Morphologic evidence that analgesic-induced kidney pathology contributes to the progression of tumors of the renal pelvis

The Application of Lag Times in Cancer Pharmacoepidemiology: A Narrative Review

With the increasing utilization of medications worldwide, coupled with the increasing availability of long-term data, there is a growing opportunity and need for robust studies evaluating drug-cancer associations. One methodology of importance in such studies is the application of lag times. In this review, we discuss the main reasons for using lag times. Namely, we discuss the typically long latency period of cancer concerning both tumor promoter and initiator effects and outline why cancer latency is a key consideration when choosing a lag time. We also discuss how the use of lag times can help reduce protopathic and detection bias. Finally, we present practical advice for implementing lag periods. In general, we recommend that researchers consider the information that generated the hypothesis as well as clinical and biological knowledge to inform lag period selection. In addition, given that latency periods are usually unknown, we also advocate that researchers examine multiple lag periods in sensitivity analyses as well as duration analyses and flexible modeling approaches.

Rare squamous cell carcinoma of the kidney with concurrent xanthogranulomatous pyelonephritis: A case report and review of the literature

Case presentation

In the current study, we report a 69-year-old female patient who was initially diagnosed with xanthogranulomatous pyelonephritis (XGPN) with nephrolithiasis and a peri-renal abscess. She presented to our department with right flank pain. Physical examination revealed right costovertebral angle knocking pain and computed tomography revealed dilated calyces and one staghorn stone over right kidney, with multiple abscess accumulations over the right peri-renal region. Right radical nephrectomy was performed using a transperitoneal flank approach, and pathology revealed squamous cell carcinoma (SCC) with concurrent XGPN. The patient was alive at 4 months post-operative follow-up. To the best of our knowledge, this is only the fifth case of renal SCC with concurrent XGPN reported in the English medical literature.

Conclusion

Renal SCC with coexisting XGPN is an extremely rare presentation and only four cases have been previously reported in the English medical literature. A positive diagnosis for this rare combination of diseases was established, based on pathological and immunohistochemical examinations after radical nephrectomy. Poor prognosis has been reported in such cases. Malignancies should be considered in patients with a long-standing history of urolithiasis.

Preintervention risk stratification of renal pelvic cancer and ureteral cancer should differ

Purpose

To identify different preintervention prognostic factors between renal pelvic cancer (RPc) and ureteral cancer (Uc) and to develop different preintervention risk stratifications for each cancer type.

Materials and Methods

A total of 1,768 patients with organ-confined upper urinary tract urothelial carcinoma (1,067 patients with RPc and 701 with Uc) who presented between 2004 and 2015 were selected from the Surveillance, Epidemiology, and End Results database. Clinicopathologic characteristics were compared between RPc and Uc. Univariable and multivariable Cox regression models were used to examine the prognostic ability of the clinicopathologic characteristics with respect to oncology outcomes.

Results

Age greater than 75 years was significantly associated with cancer-specific survival (CSS) in RPc patients but not in Uc patients. Tumor size had a significant influence on CSS in Uc patients but not in RPc patients; in contrast, age had an influence in RPc but not in Uc. Unlike CSS, age was significantly associated with overall survival (OS) in both RPc and Uc. Tumor size had an effect on OS in Uc patients but not in RPc patients.

Conclusions

The preintervention prognostic factors differed between RPc and Uc. Thus, we should develop separate preintervention risk stratification standards for RPc and Uc. Using these specific preintervention risk stratifications, we may be able to select the most appropriate surgical options for patients in the clinic.

Epidemiology of urothelial carcinoma

The epithelium lining is defined as the mucosal surfaces of the renal collecting tubules, calyces and pelvis, as well as the ureter, bladder and urethra. The term "urothelium" is used to refer to these surfaces. Upper tract urothelial carcinoma is a rare subset of urothelial cancers with a poor prognosis. Urinary bladder cancer is the most common malignancy involving the urinary system. Upper tract urothelial carcinoma is more common in men than in women, with a male-to-female ratio of 2:1. The incidence of urinary bladder cancer is also higher in men. Cigarette smoking and occupational exposure are the main upper tract urothelial carcinoma and urinary bladder cancer risk factors, while other factors are more specific to the carcinogenesis of upper tract urothelial carcinoma (i.e. Balkan endemic nephropathy, Chinese herb nephropathy). In Egypt until recent years, urinary bladder cancer was the most frequently diagnosed cancer due to Schistosoma haematobium. Substantial knowledge exists regarding the causes of upper tract urothelial carcinoma and urinary bladder cancer, and epidemiological studies have identified various chemical carcinogens that are believed to be responsible for most cases of urothelial carcinoma. In the era of precision medicine, genetic effects might play a direct role in the initiation and progression of urothelial carcinoma.

