Prevalence Of Renal Cell Carcinoma Research Articles

Artificial Intelligence in Surgical Training for Kidney Cancer: A Systematic Review of the Literature.

The prevalence of renal cell carcinoma (RCC) is increasing due to advanced imaging techniques. Surgical resection is the standard treatment, involving complex radical and partial nephrectomy procedures that demand extensive training and planning. Furthermore, artificial intelligence (AI) can potentially aid the training process in the field of kidney cancer. This review explores how artificial intelligence (AI) can create a framework for kidney cancer surgery to address training difficulties. Following PRISMA 2020 criteria, an exhaustive search of PubMed and SCOPUS databases was conducted without any filters or restrictions. Inclusion criteria encompassed original English articles focusing on AI's role in kidney cancer surgical training. On the other hand, all non-original articles and articles published in any language other than English were excluded. Two independent reviewers assessed the articles, with a third party settling any disagreement. Study specifics, AI tools, methodologies, endpoints, and outcomes were extracted by the same authors. The Oxford Center for Evidence-Based Medicine's evidence levels were employed to assess the studies. Out of 468 identified records, 14 eligible studies were selected. Potential AI applications in kidney cancer surgical training include analyzing surgical workflow, annotating instruments, identifying tissues, and 3D reconstruction. AI is capable of appraising surgical skills, including the identification of procedural steps and instrument tracking. While AI and augmented reality (AR) enhance training, challenges persist in real-time tracking and registration. The utilization of AI-driven 3D reconstruction proves beneficial for intraoperative guidance and preoperative preparation. Artificial intelligence (AI) shows potential for advancing surgical training by providing unbiased evaluations, personalized feedback, and enhanced learning processes. Yet challenges such as consistent metric measurement, ethical concerns, and data privacy must be addressed. The integration of AI into kidney cancer surgical training offers solutions to training difficulties and a boost to surgical education. However, to fully harness its potential, additional studies are imperative.

Long-term outcome of renal cell carcinoma in patients with HIV who undergo surgery

BackgroundPeople living with HIV (PLWH) have a higher risk for cancer compared to the general population. The prevalence of renal cell carcinoma (RCC) in PLWH has gradually increased in recent years, but relevant data on outcomes after surgery are scarce. We thus evaluated long-term outcomes after surgery in RCC patients with and without HIV.MethodsThis retrospective study included 67 patients with RCC, both HIV positive or negative, who underwent surgical treatment in our hospital between January 2012 and January 2021. Demographic details, clinical data, and cancer status were collected. We set the day of surgery as the baseline. The co-primary end points in this time-to-event analysis were overall survival and progression-free survival. We used a multivariate Cox model to compare the prognosis of PLWH and HIV-negative patients and present Kaplan–Meier curves for the co-primary end points.ResultsOf 261 consecutive patients, 18 patients who forwent treatment before surgery, 133 cases with incomplete data, 16 patients classified as clinical stage IV, 11 PLWH patients did not received antiretroviral therapy and 16 patients with metastasis were excluded from the main analysis. Of the remaining 67 patients, 33 individuals had HIV and the other 34 did not. The median overall survival was 74.9 months (95% confidence interval [CI] = 64.6 to 85.2) in PLWH and 96.4 months (95% CI = 90.0 to 102.9) in the HIV-negative group. Progression-free survival was 66.4 months (95% CI = 53.5 to 79.3) and 90.6 months (95% CI = 81.1 to 100.1), respectively. RCC patients with HIV who underwent surgery had a shorter survival time (hazard ratio [HR] = 2.8, 95% CI = 1.1 to 7.0, p = 0.016) and an increased incidence of tumor progression (HR = 2.7, 95% CI = 1.1 to 6.8, p = 0.028). Univariate and multivariate Cox regression analyses showed that a lower ratio of CD4+ T cells to CD8+ T cells (adjusted odds ratio = 0.092, 95% CI = 0.01 to 0.70, p = 0.022) was associated with worse survival among PLWH.ConclusionIn this retrospective analysis of RCC patients who underwent surgery, PLWH had worse overall survival and shorter progression-free survival compared to HIV-negative cases.

Precision medicine and renal cell carcinoma: current situation and the future

The prevalence of renal cell carcinoma is increasing in recent years. With the development of research, we know more about the mechanism and biological characteristics of renal cell carcinoma. Currently, the most used prognosis evaluation methods are clinical factors based prognostic prediction models. New drugs, typified by the checkpoint inhibitors, have achieved great success in the treatment of renal cell carcinoma, on the basis of traditional tyrosine kinase inhibitor. With recognition of more prognosis and treatment related biomarkers, directive role for the prognosis prediction and treatment options could be expected.

