients with RCC and tumor thrombus, who underwent nephrectomy and thrombectomy at Peking University Third Hospital from May 2015 to July 2018, was retrospectively analyzed. Absolute change in estimated glomerular filtration rate (eGFR) (ACE) and percent change in eGFR (PCE) were calculated by preoperative and postoperative renal function. Linear regression analysis was used to explore the influencing factors of ACE and PCE, and logistic regression analysis was used to explore the influencing factors of worse postoperative renal function [eGFR≤60 mL/(min × 1.73 m^2)]. Cancer-specific survival (CSS) was estimated by Kaplan-Meier method and multivariate Cox regression, which were used to explore the effect of ACE and PCE on prognosis.

Results

Of all the 135 patients, 101 patients (74.8%) were male and 34 patients (25.2%) were female. The mean preoperative eGFR was 73.9 ± 21.8 mL/(min × 1.73 m^2) and postoperative eGFR was 69.5 ± 25.2 mL/(min × 1.73 m^2). In multivariate linear regression analysis, preoperative eGFR (P < 0.001) and pathological type (P = 0.038) were significant predictive factors of ACE. In aspect of PCE, preoperative eGFR (P < 0.001) and pathological type (P = 0.002) were significant predictors. In multivariate logistic regression analysis, preoperative eGFR (P = 0.016) was the only risk factor of predicting worse postoperative renal function. During follow-up, 22 patients (16.3%) were dead due to RCC. According to ROC analysis, the cut off value of ACE and PCE was 13.9 and 0.16, respectively. ACE> 13.9 and PCE > 0.16 indicated worse CSS (P = 0.006 and P = 0.047, respectively). However, in multivariate Cox regression analysis of several related factors, perinephric tissues invasion (P = 0.001), sarcomatoid differentiation (P = 0.001) and ACE> 13.9 (P = 0.002) were significant prognostic factors for CSS. PCE > 0.16 seemed to be not (P = 0.055).

Conclusion

We explored several clinicopathological risk factors of predicting renal function change and their relationship with prognosis of RCC patients with tumor thrombus after nephrectomy and thrombectomy. The renal function change, which was associated with preoperative eGFR and pathological type, was prognostic risk factor for CSS and ACE> 13.9 indicated the worse prognosis.

Acquired Cystic Disease-associated Renal Cell Carcinoma (ACKD-RCC)-like Cysts

Acquired cystic disease-associated renal cell carcinoma (ACKD-RCC), originally described by Tickoo and colleagues, is found exclusively in patients with end-stage renal disease. Tickoo and colleagues noted: "Many of the tumors (16 of 24 dominant tumors) appeared to arise in a cyst, most often completely filling the cystic space. The cells lining such cysts were morphologically similar to those in the rest of the tumor." Subsequent literature lacks analysis of cysts lined by cells identical to ACKD-RCC, yet lacking areas of solid growth. The current study evaluates 16 cases ACKD-RCC-like cysts. All specimens were nephrectomies and occurred in the setting of end-stage renal disease. Of the 16 cases, 9 were in men. Patient's ages ranged from 32 to 66 years (median: 57). The cysts ranged in size from 0.2 to 2.5 cm. Twelve cases had unilateral cysts with the remaining 4 seen in both kidneys. Nine cysts were multilocular, 6 unilocular, and 1 consisted of closely clustered cysts. The atypical cysts showed architectural variation. One cyst was lined by a single layer of atypical cells (1/16), whereas in the majority these were either focally lined by 2 to 4 cell layers of atypical cells (6/16 cases) or showed occasional short papillary formations (9/16). Calcium oxalate crystals were noted in cyst walls in 7/16 cases. A total of 12/16 cases had separate RCCs (2 cases with 2 RCCs each; 1 case with 3). Carcinoma ranged in size from 3 mm to 5 cm in the largest dimension: 4 were pT1 ACKD-RCC; 5 were pT1 papillary RCC; 5 were pT1 clear cell papillary RCC; 1 was pT3 clear cell RCC; and 1 pT1 unclassified. Our study formally analyzes for the first time in the literature atypical cysts lined with vacuolated cells with eosinophilic cytoplasm that are likely the earliest precursors of ACKD-RCC. When these cysts are encountered, especially ones that are multilocular or clustered, they may be misdiagnosed as ACKD-RCC. ACKD-RCC-like cysts should be recognized as a distinct entity from ACKD-RCC, defined by the lack of any solid nodular growth within the cyst.