Prognostic Impact of Thrombospodin-2 (THBS2) Overexpression on Patients with Urothelial Carcinomas of Upper Urinary Tracts and Bladders

Purpose: Urothelial carcinoma (UC) is a type of tumor, especially of the urinary bladder, that affects people worldwide. Clarification of its detailed tumor biology and discovery of potential targets for developing treatment strategies are imperative because of frequent recurrences and poor prognosis of advanced UCs. By data mining a published dataset of UC of bladder (UCB) transcriptome (GSE31684) from Gene Expression Omnibus, National Center of Biotechnology Information (GEO, NCBI), we identified that THBS2 was the most significantly upregulated gene among those related to structural molecule activity (GO:0005198). Therefore, we evaluated the clinical significance and prognostic impact of thrombospondin-2 (THBS2) protein, A.K.A. TSP2, which encoded by THBS2 gene.

Materials and Methods: THBS2 immunostaining was performed in 340 UCs of upper urinary tract (UC-UUTs) and 295 UCBs; subsequently, both groups were dichotomized into high- and low-expression subgroups. Moreover, statistical analyses were performed to correlate the association between THBS2 expression and clinicopathological parameters with two survival indexes: disease-specific survival (DSS) and metastasis-free survival (MeFS).

Results: High THBS2 immunoexpression was significantly associated with advanced primary tumor status, nodal metastasis, and vascular invasion in both UC-UUT and UCB groups (all P ≤ .001). In addition, THBS2 overexpression was linked to adverse DSS and MeFS in univariate analyses and served as an independent prognosticator indicating poor outcomes in both groups in multivariate analyses.

Conclusion: THBS2 may play a crucial role in UC progression and may be a novel prognostic marker. Additional investigations to elucidate the molecular pathway are necessary for developing potential THBS2-targeted therapies for UCs.

Complement Component 1, s Subcomponent Overexpression is an Independent Poor Prognostic Indicator in Patients with Urothelial Carcinomas of the Upper Urinary Tract and Urinary Bladder

Purpose: Urothelial carcinoma of the urinary bladder and upper tract is prevalent. By subjecting a documented transcriptome data set of urothelial carcinoma of bladder (GSE31684) to data mining and focusing on genes linked to peptidase activity (GO:0008233), we recognized C1S as the most significantly upregulated gene related to an advanced tumor status and metastasis. We subsequently analyzed the association of both C1S mRNA and its encoded protein expression with the clinical and pathological significance.

Materials and Methods: We used real-time reverse transcription polymerase chain reaction to detect C1S transcription levels in 20 cases each of urothelial carcinoma of bladder and upper tract. An immunohistochemical stain was conducted to determine C1s protein expression levels in patients with urothelial carcinoma of upper tract (n = 340) and urinary bladder (n = 295). Furthermore, we examined the correlation of C1s expression with clinicopathological characteristics, disease-specific survival, and metastasis-free survival.

Results: C1S transcription levels were significantly high in patients with advanced-stage tumors of both groups (all P < .05). Immunohistochemical analysis revealed that C1s expression levels were significantly associated with adverse clinicopathological parameters in both groups of urothelial carcinoma (all P < .05). C1s overexpression predicted poor disease-specific and metastasis-free survival rates for both urothelial carcinoma groups in the univariate analysis, and it was also an independent prognostic factor in the multivariate analysis (all P < .05).

Conclusions: C1s may play a pivotal role in urothelial carcinoma progress and can represent a vital prognostic marker and a promising new therapeutic target in urothelial carcinoma.

Necdin Overexpression Predicts Poor Prognosis in Patients with Urothelial Carcinomas of the Upper Urinary Tract and Urinary Bladder

BACKGROUND AND AIMS

Oncogenesis is a multistep process, resulting from the accumulations of multiple mutations. Of these mutations, self-sufficiency in growth signals, i.e., disruption of cell growth regulation, is the first episode. Nonetheless, the genes associated with cell growth dysregulation have seldom been systematically evaluated in either urothelial carcinomas of upper urinary tract (UTUC) or urothelial carcinomas of urinary baldder (UBUC). By data mining a published transcriptomic dataset of UBUCs (GSE31684), we identified the NDN gene as one of the most significant of those associated with the regulation of cell growth and found this gene is associated with advanced tumor status and metastatic disease (GO:0001558). Accordingly, we analyzed NDN transcript and protein expression with their clinicopathological significance.