Prevalence of Renal Cell Carcinoma in Samples Sent to the Pathology Department of Kabul University of Medical Sciences and City Medical Laboratory

Background: Renal cell carcinoma (RCC) is the most common malignant tumor of the kidney. This tumor originates from the epithelial cells of the renal tubules and is located mainly in the cortical region of the kidney. It constitutes approximately 90% of all kidney malignancies and 2% of all cancers in adults. Objectives: The present study was conducted to determine the prevalence of RCC and its histological subtypes in samples sent to the Pathology Department of Kabul University of Medical Sciences and City Laboratory. Methods: This is a retrospective cohort study of 81 nephrectomy and partial nephrectomy samples registered in the laboratory of the Pathology Department of Kabul University of Medical Sciences and City Medical laboratory database from March 2016 to August 2020. Results: A total of 81 samples were included in this study. The mean and standard deviation (SD) age of the patients was 44.4 ± 20.5. Of 81 samples, 62 (76.6%) were malignant kidney tumors, 13 (16.0%) were inflammatory kidney disease, 4 (4.9%) were polycystic kidney disease, and 2 (2.5%) were benign kidney tumors. Among 62 cases of malignant kidney tumor, 53 (85.48%) were RCC. The high incidence of RCC was in the age group of 56 to 65 years with a mean of 52.2 years; 56.60% of RCC cases were male and 43.39% were female. Based on the histological studies, 75.47% were clear cell renal cell carcinoma (ccRCC) type, followed by 18.86% papillary renal cell carcinoma (PRCC), and 6% chromophobe renal cell carcinoma (ChRCC). Conclusions: Most common malignant tumor of the kidney in the samples included in this study was RCC in the age group of 56 to 65 years and it was more frequent among men compared to women, whereas the most common histological subtype was ccRCC. The findings are in concordance with international literature.

Cancer Prevalence and Risk Stratification in Adults Presenting With Hematuria: A Population-Based Cohort Study.

ObjectiveTo calculate the prevalence of renal cell carcinoma (RCC), upper urinary tract urothelial carcinoma (UT-UC), and lower urinary tract urothelial carcinoma (LT-UC) in patients with gross asymptomatic microhematuria (AMH) and symptomatic microhematuria (SMH).Patients and MethodsThis study was a population-based retrospective descriptive study. The study was approved by both the Mayo Clinic Institutional Review Board and the Olmsted Medical Center Institutional Review Board, and the population used was Olmsted County residents. A total of 4453 patients who presented with an initial episode of hematuria from January 1, 2000, through December 30, 2010, were included. Of the 4453 patients (median age, 58 years; interquartile range, 44.6-73.3 years), 1487 (33.4%) had gross hematuria, 2305 (51.8%) had AMH, and 661 (14.8%) had SMH.ResultsIn the 1487 patients with gross hematuria, the prevalence of RCC, UT-UC, and LT-UC was 1.3%, 0.8%, and 9.0%, respectively. In the 2305 patients with AMH, the prevalence of RCC, UT-UC, and LT-UC was 0.2%, 0.3%, and 1.6%, respectively. In the 661 patients with SMH, the prevalence of RCC, UT-UC, and LT-UC was 0.6%, 0.2%, and 0.3%, respectively. Age was the most relevant risk factor for any hematuria type.ConclusionThis unique cohort study reported that the prevalence of RCC or UC in patients with AMH and SMH was low, especially in the young cohort, and a large number of intense work-ups, such as cystoscopy and computed tomography urography, currently conducted could be omitted if stratified by hematuria type and age.

Modulation of Calcium Homeostasis May Be Associated with Susceptibility to Renal Cell Carcinoma in Diabetic Nephropathy Rats.