Acquired Cystic Disease-associated Renal Cell Carcinoma (ACD-RCC): A Multiinstitutional Study of 40 Cases With Clinical Follow-up

The incidence of renal cell carcinoma (RCC) is known to be higher in patients with end-stage renal disease, including those with acquired cystic kidney disease due to dialysis. Acquired cystic disease (ACD)-associated RCC was recently incorporated into the 2016 WHO Classification of Tumors of the Urinary System and Male Genital Tract as a distinct entity and is reportedly the most common RCC arising in end-stage renal disease. In this study, we sought to further describe clinicopathologic findings in a large series of ACD-RCC, emphasizing histologic features, immunophenotype, clinical outcome, and patterns of disease spread. We collected 40 previously unpublished cases of ACD-RCC with mean clinical follow-up of 27 months (median, 19 mo; range, 1 to 126 mo). Mean tumor size was 2.7 cm (median, 2.4 cm), and 32 tumors (80%) were confined to the kidney (pT stage less than pT3a). International Society of Urological Pathology grade was 3 in 37 cases (92.5%), grade 2 in 1 case (2.5%), and grade 4 in 2 cases (5%). Architectural variability among ACD-RCC was common, as 39 cases (98%) showed varying combinations of tubular, cystic, solid, and/or papillary growth. ACD-RCC frequently occurred in association with other renal tumor subtypes within the same kidney, including papillary RCC (14 patients), papillary adenomas (7 cases), clear cell papillary RCC (5 cases), clear cell RCC (1 case), and RCC, unclassified type (1 case). A previously undescribed pattern of perinephric and renal sinus adipose tissue involvement by dilated epithelial cysts with minimal or absent intervening capsule or renal parenchyma was identified in 20 cases (50%); these cysts were part of the tumor itself in 5 cases (25%) and were part of the non-neoplastic acquired cystic change in the background kidney in the remaining 15 cases (75%). Of the 24 cases (60%) with tissue available for immunohistochemical stains, 19 (79%) were positive for PAX8, 20 (83%) showed negative to patchy expression of cytokeratin 7, and 24 (100%) were both positive for AMACR and negative for CD117. Fumarate hydratase expression was retained in all tumors, including those with nuclear features resembling fumarate hydratase-deficient RCCs. Of the 36 patients (90%) with available follow-up information, 4 (11%) experienced adverse events: 2 patients developed a local recurrence, 1 patient experienced multiple visceral metastases and subsequently died of disease, and 1 patient developed metastases to regional lymph nodes only. One local recurrence and the lymph node only metastasis both had an unusual, exclusively cystic pattern of growth. In summary, we present the largest clinicopathologic series of ACD-RCC to date and describe previously unreported cystic patterns of local soft tissue involvement and recurrence/metastases.

Mucinous Tubular and Spindle Cell Carcinoma: A Review of Histopathology and Clinical and Prognostic Implications

Mucinous tubular and spindle cell carcinomas are rare kidney tumors with generally indolent behavior. As the name suggests, classic histomorphology reveals bland spindle cells, tubules, and mucinous stroma. Uncommon histologic features include mucin-poor stroma, high nuclear grade, cellular pleomorphism, and presence of necrosis. Rare cases can show aggressive growth and distant metastasis. Mucinous tubular and spindle cell carcinoma has characteristic chromosomal abnormalities and the molecular signature remains the same, irrespective of the varied histomorphology.

Recurrence of Renal Cell Cancer After Renal Transplantation in a Multicenter French Cohort

BACKGROUND

Renal cancer accounts for 3% of adult malignancies; renal cell carcinoma (RCC) represents 80% of all renal cancers, and is characterized by late recurrences. Recurrences after kidney transplantation are associated with a high mortality rate. We aimed to determine if recurrences are linked to tumor characteristics and to delays between diagnosis and transplantation.

METHODS

We retrospectively analyzed data from French kidney-transplanted patients with medical histories of pretransplant renal cancer, focusing on the most common histological subtypes: clear cell and papillary cancers. Characteristics of the tumors, patients, and kidney transplantations were documented, and posttransplant patient survival was analyzed.

RESULTS

Of 143 patients, 13 experienced cancer recurrence after kidney transplantation. The mean delay in recurrence was 3 ± 2.3 years posttransplantation, and the cumulative incidences of recurrence were 7.7% at 5 years and 14.9% at 10 years. The risk of recurrence was higher in patients with clear cell RCC (13% vs 0%, P = 0.015). There was no correlation between posttransplant recurrence and the interval before transplantation. Factors associated with a higher risk of cancer recurrence were histological clear cell RCC (P = 0.025), tumor stage pT2 (P = 0.002), and Fuhrman grade IV (P < 0.001). Recurrences were associated with a high mortality rate; 76.9% of patients with recurrences had died by the end of the follow-up period.

CONCLUSIONS

Recurrences of clear cell RCC are not uncommon after kidney transplantation and are associated with very poor prognoses. These results should be considered before listing patients with a history of renal cancer for transplantation.