MATERIALS AND METHODS

We used real time RT-PCR to detect NDN transcript levels in 27 UTUCs and 27 UBUCs, respectively. Immunohistochemical study was performed to determine NDN protein (a.k.a. Necdin) expression evaluated by H-score method in 340 UTUCs and 295 UBUCs. NDN expression was further correlated with clinicopathological features and disease-specific survival (DSS) and metastasis-free survival (MeFS).

RESULTS

NDN transcriptional level was significantly higher in UCs of both sites with stepwise more advanced pT statuses. Through immunohistochemistry, we found NDN protein expression was significantly associated with adverse clinicopathological parameters, e.g., advanced pT status, nodal metastasis, high grade histological patterns, and frequent mitotses (all P<0.05). In univariate analysis, NDN overexpression not only predicted worse DSS and MeFS in both the UTUC and UBUC groups, it also served as an independent prognostic factor for DSS and MeFS in multivariate analysis (all P<0.05).

CONCLUSIONS

NDN may play an important role in tumor progression in UC and could serve as a prognostic biomarker and a potential novel therapeutic target in UC.

HAS3 underexpression as an indicator of poor prognosis in patients with urothelial carcinoma of the upper urinary tract and urinary bladder

Via data mining a published transcriptomic database of UBUC (GSE31684), we discovered hyaluronan synthase-3 (HAS3) as the most significant gene stepwise downregulated from early tumorigenesis to progression among those associated with hyaluronan synthase activity (GO:0050501). We consequently analyzed HAS3 protein expression and their association with clinicopathological factors and survival in our well-characterized cohort of urothelial carcinoma of upper urinary tract (UTUC) and urinary bladder (UBUC). HAS3 expression was assessed by immunohistochemistry and evaluated by using H score method in 295 UBUCs and 340 UTUCs, respectively. HAS3 protein expression statuses were further correlated with clinicopathological parameters and evaluated the prognostic significance for disease-specific survival (DSS) and metastasis-free survival (MeFS). HAS3 protein underexpression was significantly associated with advanced pT status, nodal metastasis, high histological grade, vascular invasion, and frequent mitoses in both groups of UCs. HAS3 underexpression not only predicted poorer DSS and MeFS with univariate analysis, but also indicated dismal DSS and MeFS in multivariate analysis. HAS3 underexpression is associated with advanced tumor stage and adverse pathological features, as well as implies inferior clinical outcomes for both groups of patients with UTUCs and UBUCs, suggesting its critical role in tumor progression in UCs and may serve as a prospective prognostic biomarker and a novel therapeutic target in UCs.

Genotoxicity of phenacetin in the kidney and liver of Sprague-Dawley gpt delta transgenic rats in 26-week and 52-week repeated-dose studies

Transgenic rat mutation assays can be used to assess genotoxic properties of chemicals in target organs for carcinogenicity. Mutations in transgenes are genetically neutral and accumulate during a treatment period; thus, assays are suitable for assessing the genotoxic risk of chemicals using a repeated-dose treatment paradigm. However, only a limited number of such studies have been conducted. To examine the utility of transgenic rat assays in repeated-dose studies, we fed male and female Sprague-Dawley gpt delta rats with a 0.5% phenacetin-containing diet for 26 and 52 weeks. A long-term feeding of phenacetin is known to induce renal cancer in rats. Phenacetin administration for 52 weeks in males significantly increased gpt (point mutations) mutant frequency (MF) in the kidney, the target organ of carcinogenesis. In the liver, the nontarget organ of carcinogenesis, gpt MFs were significantly elevated in phenacetin treatment groups of both genders during 26- and 52-week treatments. Furthermore, sensitive to P2 interference (Spi(-)deletions) MF increased in the liver of both genders following 52-week treatment. MFs were higher after treatment for 52 weeks than after treatment for 26 weeks. Frequencies of phenacetin-induced mutations were higher in the liver than in the kidney, suggesting that the intensity of genotoxicity does not necessarily correlate with the induction of tumor formation. Results from gpt delta rat assays of repeated-dose treatments are extremely useful to elucidate the relationship between gene mutations and carcinogenesis in the target organ induced by cancer-causing agents.