IntroductionClinical studies have indicated a relationship between diabetic nephropathy (DN) and the incidence and prevalence of renal cell carcinoma (RCC). However, the mechanism linking diabetic nephropathy and renal cell carcinoma has not yet to be identified.MethodsIn this study, a total of 42 male Sprague Dawley (SD) rats were randomly assigned to a DN group (n=35) and a control group (n=7). All animals in the DN group were unilaterally nephrectomized and treated with streptozotocin with the development of blood glucose levels >16.7mmol/L and dominant proteinuria and were compared to controls without such changes. Histopathologic alterations in the kidneys were examined by HE staining and Ki-67 immunohistochemistry. Differentially expressed genes were identified and validated by RNA-seq and PCR.ResultsAs the results, except for two rats that failed to develop the DN model and were excluded from the analysis, 33 rats in the DN group with overt signs of DN demonstrated significantly higher food and water intake, urine production, and urine protein and urinary protein/creatinine ratio than controls. Overall, 15.2% (n=5/33) of DN animals developed RCC while none tumors were observed in the control group (n=0/7). RNA-seq analysis in these animals indicated different TRPV5 gene expression and calcium pathway expression in DN animals with developing tumors, when compared with animals with no obvious tumors. In addition, DN animals diagnosed with RCC showed increased expression of GLUT2 and c-met, when compared to controls and DN animals without tumors.DiscussionIn conclusion, the disordered calcium metabolism, especially disturbed TRPV5 mediated Ca2+ signal, may have been related to the development of RCC in DN rats. Further studies related to the detailed mechanism are still needed.

The Harms of Hematuria Evaluation: Modeling the Risk-Benefit of Using Split Bolus Computerized Tomography Urography to Reduce Radiation Exposure in a Theoretical Cohort.

Computerized tomography urography is used to evaluate patients with gross or microscopic hematuria. Computerized tomography urography is a high radiation dose scan and, thus, it confers a higher risk of secondary malignancy. A computerized tomography urography split bolus protocol reduces radiation exposure but it may reduce sensitivity. In this study we used a theoretical cohort of patients with hematuria in which to model the risk of missing malignancies against the benefit of averting secondary malignancies. We calculated the prevalence of renal cell carcinoma and upper tract urothelial carcinoma in patients with hematuria by pooled analysis of cohort studies, which in conjunction with split bolus sensitivity allows for the estimation of missed malignancies. The number of prevented secondary malignancies was calculated from lifetime attributable risk estimates. Sensitivity analyses were run to determine the minimum sensitivity required for a net population benefit. Estimates of split bolus computerized tomography urography sensitivity ranged from 80% to 100% (mean 95.2%). At the low estimate of 80% sensitivity split bolus computerized tomography urography was beneficial in men and women with microscopic hematuria at ages less than 50 and less than 60 years, respectively. An increase in sensitivity to 90% improved the benefit 1 decade in each gender, representing 68.8% of patients with microscopic hematuria. The overall population of patients with microscopic hematuria benefited from split bolus computerized tomography urography at 91.1% sensitivity. However, in patients with gross hematuria the threshold for an overall population benefit was high at 98.4% sensitivity. Exposure to ionizing radiation risks causing secondary malignancy. These data indicate that split bolus computerized tomography urography may be performed safely in 70% of the population of patients with microscopic hematuria. However, it is not currently advisable in patients with gross hematuria or in other patients at high risk.

A cost-benefit analysis for sonographic screening for renal tumors.

665 Background: In the last 2 decades, the rates of metastatic Renal Cell Carcinoma (RCC) at diagnosis declined from 33% to 17%This fact is attributed to massive penetration of cross sectional imaging leading to a marked stage migration. The cost of targeted therapy for metastatic RCC patients is very high. These trends led us to hypothesize that screening for RCC with ultrasound may be cost effective. Objective: To assess the cost effectiveness of screening with ultrasound for renal tumors in the general population over 60 years of age. Methods: Using the Markov model, a mathematical framework was set up describing the course of disease with and without screening for RCC using abdominal ultrasonography. Quality Adjusted Life Year (QALY) and financial costs were the outputs of the model. Results: Average costs for the screening strategy was 137.4 U$ and for non-screening was 31.4 U$. Screening and non-screening strategy would add an average of 21.7396 and 21.7385 QALY, respectively. An increase of 0.001 QALY equates to Incremental Cost Effectiveness Ratio (ICER) of 86,4 U$ per QALY, Currently, the cost which is considered cost effective for 1 QALY point is approximately 27,548.21 U$. The two variables most influential on the model output were prevalence of RCC and US cost. Conclusions: To our knowledge, this is the sole cost benefit screening study performed for RCC in the targeted therapy era. Screening for renal tumors using abdominal ultrasonography at a cost of 35.81 U$ per exam is cost effective. Our findings are highly suggestive that early screening for RCC may be cost effective for preventing RCC metastatic disease and nevertheless will save lives.