Clear cell papillary renal cell carcinoma: A case report and review of the literature

Clear cell papillary renal cell carcinoma (ccpRCC) was recently established as a distinct type of epithelial neoplasm by the International Society of Urological Pathology Vancouver Classification of Renal Neoplasia. Here, we report a case of partial nephrectomy for a ccpRCC detected during the routine follow-up of a previously treated liposarcoma in a 70-year-old male patient. The patient was referred to the urology department for a right-sided renal mass (size: 2 cm) detected during routine annual imaging follow-up for a malignant right inguinal fibrous histocytoma and liposarcoma that had been diagnosed 6 and 4 years earlier, respectively, and treated with surgery and adjuvant radiation therapy. Following partial nephrectomy, the renal mass was pathologically diagnosed as ccpRCC, and immunohistochemistry revealed carbonic anhydrase 9 (CA9) expression. No recurrences or metastases were detected on follow-up imaging for 6 months. This is the first report of partial nephrectomy for incidentally discovered CA9-positive ccpRCC.

Effect of the Need for Preoperative Dialysis on Perioperative Outcomes on Patients Undergoing Laparoscopic Nephrectomy: An Analysis of the National Surgical Quality Improvement Program Database

OBJECTIVE

To investigate whether patients requiring dialysis are a higher risk surgical population and would experience more perioperative adverse events even when undergoing a perceived less invasive operation as a laparoscopic radical nephrectomy (LRN). LRN is generally a well-tolerated surgical procedure with minimal morbidity and mortality. Prior to transplantation, dialysis patients will often have to undergo a LRN to remove a native kidney with a suspicious mass.

MATERIALS AND METHODS

Patients in the American College of Surgeons National Surgical Quality Improvement Program who underwent a LRN between 2011 and 2016 were included. Patients were stratified by the need for preoperative dialysis 2 weeks prior to surgery, and perioperative outcomes were compared. A multivariable logistic regression analysis was performed to test the association between the need for preoperative dialysis and perioperative risk.

RESULTS

There were 8315 patients included in this analysis of which 445 (5.4%) patients required preoperative dialysis. Patients who required preoperative dialysis had more minor (P <.0001) and major (P = .0025) complications, a higher rate of return to the operating room (P = .002), and a longer length of stay (P <.0001) than those patients not requiring preoperative dialysis. In a multivariate analysis, the need for preoperative dialysis was independently associated with adverse perioperative outcomes (OR= 1.45, CI = 1.08-1.95, P = .015).

CONCLUSION

Patients requiring preoperative dialysis were more likely to experience a perioperative complication and have a longer length of stay. For LRNs performed prior to transplantation, further risk stratification is needed, and treatment sequencing may need to be reconsidered.

Acquired cystic disease-associated renal cell carcinoma is the most common subtype in long-term dialyzed patients: Central pathology results according to the 2016 WHO classification in a multi-institutional study

New pathological subtypes of renal cell carcinoma (RCC) were designated in the 2016 World Health Organization (WHO) classification corresponding to the features commonly seen in patients with end-stage renal disease (ESRD). To determine the clinicopathological findings of new subtypes, we reanalyzed all sections from 315 kidneys in 291 ESRD patients bearing RCC tumors surgically resected in three Japanese institutes by the central pathologist. Clear cell RCC was diagnosed in 144 kidneys (45.7%), acquired cystic disease (ACD)-associated RCC in 100 (31.7%), papillary RCC in 41 (13.0%), and other minor subtypes in 30 (9.52%). Multivariate analysis showed that longer duration of dialysis, young age, and male sex were independent prognostic clinical factors for the occurrence of ACD-associated RCC. ACD-associated RCC included more WHO/International Society of Urologic Pathology (ISUP) grade 3/4 cases compared to other RCCs. In contrast, other unfavorable findings were less frequent in ACD-associated RCC, including the presence of a sarcomatoid component, lymphovascular invasion, and necrosis. In conclusion, ACD-associated RCC is a common histology in Japanese patients with ESRD. In addition, ACD-associated RCC showed more cases with a higher WHO/ISUP grade, but fewer cases with other unfavorable pathological features, suggesting a favorable prognosis of ACD-associated RCC.

Peritoneal Dialysis and Retroperitoneal Laparoscopic Radical Nephrectomy: A Favorable Experience With a Patient Complicated by Renal Cell Carcinoma

Peritoneal dialysis (PD) is an accepted modality for managing end-stage kidney disease. We herein report a 75-year-old female patient on chronic PD who was complicated by renal cell carcinoma. She was successfully treated with retroperitoneal laparoscopic radical nephrectomy followed by a prompt resumption of the procedure. Various surgeries disturbing the abdominal wall integrity often disrupt the regular PD schedule, and using minimally invasive approaches is therefore an attractive therapeutic option. Our experience emphasizes the feasibility and safety of a retroperitoneal approach–based laparoscopic technique based on several empirical examples. However, systemic studies on this topic are obviously lacking, so we strongly recommend the accumulation of more cases similar to our own. Several surgical concerns that need to be dealt with among PD patients are also discussed.