Continued increase in incidence of renal cell carcinoma, especially in young patients and high grade disease: United States 2001 to 2010

PURPOSE

More than 50,000 Americans were diagnosed with kidney and renal pelvis cancer in 2010. The National Program of Cancer Registries and SEER (Surveillance, Epidemiology and End Results) combined data include cancer incidences from the entire United States. Our study presents updated incidence data, evaluates trends and adds geographic distribution to the literature.

MATERIALS AND METHODS

We examined invasive, microscopically confirmed kidney and renal pelvis cancers diagnosed from 2001 to 2010 that met United States Cancer Statistics reporting criteria for each year, excluding cases diagnosed by autopsy or death certificate. Histology codes classified cases as renal cell carcinoma. Rates and trends were estimated using SEER∗Stat.

RESULTS

A total of 342,501 renal cell carcinoma cases were diagnosed. The renal cell carcinoma incidence rate increased from 10.6/100,000 individuals in 2001 to 12.4/100,000 in 2010 and increased with age until ages 70 to 74 years. The incidence rate in men was almost double that in women. The annual percent change was higher in women than in men, in those 20 to 24 years old and in grade III tumors.

CONCLUSIONS

The annual percent change incidence increased from 2001 to 2010. Asian/Pacific Islanders and 20 to 24-year-old individuals had the highest annual percent change. While some increase resulted from localized disease, the highest annual percent change was in grade III tumors, indicating more aggressive disease. Continued monitoring of trends and epidemiological study are warranted to determine risk factors.

Microsatellite instability and TARBP2 mutation study in upper urinary tract urothelial carcinoma

Microsatellite instability (MSI) contributes to the tumorigenesis of upper urinary tract urothelial carcinomas (UUT-UCs). In this study, we first used MLH1 and MSH2 immunohistochemistry to identify patients with loss of expression of either or both of these proteins in 132 UUT-UCs. We found a total loss of MSH2 expression in 4 patients. MSI was evaluated using 5 markers in these 4 cases. All of the tumors had high MSI (MSI-H) status. Trans-activation responsive RNA-binding protein 2, an integral component of DICER1-containing complex, was a putative target of DNA mismatch repair deficiency. Truncating mutation has been identified in gastrointestinal cancers with MSI. No previous study has evaluated the mutation status of this gene in MSI UUT-UCs. In this study, we analyze the mutation of TARBP2 in MSI-H UUT-UCs with reverse transcription polymerase chain reaction. No truncating mutations were identified in the MSI-H UUT-UCs.

Surgical management for upper urinary tract transitional cell carcinoma (UUT-TCC): a systematic review

Surgical management of upper urinary tract transitional cell carcinoma (UUT-TCC) has significantly changed over the past two decades. Data for several new surgical techniques, including nephron-sparing surgery (NSS), is emerging. The study systematically reviewed the literature comparing (randomised and observational studies) surgical and oncological outcomes for various surgical techniques MEDLINE, EMBASE, Cochrane Library, CINAHL, British Nursing Index, AMED, LILACS, Web of Science, Scopus, Biosis, TRIP, Biomed Central, Dissertation Abstracts, ISI proceedings, and PubMed were searched to identify suitable studies. Data were extracted from each identified paper independently by two reviewers (B.R. and B.S.) and cross checked by a senior member of the team. The data analysis was performed using the Cochrane software Review manager version 5. Comparable data from each study was combined in a meta-analysis where possible. For dichotomous data, odds ratios with 95% confidence intervals (CIs) were estimated based on the fixed-effects model and according to an intention-to-treat analysis. If the data available were deemed not suitable for a meta-analysis it was described in a narrative fashion. One randomised control trial (RCT) and 19 observational studies comparing open nephroureterectomy (ONU) and laparoscopic NU (LNU) were identified. The RCT reported the LNU group to have statistically significantly less blood loss (104 vs 430 mL, P < 0.001) and mean time to discharge (2.30 vs 3.65 days, P < 0.001) than the ONU group. At a median follow-up of 44 months, the overall 5-year cancer-specific survival (CSS; 89.9 vs 79.8%) and 5-year metastasis-free survival rates (77.4 vs 72.5%) for the ONU were better than for LNU, respectively, although not statistically significant. A meta-analysis of the observational studies favoured LNU group for lower urinary recurrence (P < 0.001) and distant metastasis. The meta-analyses for local recurrence for the two groups were comparable. One retrospective study comparing ONU with a percutaneous approach for grade 2 disease reported no significant differences in CSS rates (53.8 vs 53.3 months). Three retrospective studies compared NSS and radical NU, and reported no significant differences in overall CSS and recurrence-free survival between the two approaches. Five retrospective studies compared various techniques of en bloc excision of the lower ureter. No technique was reported to be better (operative and oncological) than any other. This review concludes that there is a paucity of good quality evidence for the various surgical approaches for UUT-TCC. The techniques have been assessed and reported in many retrospective single-centre studies favouring LNU for better perioperative outcomes and comparable oncological safety. The reported observational studies data is further supported by one RCT.