Meta-analysis of the prevalence of renal cancer detected by abdominal ultrasonography.

The potential for an ultrasound-based screening programme for renal cell carcinoma (RCC) to improve survival through early detection has been the subject of much debate. The prevalence of ultrasound-detected asymptomatic RCC is an important first step to establishing whether a screening programme may be feasible. A systematic search of MEDLINE and Embase was performed up to March 2016 to identify studies reporting the prevalence of renal masses and RCC. Two populations of patients were chosen: asymptomatic individuals undergoing screening ultrasonography and patients undergoing ultrasonography for abdominal symptoms not related to RCC. A random-effects meta-analysis was performed. Study quality was evaluated using a validated eight-point checklist. Sixteen studies (413 551 patients) were included in the final analysis. The pooled prevalence of renal mass was 0·36 (95 per cent c.i. 0·23 to 0·52) per cent and the prevalence of histologically proven RCC was 0·10 (0·06 to 0·15) per cent. The prevalence of RCC was more than double in studies from Europe and North America than in those from Asia: 0·17 (0·09 to 0·27) versus 0·06 (0·03 to 0·09) per cent respectively. Data on 205 screen-detected RCCs showed that 84·4 per cent of tumours were stage T1-T2 N0, 13·7 per cent were T3-T4 N0, and only 2·0 per cent had positive nodes or metastases at diagnosis. At least one RCC would be detected per 1000 individuals screened. The majority of tumours identified are early stage (T1-T2).

Renal Cell Carcinoma : Are We Attacking a Different Tumor over the Past 10 Years ?

There is a noticeable increase in the presentation of different types of urological malignancies at a younger age of presentation, in our institution. The objective of our study was to investigate cases presented with renal cell carcinoma, managed in the past 10 years for any possible epidemiological and cancer characteristics changes. Retrospective data collection for cases managed by our institution in the time period (2002-2012) was done. We included patients with complete data and pathologically proven renal cell carcinoma at final diagnosis. Complete data could be retrieved for 334 patients. The mean age of cases was 43.5 years, with 279 (83%), 200 (60%) and 128 (38%) of patients younger than 60, 50 and 40 years respectively. Males and females involvement were 191 (57%) and 143 (43%) respectively. By histopathology, 200 (60%) of patients had clear cell (CC) RCC and 134 (40%) patients had non-clear cell type (papillary or chromophobe). The mean tumor size was 10.9 cm and partial nephrectomy was applied for 16% of all the cases, including 65% for cases with tumor size less than 4 cm. There is a marked increase in the prevalence of renal cell carcinoma in the past 10 years, among younger age group, with higher rate for involvement of female gender. RCC is tending to present with large tumor size and more prevalence of non-clear cell histopathology. The use of partial nephrectomy is accepted for patients presented with renal mass and can safely challenge larger sized tumors.

Letter to the Editor: Is Routine Screening Necessary for Renal Cell Carcinoma in End-Stage Renal Disease Patients?

To the editor: I read with great interest the original article by Lee et al. [1] published recently in your most valuable journal entitled Renal cell carcinoma in kidney transplant recipients and dialysis patients. It seems that the authors believe that routine screening is necessary for renal cell carcinoma (RCC) among patients with end-stage renal disease (ESRD). It is suggested that features such as increasing age, male gender, previous exposure to carcinogens, genetic predisposition, acquired cystic kidney disease (ACKD), and older age of the donor are common and important risk factors for RCC in kidney transplant patients [2,3]. The correlation of ACKD with the occurrence of RCC is stronger in dialysis patients than in kidney transplant recipients [1]. It is reported that the prevalence of RCC in the ESRD population is 3% to 4%, and that it is similar in dialyzed and transplanted patients, which corresponds to a rate 100 times that in the general population [4]. It is very interesting that clinical, pathological, and outcome features of RCCs arising in native kidneys of transplant patients seem to have many favorable properties when compared with those diagnosed in dialysis patients and patients from the general population. It is unclear whether this behavior is due to particular molecular pathways or to biases in relation to the mode of diagnosis, and this requires further research in the future [4,5]. When we focus on the prevalence and behaviors of RCC in ACKD patients, then we can understand why it is recommended in patients with ESRD that screening be performed only in patients with a long life expectancy and minimal major comorbidities with periodic ultrasound examination or computed tomography scans beginning during the third year on dialysis.

Are acquired cystic kidney disease and autosomal dominant polycystic kidney disease risk factors for renal cell carcinoma in kidney transplant patients?