Mucin-Poor Mucinous Tubular and Spindle Cell Carcinoma of the Kidney Presented with Multiple Metastases Two Years after Nephrectomy: An Atypical Behaviour of a Rare, Indolent Tumour

Background

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare type of renal cell carcinoma, whose clinical behaviour and metastatic potential have not been fully elucidated to date. There are only a few metastatic cases in the literature, which all either featured sarcomatoid differentiation or were synchronously metastasised at diagnosis.

Case Presentation

We report a case of a 49-year-old male with end-stage kidney disease on dialysis, presenting with multiple osseous metastases of a mucin-poor variant of MTSCC of the kidney, without sarcomatoid differentiation, two years after bilateral nephrectomy for papillary renal cell carcinoma (RCC) at a curable stage. After retrospectively reexamining the initial nephrectomy specimens, the tumour of the right kidney was also diagnosed as a mucin-poor variant of MTSCC, while the tumour of the left kidney was confirmed as a papillary RCC.

Conclusions

It is proposed that MTSCC can be associated with end-stage renal disease and that particularly the mucin-poor variant is easily confused with papillary renal cell carcinoma, as happened in this case. Although it is considered as a relatively indolent malign entity, it can metastasise even years after successful primary surgical treatment. This implies, besides accurate diagnosis, that MTSCC patients should be monitored closely in the follow-up period.

Acquired Cystic Disease-Associated Renal Cell Carcinoma: Review of Pathogenesis, Morphology, Ancillary Tests, and Clinical Features

Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a recently described subtype of RCC found in individuals with ACD of the kidney. Because of underrecognition, information regarding this lesion is sparse but continues to accumulate with each new report. Herein, a thorough literature review amassing the current understanding of this unique neoplasm is presented. Discussion focuses on clinical features, pathogenesis, disease outcome, and relation to the duration of dialysis. The macroscopic and characteristic microscopic features are described with illustrations. Compared with previous opinion, compiled immunohistochemical data may now allow for recognition of a unique immunophenotypic pattern of ACD-RCC. Distinction of ACD-RCC from clear cell and papillary RCCs based on molecular genetic information is deliberated, including a summary of the most frequently detected cytogenetic abnormalities. The key morphologic and immunophenotypic patterns used to distinguish this entity from a comprehensive differential diagnosis are provided.

Morphologic, Molecular, and Taxonomic Evolution of Renal Cell Carcinoma: A Conceptual Perspective With Emphasis on Updates to the 2016 World Health Organization Classification

Molecular and morphologic interrogation has driven a much-needed reexamination of renal cell carcinoma (RCC). Indeed, the recently released 2016 World Health Organization classification now recognizes 12 distinct RCC subtypes, as well as several other emerging/provisional RCC entities. From a clinical perspective, accurate RCC classification may have important implications for patients and their families, including prognostic risk stratification, targeted therapeutics selection, and identification for genetic testing. In this review, we provide a conceptual framework for approaching RCC diagnosis and classification by categorizing RCCs as tumors with clear cytoplasm, papillary architecture, and eosinophilic (oncocytic) cytoplasm. The currently recognized 2016 World Health Organization classification for RCC subtypes is briefly discussed, including new diagnostic entities (clear cell papillary RCC, hereditary leiomyomatosis and RCC-associated RCC, succinate dehydrogenase-deficient RCC, tubulocystic RCC, and acquired cystic disease-associated RCC) and areas of evolving RCC classification, such as transcription elongation factor B subunit 1 (TCEB1)-mutated RCC/RCC with angioleiomyoma-like stroma/RCC with leiomyomatous stroma, RCC associated with anaplastic lymphoma receptor tyrosine kinase (ALK) gene rearrangement, thyroidlike follicular RCC, and RCC in neuroblastoma survivors. For each RCC subtype, relevant clinical, molecular, gross, and microscopic findings are reviewed, and ancillary studies helpful for its differential diagnosis are presented, providing a practical approach to modern RCC classification.

Surgical and Oncologic Outcomes of Laparoscopic Radical Nephrectomy for Non-Metastatic Renal Cancer in Long-Term Dialysis Patients

This study aimed to compare the outcomes of laparoscopic radical nephrectomy (LRN) between patients undergoing dialysis for ≤240 and >240 months. Data from all dialysis patients with non-metastatic renal cell carcinoma (RCC) treated with LRN between 2008 and 2015 in our hospital were evaluated retrospectively. Patients were divided into two groups, shorter- and longer-term dialysis patients, according to the preoperative duration of dialysis (≤240 vs. >240 months). Of 174 patients, 58 (33.3%) were on longer-term dialysis. Perioperative minor complications were significantly more frequent in the longer-term dialysis patients (P = 0.03). There was no significant difference between the two groups in other perioperative outcomes. Patients on longer-term dialysis more frequently had pathologically advanced RCC (P = 0.009) with poorer prognosis (P = 0.005). LRN for RCC in longer-term dialysis patients appears to be safe and feasible; however, careful follow-up is needed because these patients tend to have poorer prognosis.