Environmental factors involved in carcinogenesis of urothelial cell carcinomas of the upper urinary tract

Primary cancers of the ureter and renal pelvis are rare tumours, > 90% of which are transitional cell carcinomas. Only approximately 5% of urothelial tumours arise in the upper urinary tract (UUT). Many environmental factors contribute to the development of these cancers. Some are similar to bladder cancer-associated factors (tobacco, occupational exposure), while others are more specific to carcinogenesis of the UUT (phenacetine, Balkan endemic nephropathy [BEN], Chinese herb nephropathy or association with Blackfoot disease [BFD]). This review discusses the environmental factors involved in UUT carcinoma. Tobacco and occupational exposure remain the principal exogenous risk factors for developing these tumours. Conversely, carcinogenesis of UUT tumours resulting from phenacetine consumption has almost disappeared. Although the incidence of BEN is also on the decline, roles for aristolochic acid and the consumption of Chinese herbs in the physiopathology and induction of this nephropathy, respectively, have proposed. In Taiwan, the association of this tumour type with BFD and arsenic exposure remains unclear to date. As some genetic polymorphisms are associated with an increased risk of cancer or faster disease progression, there is variability in interindividual susceptibility to the development of UUT carcinoma when exposed to the aforementioned risk factors Cytosolic sulfotransferases (SULTs) catalyse the detoxification of many environmental chemicals but also in the bioactivation of dietary and other mutagens. Polymorphism of the SULT gene, is thought to confer susceptibility to upper tract tumours.

Shared occupational risks for transitional cell cancer of the bladder and renal pelvis among men and women in Sweden

BACKGROUND

Unlike cancer of the bladder, cancer of the renal pelvis is not considered an occupational cancer and little is known about risks among women.

METHODS

Using the Swedish national census and cancer registry-linked data (1971-1989), we identified transitional cell cancers of the renal pelvis (N = 1,374) and bladder (N = 21,591). Correlation between cancer sites for the standardized incidence ratios (SIR) were determined using Pearson's coefficient of the log SIR. Relative risks of job exposure matrix variables were calculated using Poisson regression.

RESULTS

Both cancer sites were significantly elevated among women and men employed in the machine/electronics industry, sedentary work, and indoor work, and men in the metal industry. The highest proportion of the bladder (12%) and renal pelvis (14%) cancers occurred among men employed in shop and construction metal work. Risks by industry were more correlated among women (r = 0.49, P = 0.002) than men (r = 0.24, P = 0.04). Cancers of the renal pelvis were elevated in several occupational and industry groups for which there was no elevated bladder cancer risk.

CONCLUSION

Cancers of the renal pelvis and bladder share common occupational risk factors that may be more frequent among women. In addition, there may be some jobs that pose an increased risk specifically for cancer of the renal pelvis but not bladder.

Carcinoma of the renal pelvis and ureter

OBJECTIVE

To assess the occurrence of upper urinary tract urothelial tumors (UUTT) in Brazil.

MATERIALS AND METHODS

We performed a clinical and histopathologic study of 33 patients who were diagnosed with a malignant neoplasm in the renal pelvis or ureter in the period of 1994 to 2004, in a single institution.

RESULTS

Among the patients with upper urinary tract carcinoma, 70% were males and 30% females, with mean age of 65 +/- 16 years (ranging from 31 to 91 years). Nineteen patients presented renal pelvis tumor (58%), 9 ureteral tumor (27%) and 5 synchronic pelvic and ureteral tumors (15%). Renal pelvis tumors represented 2.8% of all the urothelial neoplasms, and 11.4% of all renal neoplasms treated in the same period. Ureteral tumors represented 1.6% of all the urothelial malignancies surgically managed in these 11 years. Tobacco smoking was the most common risk factor, and analgesic abuse was not reported by those patients. Most carcinomas were high-grade and muscle-invasive. Mean time to diagnosis was 7 months, being hematuria the most common symptom.