The potent immunosuppressive agents predispose the kidney transplant patients to the development of several malignancies. Primary renal cell carcinoma (RCC) accounts 4.6% of all cancers among kidney transplant recipients, 90% in native kidneys and 10% in the allograft (1). Only 45 cases of allograft RCC have been reported by the Cincinnati Transplant Tumor Registry (2). Apart from a few isolated case reports, there have been only three largest case series including 3 of 1250, 5 of 1073 and 8 of 2050 RTRs had RCC (3-5). Between 1984 and 2008, we diagnosed five RCC among 5532 kidney transplants (6). Lee et al. (7) showed that the prevalence of patients with RCC after renal transplantation was 0.8%. In a study by Cheung et al. (8), the prevalence of native kidney RCC after renal transplantation was 1.3%. Several risk factors have been associated with RCC in kidney transplant patients include increasing age, male gender, previous exposure to carcinogens, genetic predisposition, acquired cystic kidney disease (ACKD) and older age of donor (1,9). Older age and male gender were risk factors for development of RCC in our patients.(6) Lee et al. (7) examined acquired cystic kidney disease (ACKD) development as a risk factor of RCC in the both groups. It is of interest of that ACKD was more likely to be occurred in the dialysis patients than the kidney transplant recipient. In addition ACKD occurrence was strongly correlated to the development of RCC in dialysis patients when compared to the kidney transplant recipient (7). This finding means that the incidence of ACKD seems to be lower in kidney transplant patients than in dialysis individuals. Schwarz et al. (9) reported a relatively high prevalence of RCC in kidney transplant patients with ACKD. Therefore, they concluded that ACKD was a risk factor for RCC among kidney transplant recipients and screening such as ultrasound should be performed for RCC in such patients, which consistent with study of Heinz-Peer et al. (10) reported a high prevalence of RCC in patients undergoing kidney transplantation. In addition, Cheung et al. (8) showed a high prevalence of RCC in kidney transplant recipients with autosomal dominant polycystic kidney disease (ADPKD) (8), although the association of ADPKD with RCC is very rare (11). Therefore, they concluded that ADPKD was a risk factor for RCC among kidney transplant recipients and screening such as ultrasound should be performed for RCC in such patients (8), which consistent with study of Hajj et al. (12).They reported a high prevalence of RCC in patients with end stage kidney disease as well as patients undergoing kidney transplantation(12). However, the increased development of RCC associated with ADPKD compared to the general population is controversial (13,14). In our previous study, 5 of 5532 kidney transplants had RCC; none of them had ADPKD (6). Moreover, in a large retrospective study, we enrolled 164 of 3725 transplant patients had history of ADPKD, 73% male and 23% female (unpublished data). None of them had RCC, but post-transplant diabetes mellitus was occurred in 16.7% of all patients. One, five and ten renal allograft survivals were 87.0%, 78.4% and 70.6%, respectively. We concluded that graft outcome after short- and long-term follow-up was promising and ADPKD was not a risk factor for development of the post-transplant malignancy. Although, relation between kidney cystic disease and RCC after kidney transplantation is still a controversial subject and further studies are require to provide a better understanding of this important clinical issue, we recommend a strict follow-up with annually ultrasonography in a such patients. Prompt and early diagnosis is the obvious cornerstone for successful management of these patients.

Renal cell carcinoma (RCC) arising in native kidneys of dialyzed and transplant patients: are they different entities?