Combination of mTOR and MAPK Inhibitors-A Potential Way to Treat Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by a unique biology, with a long history of poor response to conventional cancer treatments. In the past few years, there have been significant advancements to understand the biology of RCC. This has led to the introduction of novel targeted therapies in the management of patients with metastatic disease. Patients treated with targeted therapies for RCC had shown positive impact on overall survival, however, no cure is possible and patients need to undergo treatment for long periods of time, which raises challenges to manage the associated adverse events. Moreover, many patients may not respond to it and even response may not last long enough in the responders. Many inhibitors of the Mammalian target of Rapamycin (mTOR) signaling pathway are currently being used in treatment of advanced RCC. Studies showed that inhibitions of mTOR pathways induce Mitogen-Activated Protein Kinase (MAPK) escape cell death and cells become resistant to mTOR inhibitors. Because of this, there is a need to inhibit both pathways with their inhibitors comparatively for a better outcome and treatment of patients with RCC.

Feasibility, efficacy and safety of tyrosine kinase inhibitor treatment in hemodialyzed patients with renal cell cancer: 10 years of experience

AIMS

Sine efficiency of tyrosine kinase inhibitor (TKI) therapy in dialyzed patients is still unclear we aim to analyze the outcome of treatment in such cohort.

PATIENTS & METHODS

We analyzed treatment outcomes of patients with clear cell renal cell carcinoma (ccRCC) with special focus on those who were also treated with hemodialysis and described treatment safety and progression-free survival of eight patients treated with TKIs and hemodialysis.

DISCUSSION & CONCLUSION

Our report supports statement that TKI treatment of dialyzed patients is safe and effective. ccRCC increases risk of developing renal insufficiency as well as end-stage renal disease that require dialysis. Introduction of multitargeted receptor kinase inhibitors (TKIs), including sunitinib, sorafenib and pazopanib significantly expanded life time expectancy of metastatic renal clear cell carcinoma. The advance also applies to patients with ccRCC and end-stage renal disease who undergo dialyses.

Molecular genetics and immunohistochemistry characterization of uncommon and recently described renal cell carcinomas

Renal cell carcinoma (RCC) compromises multiple types and has been emerging dramatically over the recent several decades. Advances and consensus have been achieved targeting common RCCs, such as clear cell carcinoma, papillary RCC and chromophobe RCC. Nevertheless, little is known on the characteristics of several newly-identified RCCs, including clear cell (tubulo) papillary RCC, Xp11 translocation RCC, t(6;11) RCC, succinate dehydrogenase (SDH)-deficient RCC, acquired cystic disease-associated RCC, hereditary leiomyomatosis RCC syndrome-associated RCC, ALK translocation RCC, thyroid-like follicular RCC, tubulocystic RCC and hybrid oncocytic/chromophobe tumors (HOCT). In current review, we will collect available literature of these newly-described RCCs, analyze their clinical pathologic characteristics, discuss their morphologic and immunohistologic features, and finally summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of RCCs, and eventually promote clinical management strategies.

Use of mammalian target of rapamycin inhibitors after failure of tyrosine kinase inhibitors in patients with metastatic renal cell carcinoma undergoing hemodialysis: A single-center experience with four cases

We retrospectively identified patients with end-stage renal disease undergoing hemodialysis treated with the mammalian target of rapamycin inhibitors as a second- and/or third-line targeted therapy after treatment failure with the tyrosine kinase inhibitors for metastatic renal cell carcinoma. Patient medical records were reviewed to evaluate the response to therapies and treatment-related toxicities. Four patients were identified. All patients had undergone nephrectomy, and one had received immunotherapy before targeted therapy. Two patients had clear cell histology, and the other two had papillary histology. All patients were classified into the intermediate risk group according to the Memorial Sloan-Kettering Cancer Center risk model. All patients were treated with everolimus as a second- or third-line therapy, and two patients were treated with temsirolimus as a second- or third-line therapy after treatment failure with sorafenib or sunitinib. The median duration of everolimus therapy was 6.7 months, whereas that of temsirolimus was 9.5 months. All patients had stable disease as the best response during each period of therapy. There were no severe adverse events. The use of mammalian target of rapamycin inhibitors in patients who previously failed to respond to tyrosine kinase inhibitors appears to be feasible in patients with end-stage renal disease requiring hemodialysis.

Mucinous tubular and spindle cell renal cell carcinoma: a review of clinicopathologic aspects

Mucinous tubular and spindle cell renal cell carcinoma is a rare, recently described variant of renal cell carcinoma characterized by an admixture of cuboidal cells in tubules and sheets of spindle cells, and variable amounts of mucinous stroma. It has been recognized as a distinct entity in the 2004 World Health Organization tumor classification. Since then, several dozen of these tumor have been reported with additional complementary morphologic characteristics, immunohistochemical profile, and molecular genetic features that have further clarified its clinicopathologic aspects. Although originally considered as a low grade renal cell carcinoma on the basis of its bland appearing nuclear features and indolent clinical course, mucinous tubular and spindle cell renal cell carcinoma has currently been proven to be a tumor that has a histological spectrum ranging from low to high grade that includes sarcomatoid differentiation. In this review, we present a detailed summary of the current knowledge regarding the clinicopathologic, immunohistochemical, molecular genetic, and prognostic characteristics, as well as differential diagnoses of mucinous tubular and spindle cell renal cell carcinoma.