CONCLUSIONS

A high association was also found between UUTT and bladder urothelial carcinoma. UUTT were mostly seen in men in their seventies and related to a high overall and cancer-related mortality rate. The overall disease-specific survival was 40%, much lower than found in most of the reported series.

Phenacetin acts as a weak genotoxic compound preferentially in the kidney of DNA repair deficient Xpa mice

Chronic use of phenacetin-containing analgesics has been associated with the development of renal cancer. To establish genotoxicity as a possible cause for the carcinogenic effect of phenacetin, we exposed wild type and DNA repair deficient Xpa-/- and Xpa-/-/Trp53+/- mice (further referred as Xpa and Xpa/p53 mice, respectively), carrying a reporter lacZ gene, to 0.75% (w/w) phenacetin mixed in feed. Xpa mice completely lack the nucleotide excision repair pathway, and as such they are sensitive to some classes of genotoxic compounds. Phenacetin exposure induced a significant increase of lacZ mutations in the kidney of both Xpa and Xpa/p53 mice. A minor response was found in liver, whereas no lacZ mutation induction was observed in the spleen of these animals. Interestingly, the observed phenacetin-induced mutant frequencies were higher in male than those found in female mice. This gender difference is probably due to a difference in metabolic rate. Phenacetin-induced mutations mainly consisted of point mutations rather than deletions. The mutational spectra in the kidney of treated WT and Xpa mice were quite similar. Taken together, these results demonstrate that the human carcinogen phenacetin acts as a weak genotoxic agent in an in vivo mouse model system.

Carcinomes urothéliaux de la voie excrétrice supérieure

Transitional cell carcinomas of the upper urinary tract (UUT-TCCs) are rare: they account for approximately 5% of all urothelial carcinomas. 30% of patients with UUT-TCC have a history of bladder TCC, but fewer than 2% of patients with bladder TCC have UUT-TCC. Tumor microsatellite instability (MSI) is an indicator of the clonal expansion of neoplasms; it was first identified in tumors from patients with hereditary non-polyposis colorectal carcinoma (HNPCC). UUT-TCC occurs in 5% of patients with HNPCC. High-frequency microsatellite instability is present in almost 20% of cases of sporadic UUT-TCC. In cases of UUT-TCC with high-frequency MSI, hereditary cancer must be sought, especially if the patient is younger than 60 years or has a personal or family history of an HNPCC-related cancer: such patients should undergo DNA sequencing for the MSH2 gene germline mutation. Invasive UUT-TCC has a poor prognosis. 5-year survival is less than 50% for stage T2-T3 tumors and less than 10% for T4 or N+/M+ tumors. The main prognostic factors are age and tumor stage and grade. High-frequency MSI is a positive prognostic factor, especially in patients younger than 70 years with T2/T3/N0-M0 tumors.

Synchronous bilateral ureteral and renal pelvic carcinomas

BACKGROUND

Synchronous bilateral urothelial tumors of the upper urinary tract are very rare. The authors reported baseline and long-term follow-up data for all patients in western Sweden during a 28-year period.

METHODS

The authors performed a clinical and histopathologic study of all patients in western Sweden who were diagnosed with a malignant neoplasm in the renal pelvis or ureter between 1971 and 1998.

RESULTS

Of 936 patients, 15 (1.6%) had synchronous bilateral tumors. The incidence of such tumors decreased in each successive decade. Abuse of phenacetin-containing analgesics by patients also decreased during the study period, as did the incidence of renal papillary necrosis. The median age at diagnosis of bilateral tumors was 68 years, and 80% of the patients were male. Eleven patients had bilateral tumors of the renal pelvis, two had bilateral ureteral tumors, and two had tumors of the renal pelvis and contralateral ureter. Partial renal pelvic, ureteral, or kidney resection on at least one side was possible in eight patients, and four patients were left untreated on at least one side. Only three patients underwent bilateral nephroureterectomy. Twelve patients (80%) had bladder carcinoma diagnosed either before or after diagnosis of the upper tract tumors. The median survival period for the 11 patients who received surgery for their bilateral tumors was 84 months.

CONCLUSIONS

The decreasing incidence of synchronous bilateral upper tract tumors may be related to the prohibition of phenacetin-containing analgesics in the 1960s. Partial resection with preservation of the renal parenchyma was possible in the majority of patients. Survival for patients with bilateral tumors did not differ from that of patients with unilateral tumors.