What's known on the subject? and What does the study add? Patients with end-stage renal disease (ESRD) have an increased risk of developing RCC in their native kidneys. The prevalence of RCC is 3-4% in cases of ESRD in dialyzed and/or transplanted patients, which corresponds to a rate 100-times higher than that in the general population. This is the first study, to our knowledge, comparing the characteristics of kidney cancer in the ESRD population according to their dialysis or transplantation status at the time of diagnosis. The differences in stage and survival we observed may be due to differences in surveillance strategies between transplanted and not transplanted patients, nevertheless, the differences in pathological subtypes suggest they could also be due to differences in the tumorigenesis process. • To compare clinical, pathological and outcome features of renal cell carcinomas (RCCs) arising in patients with chronic renal failure (CRF) with or without renal transplantation. • In all, 24 French University Departments of Urology and Kidney Transplantation participated in this retrospective study comparing RCCs arising in patients with CRF according to their dialysis or transplantation status at the time of diagnosis. • Information about age, sex, symptoms, duration of CRF, mode and duration of dialysis, renal transplantation, tumour staging and grading, histological subtype and outcome were recorded in a unique database. • Qualitative and quantitative variables were compared by using chi-square and Student statistical analysis. Survival was assessed by Kaplan-Meier and Cox methods. • Data on 303 RCC cases diagnosed between 1985 and 2009 were identified in 206 men (76.3%) and 64 women (23.7%). • Transplanted and not transplanted patients accounted for 213 (70.3%) and 90 cases (29.7%), respectively. • In transplant recipients, RCC was diagnosed at a younger age [mean (sd) 53 (11) vs 61 (14) years, P < 0.001), the mean tumour size was smaller [3.4 (2.3) vs 4.2 (3.1) cm, P= 0.02), pT1a stage (75 vs 60%, P= 0.009) and papillary histological subtype (44 vs 22%, P < 0.001) were more frequent than in their dialysis-only counterparts. • Nodal (1 vs 6%, P= 0.03) and distant metastases rates (0 vs 5%, P < 0.001) were significantly increased in patients who had not had a transplant. However, Fürhman grading, symptoms, tumour multifocality or bilaterality, presence of acquired cystic kidney disease, were not significantly different between the groups. • Estimated 5-year survival rates were 97% and 77% for transplanted and not transplanted patients, respectively (P < 0.001). In univariate analysis, presence of symptoms (P= 0.008), poor performance status (P= 0.04), large tumour size, advanced TNM stage (P < 0.001), high Führman grade (P= 0.005) and absence of transplantation (P < 0.001) were all adverse prognostic factors. In multivariate analysis, only T stage remained an independent predictor for cancer-related death (P < 0.001). • RCC arising in native kidneys of transplant patients seems to exhibit many favourable clinical, pathological and outcome features compared with those diagnosed in dialysis-only patients. Further research is needed to determine whether it is due to particular molecular pathways or to biases in relation to mode of diagnosis.

Impact of Accidental Discovery of Renal Cell Carcinoma at Time of Renal Transplantation on Patient or Graft Survival

Renal tumors are common in the pretransplant end-stage renal disease population. Their impact on transplant outcome has not been well addressed. This study is a retrospective follow-up observational study conducted in 258 renal transplant recipients. All patients had an ipsilateral native nephrectomy at the time of transplantation. We reviewed the histopathology of all native nephrectomies to gauge the prevalence of renal cell carcinoma (RCC) and to investigate the impact of accidental discovery of RCC on graft and patient outcome. RCC was found in 12 patients (4.7%): clear type in 9 patients, and chromophobe and combined clear and papillary type in 1 and 2 patients, respectively. There was no significant difference in human leukocyte antigen mismatch, primary immunosuppression, occurrence of rejection, graft function, and patient and graft survival between patients with or without RCC. RCC presented in the other native kidney in three patients (25%) posttransplantation and one of them developed metastasis 4 years after renal transplantation in the RCC group in comparison with eight patients in the control group (3.3%; P<0.001). The median follow-up period was 56 months for the RCC group and 65 months for the control group. We found that renal transplant outcome and patient survival were not adversely affected by the presence of accidently discovered RCC at the time of transplantation. These patients seem to be at significantly higher risk of the occurrence of RCC in the remaining native kidney. Further studies are warranted to confirm our results.

The Role of Microscopic Hematuria in the Evaluation of Urologic Malignancy in Renal Transplant Recipients

Urologic malignancy is a relatively uncommon but serious complication following kidney transplantation. The reported prevalence of renal cell carcinoma (RCC) of the native kidneys is 4.4% and of bladder malignancy is 2.6%. However, presently there are no universal guidelines for prospective screening of urologic malignancies after kidney transplantation. We routinely monitored all renal transplant recipients for microscopic hematuria and persistent hematuria (>3 separate occasions) results in imaging studies (ultrasound or computed tomography scan) of both native kidneys and the allograft. Cystoscopy is performed if imaging studies are negative. This retrospective study identified a total of 18 urologic malignancies among the study cohort, which consisted of 539 patients with an incidence of 3.3% (12 cases of RCC of native kidneys [10/12 had hematuria], and six cases of bladder and ureteral malignancies [6/6 had hematuria]). There were no significant differences between cyclosporine- and tacrolimus-based immunosuppression (IS). Among RCC recipients, two lost the allograft from chronic allograft nephropathy and one patient died unrelated to malignancy. Among patients with bladder and ureteral malignancies, two lost the graft possibly from IS reduction and one had BK virus nephropathy prior to diagnosis of bladder carcinoma. In conclusion, screening transplant recipients routinely for persistent microscopic hematuria may identify urologic malignancies in renal transplant recipients.