Pathology, therapy and prognosis of papillary renal carcinoma

Papillary renal cell carcinoma (pRCC) accounts for approximately 10% of renal parenchymal tumors. There are two pRCC subtypes reported in several studies, but at present, there is limited molecular evidence to validate this pRCC subtyping in the daily routine. The utility of subtyping pRCC is based on reports describing that pRCC subtype is an independent predictor of outcome, with type 1 tumors showing significantly better survival than type 2 tumors. In this article, we summarize the relevant knowledge on pRCC regarding tumor features: clinical presentation, histopathology, electron microscopy, immunohistochemistry, cytogenetics, genetic/molecular and prognosis. We present an overview of the currently available pRCC treatment options and some of the new promising agents.

Efficacy and safety of sorafenib for treatment of Japanese metastatic renal cell carcinoma patients undergoing hemodialysis

BACKGROUND

Little information has been published on the use of tyrosine kinase inhibitors for treatment of patients undergoing hemodialysis (HD). We investigated the efficacy and safety of sorafenib for metastatic renal cell carcinoma (mRCC) patients undergoing HD.

METHODS

Twenty patients undergoing HD were treated with sorafenib as first-line therapy for mRCC at our hospital between April 2008 and August 2014. Patient medical records were retrospectively reviewed to evaluate the response to sorafenib and treatment-related toxicity.

RESULTS

Fifteen and 5 patients were classified in the intermediate and poor risk groups, respectively, of the Memorial Sloan-Kettering Cancer Center risk model. Eighteen patients had 3 or more metastatic lesions, and 7 patients had metastases in 2 or more organs. Of 16 patients who had previously undergone nephrectomy, 8 were pathologically diagnosed with non-clear-cell carcinoma. The median duration of sorafenib therapy was 4.7 months. Sorafenib was discontinued owing to progressing disease for 15 patients and because of serious adverse events (AE) (≥grade 3) for 4 patients, i.e. subarachnoid hemorrhage, cerebral hemorrhage, sepsis, and syncope for 1 patient each. Median time to progression was 6.3 months, and median overall survival was 14.2 months.

CONCLUSIONS

In this study, many patients had unfavorable clinical features, for example poor risk classification and metastases in multiple organs. Although sorafenib treatment of HD patients seems feasible, careful monitoring is needed because of the tendency for a high incidence of serious AE, even when a reduced dose is administered.

Renal cell carcinoma in patients with end-stage renal disease is associated with more favourable histological features and prognosis

OBJECTIVE

End-stage renal disease (ESRD) patients with acquired cystic kidney disease are at higher risk of developing renal cell carcinoma (RCC) than the general population. The aim of this study was to investigate the clinical and histopathological differences between ESRD patients and the general population with RCC.

MATERIALS AND METHODS

Data were retrospectively collected from all nephrectomies performed for localized RCC from 2000 to 2010. Age at nephrectomy, gender, race, symptoms, baseline Eastern Cooperative Oncology Group (ECOG) performance status, Charlson Comorbidity Index score and histological data were extracted. Independent-samples t test and Mann-Whitney test were used for quantitative data, while chi-squared (two-sided) and Fisher's exact tests were used for qualitative data.

RESULTS

This study included 627 patients: 73 with and 554 without ESRD. The majority of patients were Chinese. The male to female ratio of 2:1 was identical in both groups. Baseline ECOG performance status and Charlson Comorbidity score were higher in the ESRD group. RCC in ESRD patients was more frequently asymptomatic (56.2% vs 44.9%, p = 0.071), diagnosed earlier (53.6 ± 11.8 years vs 57.9 ± 12.2 years, p = 0.004) and of lower stage (p < 0.001). The ESRD cohort had a higher proportion of the papillary histological subtype (21.9% vs 9.7%, p < 0.001). Importantly, there was a trend towards more favourable outcomes in ESRD patients in terms of cancer-specific (p = 0.203) and relapse-free survival (p = 0.096).

CONCLUSION

This study suggests that RCC in ESRD patients is associated with more favourable clinical and histological features and oncological outcome compared with that in patients with normal renal function.