Renal Cell Carcinoma: Incidence and Cost Estimation in the Era of Targeted Therapy

To the Editor: We have read with great interest the article of Bosetti et al. about the estimates of the incidence and prevalence of renal cell carcinoma (RCC) in Italy1. The medical management of metastatic RCC has changed considerably over the past several years and this tumor represents the best example of the introduction of targeted therapy into clinical practice, surpassing the traditional and less efficacious traditional therapies such as cytokine and chemotherapy. Although the incidence data might have general significance, the interest of medical oncologists regarding RCC is based particularly on the numbers and types of patients that could benefit from a particular type of treatment. RCC has been the subject of increasing attention not only of physicians and producers but also payers because of the costs and rapid adoption of new agents and technologies2. Bosetti et al. define their approach as being based on epidemiological knowledge and reasonable assumptions and for this reason it is readily questionable and lacks clinical confirmation. Nevertheless, the data can be indirectly confirmed by the 2007 National Report of the Italian Drugs Agency (AIFA) on cancer drugs subject to surveillance3. To ensure the correct use of cancer drugs, AIFA requires completion of a web page for each patient receiving particular cancer drugs including the biological agents sunitinib and sorafenib. Considering that the number of patients estimated by Bosetti et al. in 2007 with a diagnosis of RCC is 7350 and that stage IV at diagnosis is reported as 22% of new diagnoses annually4, the number of patients with stage IV disease can be expected to be approximately 1617. This number corresponds to the number of patients who could receive treatment for advanced or metastatic disease. If the estimate of Bosetti et al. is correct, the number of patients registered at AIFA should be close to the calculated value. From 21 December 2006 to 30 September 2007, 662 and 797 patients were registered to receive treatment with sorafenib or sunitinib either because their disease had progressed after first-line treatment with interferon (IFN) or interleukin-2 (IL-2), or because they showed intolerance to these agents. To avoid patients receiving both target therapies, patients who had received treatment other than IFN or IL-2 (43.1% and 44.0% of those treated with sorafenib and sunitinib, respectively) were excluded. If 823 patients were registered in 9 months (91.4 patients per month), we can estimate the number of patients treated in 1 year to be 1097. The number of patients registered at AIFA accounts for only 67.8% of Bosetti’s estimate.What about the remaining 32.2%? Are these patients undertreated? The difference might be explained if we consider that not all patients with a diagnosis of metastatic disease are eligible for targeted therapy. AIFA formally includes only patients who receive second-line therapy with target agents and the AIFA register does not include patients enrolled in clinical trials. We may therefore conclude that the presented estimate can be regarded as sufficiently reliable and useful, considering the possibility to calculate the number of new patients per year eligible for active therapy. In the light of the increasing number of newmolecules registered in recent years for the treatment of RCC, these data are extremely important to estimate the increasing cost of cancer care, and consequently to choose the best therapeutic strategies, particularly in countries with a national health system.

Estimates of the Incidence and Prevalence of Renal Cell Carcinoma in Italy in 2002 and Projections for the Years 2007 and 2012

Data on kidney cancer incidence and prevalence are not available on a national and regional level. We provided estimates of the number of incident and prevalent cases of kidney and renal cell cancer in Italy overall and in various regions in 2002 and gave projections for the years 2007 and 2012. We derived annual numbers of incident cases combining mortality data provided by the World Health Organization and information on relative survival from kidney cancer and we subsequently derived 5-year prevalence by combining incidence with information on survival. We provided different projection estimates for the years 2007 and 2012 for incidence and prevalence, on the basis of various hypothetical scenarios, i.e., stable rates over time or steady falls by 1% per year. In 2002, there were about 8000 incident cases and 26,800 prevalent cases of kidney cancer in Italy. Of these, approximately 6800 and 22,750 were incident and prevalent cases of renal cell cancer, respectively. The most reliable estimate of incident kidney cancer cases in Italy over the period 2007-2012 is likely to range between 7000 and 9000. Of these, between 6000 and 8000 are renal cell cancer cases. The best estimate of prevalence of kidney cancer is between 20,000 and 34,000 cases and that of renal cell cancer between 17,000 and 29,000 cases. Incidence and prevalence of renal cell cancer are likely to remain approximately stable between 2002 and 2007. Increased diagnostic attention due to widespread use of echography and other diagnostic techniques may, however, lead to earlier detection of kidney neoplasms and consequently to an apparent increase in the incidence of renal cell cancer.

Cost of illness of renal cell carcinoma in Canada

15560 Background: Renal cell carcinoma (RCC) is the most common form of kidney cancer. RCC patients have limited treatment options and low survival rates, particularly for advanced-staged patients. Despite its importance, data on the economic burden of RCC are limited. Methods: A prevalence-based approach was used to estimate the aggregate annual societal cost burden of RCC in Canada. Key relationships represented in the model include the annual number of patients treated for RCC by age group and cancer stage; utilization of cancer treatments; unit costs; work-days missed, and wage rates. Results: The annual prevalence of RCC in Canada in 2005 was estimated to be 17,845 cases. The associated annual burden of RCC (Canadian $2005) was approximately $357 million ($19,981 per patient). Health-care costs and lost productivity accounted for 65.6% ($234 million) and 34.4% ($123 million) of the total, respectively. Reflecting its higher prevalence, the total cost associated with Stage II RCC accounted for the greatest share (67%) followed by Stage I, Stage III, and Stage IV RCC, at 19.8%, 11.6% and 1.6%, respectively. Conclusions: The economic burden of RCC in Canada is substantial at a cost of $357M which represents 2% of the total cost of illness of cancer in Canada ($16.64B, inflated to $2005). Interventions to reduce the prevalence of RCC have the potential to yield considerable economic benefits. [Table: see text]

Prevalence of renal cell carcinoma: A nation‐wide survey in Japan, 2002

To investigate the incidence of renal cell carcinoma, classified by sex, age group and region in Japan, following a 5-year interval after a previous survey performed in 1997. The survey was conducted between the beginning of January 2002 and the end of December 2002. A total of 1288 institutions in all 47 prefectures throughout Japan were requested to register cases. There were 7405 persons with renal cell carcinoma, consisting of 5063 males and 2342 females. Crude incidence rates were 8.2 and 3.6 per 100 000 population for men and women, respectively. Incidence rates in the Hokkaido region were highest followed by the Shikoku region. Despite incidence of renal cell carcinoma increasing to 7405 from the 6358 persons in 1997, statistical data reported by the Ministry of Health, Labor and Welfare indicate that rising age-adjusted death rate for this tumor reached a ceiling in the past decade. Early detection may have contributed to this current trend; however, further epidemiological research is required to fully elucidate this.

Renal Cell Carcinoma in Transplant Recipients with Acquired Cystic Kidney Disease

Acquired cystic kidney disease (ACKD) is a widely known renal cell carcinoma risk factor. An ultrasound screening of the native kidneys in all renal transplant patients of a renal outpatient clinic who received a transplant between 1970 and 1998 and presented between 1997 and 2003 (n = 916) was initiated prospectively. A total of 561 patients were screened. A total of 129 (23%) patients had ACKD; 46 (8.2%) patients had complex renal cysts (Bosniak classification, category IIF to III); and eight (1.5%) patients had newly diagnosed renal cell carcinoma, seven of which were associated with ACKD (category IV). One patient had renal cell carcinoma in the transplanted kidney. Together with 19 patients of the cohort with formerly diagnosed renal cell carcinoma (18 of them associated with ACKD), the prevalence of renal cell carcinoma among all patients was 4.8%; among the patients with ACKD, it was 19.4% (without ACKD 0.5%; P = 0.0001); and among the patients with complex renal cysts (category IIF to III), it was 54.4%. The patients with ACKD were older (54 +/- 13 versus 51 +/- 14 yr; P = 0.048), more often male (65 versus 54%; P = 0.03), more often had heart disease (44 versus 29%; P = 0.001), had larger kidneys (6.9 and 6.8 cm versus 6.0 and 5.9 cm; P < 0.001), and had more calcifications (29 versus 15%; P = 0.002). Renal cell carcinoma was bilateral in 26% of cases. Tumor histology was clear cell carcinoma in 58% and papillary carcinoma in 42% of cases; one patient had both. Only one patient had a lung metastasis, and no patient died. Renal cell carcinoma occurs often after renal transplantation and that especially patients with ACKD should routinely be screened. Because ACKD after renal transplantation seems to be less frequent (23%) than during dialysis treatment (30 to 90%), renal transplantation may inhibit renal cell carcinoma.