The evolving classification of renal cell neoplasia

The classification of renal cell neoplasia is morphologically based; however, this has evolved over the last 35 years with the incorporation of genetic characteristics into the diagnostic features of some tumors. The 2013 Vancouver classification recognized 17 morphotypes of renal parenchymal malignancy and two benign tumors. This classification included the newly established entities tubulocystic renal cell carcinoma (RCC)), acquired cystic disease-associated RCC, clear cell (tubulo) papillary RCC, microphthalmia transcription factor family translocation RCC and hereditary leiomyomatosis RCC syndrome-associated RCC. In addition to these newly described forms of RCC there are a number of novel tumors that are currently recognized as emerging entities. These are likely to be incorporated into subsequent classifications and include thyroid-like follicular RCC, succinate dehydrogenase B mutation-associated RCC, ALK translocation RCC, tuberous sclerosis complex-associated RCC, and RCC with (angio) leiomyomatous stroma.

Risk of chronic kidney disease after cancer nephrectomy

The incidence of early stage renal cell carcinoma (RCC) is increasing and observational studies have shown equivalent oncological outcomes of partial versus radical nephrectomy for stage I tumours. Population studies suggest that compared with radical nephrectomy, partial nephrectomy is associated with decreased mortality and a lower rate of postoperative decline in kidney function. However, rates of chronic kidney disease (CKD) in patients who have undergone nephrectomy might be higher than in the general population. The risks of new-onset or accelerated CKD and worsened survival after nephrectomy might be linked, as kidney insufficiency is a risk factor for cardiovascular disease and mortality. Nephron-sparing approaches have, therefore, been proposed as the standard of care for patients with type 1a tumours and as a viable option for those with type 1b tumours. However, prospective data on the incidence of de novo and accelerated CKD after cancer nephrectomy is lacking, and the only randomized trial to date was closed prematurely. Intrinsic abnormalities in non-neoplastic kidney parenchyma and comorbid conditions (including diabetes mellitus and hypertension) might increase the risks of CKD and RCC. More research is needed to better understand the risk of CKD post-nephrectomy, to develop and validate predictive scores for risk-stratification, and to optimize patient management.

Acquired cystic disease-associated renal cell carcinoma: further characterization of the morphologic and immunopathologic features

Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a subtype of renal cell carcinoma (RCC) with unique morphologic features found exclusively in the background of end-stage renal disease. We analyzed the clinicopathologic features and immumoreactive profiles of 12 cases of ACD-RCC to further characterize this recently recognized entity. Review of histologic slides was performed in conjunction with immunohistochemical staining directed to the contemporary diagnostic antibodies and the putative target therapy-related markers. Histologically, the tumors showed characteristic inter-or intracellular microlumens and eosinophilic tumor cells. Intratumoral hemosiderin deposition and degenerating foamy tumor cells were consistent findings which were not previously described. Immunohistochemically, all the tumors were positive for alpha-methylacyl-CoA-racemase, CD10, pan-cytokeratin, PTEN (phosphatase and tensin homolog deleted on chromosome 10) and c-met, while negative for carbonic anhydrase-9, CD57, CD68, c-kit, pax-2, platelet-derived growth factor receptor (PDGFR)-α or vascular endothelial growth factor receptor (VEGFR)-2. Heterogenous staining was found for CK7 and kidney-specific cadherin. Positive reaction to c-met suggests its utility as a plausible therapeutic target in ACD-RCC. Thus, we present the unique morphologic and immunopathologic features of ACD-RCC, which may be helpful in both diagnostic and therapeutic aspects.

Cystic renal neoplasms and renal neoplasms associated with cystic renal diseases in adults: cross-sectional imaging findings

Cystic renal neoplasms in adults are a heterogeneous group of tumors with characteristic histogenesis, pathological findings, and variable biological profiles. They include disparate entities that are either biologically benign (lymphangioma, cystic nephroma, and mixed epithelial and stromal tumor) or malignant (cystic renal cell carcinoma, multilocular cystic renal cell carcinoma, and primary renal synovial sarcoma). Renal cystic diseases are characterized by cystic changes of the kidneys due to hereditary, developmental, or acquired etiology. Cystic renal diseases such as acquired cystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis are associated with the development of a wide spectrum of benign and malignant renal neoplasms. Most cystic renal tumors and cystic disease-associated renal neoplasms show characteristic cross-sectional imaging findings that permit accurate diagnosis. In addition, cross-sectional imaging is pivotal in the follow-up and surveillance of adult cystic tumors of the kidney.

The epidemiology and risk factors for renal cancer

BACKGROUND

Renal cancer is a frequently occurring malignancy with over 270,000 new cases diagnosed and it being responsible for 110,000 deaths annually on a global basis. Incidence rates have gradually increased whilst mortality rates are starting to plateau.

OBJECTIVE

To review epidemiology and risk factors for renal cancer.

METHODS

The current data is based on a thorough review of available original and review articles on epidemiology and risk factors for renal cancer with a systemic literature search utilising Medline.

RESULTS

The prevalence of associated risk factors such as genetic susceptibility, smoking, hypertension and obesity are changing and could account for the changes in incidence whilst the role of diet and occupational exposure to carcinogens requires further investigation.

CONCLUSION

Despite the evidence of various associated risk factors, further work is required from well designed studies to gain a greater understanding of the etiology of renal cancer.

Malignant tumors in patients with end stage renal failure undergoing renal replacement therapy

In 1975 Matas and co-workers were the first in the world literature to show an increased risk of malignant tumor occurrence in the group of hemodialyzed patients and kidney transplant recipients. The report is an analysis of world literature from the last 35 years in reference to epidemiology as well as the profile of screening tests and diagnostic methods related to malignant tumors in the population with end stage renal disease, especially hemodialyzed patients.

Rare (<1%) histological subtypes of renal cell carcinoma: an update

Recent advances in genetics and pathology have allowed description of several new histological subtypes of renal cell carcinoma (RCC) as well as better characterization of other rare subtypes. We herein present a comprehensive review of taxonomy, epidemiology, pathology, imaging findings, and natural history of a wide spectrum of rare subtypes of RCCs that individually constitute <1% of all the RCCs.

Sex differences in the development of malignancies among end-stage renal disease patients: a nationwide population-based follow-up study in Taiwan

Increasing evidence indicates that end-stage renal disease (ESRD) is associated with the morbidity of cancer. However, whether different dialysis modality and sex effect modify the cancer risks in ESRD patients remains unclear. A total of 3,570 newly diagnosed ESRD patients and 14,280 controls matched for age, sex, index month, and index year were recruited from the National Health Insurance Research Database in Taiwan. The ESRD status was ascertained from the registry of catastrophic illness patients. The incidence of cancer was identified through cross-referencing with the National Cancer Registry System. The Cox proportional hazards model and the Kaplan–Meier method were used for analyses. A similar twofold increase in cancer risk was observed among ESRD patients undergoing hemodialysis (HD) or peritoneal dialysis (PD) after adjusting for other potential risk factors. Patients with the highest cancer risk, approximately fourfold increased risk, were those received renal transplants. Urothelial carcinoma (UC) had the highest incidence in HD and PD patients. However, renal cell carcinoma (RCC) had the highest incidence in the renal transplantation (RT) group. In addition, female patients undergoing RT or PD had a higher incidence of RCC and UC, respectively. Male patients under HD had both higher incidence of RCC and UC. In conclusion, different dialysis modality could modify the cancer risks in ESRD patients. We also found sex effect on genitourinary malignancy when they are under different dialysis modality.

De novo renal cell carcinoma of native kidneys in renal transplant recipients: a single-center experience

OBJECTIVES

Our study aimed to determine the incidence of de novo renal cell carcinoma in the native kidneys of patients transplanted at our center and to identify possible risk factors.

MATERIALS AND METHODS

We performed a retrospective, single-center cohort study, which included patients transplanted at the District Hospital in Poznan, Poland, during 1994-2011, among whom 836 were selected. Sixty-three patients with confirmed de novo cancer were found. Of those, 11 had renal cell carcinoma in the native kidney (1.3%) and 2 in the transplanted kidney (0.2%).

RESULTS

Mean follow-up was 10 ± 3.2 years. Mean age at renal cell carcinoma diagnosis was 52 ± 9.4 years, and mean time from transplant was 3 ± 2.6 years. A statistical analysis showed no significant differences in demographic or clinical characteristics between renal cell carcinoma and noncancer group, except for the prevalence of male sex and smoking in the cancer group (P < .05).

CONCLUSIONS

Renal cell carcinoma development in the native kidney seems to be an early event, frequently observed within 4 to 5 years after transplant. We believe that kidneys in renal transplant recipients should be routinely screened by ultrasound for early diagnosis.

End stage and chronic kidney disease: associations with renal cancer

There is a well known association between end stage renal disease and the development of kidney cancer in the native kidney of patients requiring renal replacement therapy. There is now emerging evidence that lesser degrees of renal insufficiency (chronic kidney disease, CKD) are also associated with an increased likelihood of cancer in general and kidney cancer in particular. Nephropathological changes are commonly observed in the non-tumor bearing portions of kidney resected at the time of partial and radical nephrectomy (RN). In addition, patients with renal cancer are more likely to have CKD at the time of diagnosis and treatment than the general population. The exact mechanism by which renal insufficiency transforms normal kidney cells into tumor cells is not known. Possible mechanisms include uremic immune inhibition or increased exposure to circulating toxins not adequately cleared by the kidneys. Surgeons managing kidney tumors must have an increased awareness of their patient's renal functional status as they plan their resection. Kidney sparing approaches, including partial nephrectomy (PN) or active surveillance in older and morbidly ill patients, can prevent CKD or delay the further decline in renal function which is well documented with RN. Despite emerging evidence that PN provides equivalent local tumor control to RN while at the same time preventing CKD, this operation remains under utilized in the United States and abroad. Increased awareness of the bi directional relationship between kidney function and kidney cancer is essential in the contemporary management of kidney cancer.