International cancer seminars: a focus on kidney cancer.

Recent years have seen important advances in our understanding of the etiology, biology and genetics of kidney cancer. To summarize important achievements and identify prominent research questions that remain, a workshop was organized by IARC and the US NCI. A series of 'difficult questions' were formulated, which should be given future priority in the areas of population, genomic and clinical research.

Plasma osteopontin concentrations in patients with cutaneous melanoma.

An effective circulating tumour marker is needed for melanoma especially with the advent of targeted therapies. Gene expression studies examining primary melanomas have shown that increased expression of osteopontin (SPP1) is associated with poor prognosis. Studies subsequently reported higher blood levels in melanoma patients with metastatic disease than those without. This study was designed to determine whether osteopontin plasma concentrations in disease-free patients after initial treatment predict survival. An enzyme-linked immunosorbent assay (ELISA) was used to measure osteopontin levels in stored plasma samples (N=215) from participants in the Leeds Melanoma Cohort. AJCC stage at sampling was statistically significant associated with osteopontin levels (p=0.03). Participants with untreated stage IV disease at sampling (n=10) had higher median osteopontin levels compared to those with treated stage I-III disease (n=158) (p<0.001) confirming previous findings. There was a trend for increased risk of death with increasing osteopontin levels but this was not statistically significant. If a level of 103.14 ng/ml (95th centile of healthy controls) was taken as the upper end of the normal range then 2.5% of patients with treated stage I-III (4/110), 17.6% of patients with untreated stage III (3/17) and 30% of patients with untreated stage IV disease (3/10) had higher levels. These findings suggest that plasma osteopontin levels warrant investigation as a tumour marker in a larger study in which the significance of change in levels over time should be studied in relation to detectable disease recurrence.

miR-210 is a target of hypoxia-inducible factors 1 and 2 in renal cancer, regulates ISCU and correlates with good prognosis.

BACKGROUND: Clear cell renal cancer frequently harbours von Hippel-Lindau (VHL) gene mutations, leading to stabilisation of the hypoxia-inducible factors (HIFs) and expression of their target genes. We investigated HIF-1 and HIF-2 in the regulation of microRNA-210 (miR-210), and its clinical relevance in renal tumours. METHODS: RCC4 and 786-O renal cancer cell lines transfected with either an empty vector or functional VHL and incubated in normoxia or hypoxia were examined for miR-210 expression. Hypoxia-inducible factor siRNAs were used to examine their regulation of miR-210. Seventy-one clear cell renal tumours were sequenced for VHL mutations. Expression of miR-210, VHL, CA9, ISCU and Ki-67 were determined by immunohistochemistry and qRT-PCR. RESULTS: In addition to HIF-1 regulating miR-210 in renal cancer, HIF-2 can regulate this microRNA in the absence of HIF-1. MicroRNA-210 is upregulated in renal cancer compared with normal renal cortex tissue. MicroRNA-210 correlates negatively with its gene target ISCU at the protein and mRNA level. MicroRNA-210 correlated with positive outcome variables and negatively with Ki-67. CONCLUSION: We provide further evidence of miR-210 activity in vivo, and show that high miR-210 expression is associated with better clinico-pathological prognostic factors.

Prognostic utility of pre-operative circulating osteopontin, carbonic anhydrase IX and CRP in renal cell carcinoma.

BACKGROUND: Objectively measured circulating biomarkers of prognosis complementing existing clinicopathological models are needed in renal cell carcinoma (RCC). METHODS: Blood samples collected from 216 RCC patients in Leeds before nephrectomy (median follow-up 7 years) were analysed for C-reactive protein (CRP), osteopontin (OPN) and carbonic anhydrase IX (CA9) and prognostic significance determined. RESULTS: CA9, OPN and CRP were univariately prognostic for overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) with CRP and CA9 being independently prognostic for OS/CSS and OS, respectively. Including CA9, OPN and CRP with other conventional prognostic factors gave a superior predictive capacity when compared with a previously published pre-operative clinical nomogram (Karakiewicz et al, 2009). Osteopontin outperformed this nomogram and the post-operative SSIGN score for OS but not for CSS, being significantly predictive for non-cancer deaths. Osteopontin, CRP and CA9 outperformed stage (c-index 76% compared with 70% for stage) and OPN or CA9 identified several subsets of poor prognosis patients including in T1 patients, who may benefit from adjuvant therapy and increased surveillance. CONCLUSION: Circulating CA9, OPN and CRP add value to existing clinicopathological prognostic factors/models and support further studies to investigate their potential use in improving the clinical management of RCC.

Genome-wide methylation analysis identifies epigenetically inactivated candidate tumour suppressor genes in renal cell carcinoma.

The detection of promoter region hypermethylation and transcriptional silencing has facilitated the identification of candidate renal cell carcinoma (RCC) tumour suppressor genes (TSGs). We have used a genome-wide strategy (methylated DNA immunoprecipitation (MeDIP) and whole-genome array analysis in combination with high-density expression array analysis) to identify genes that are frequently methylated and silenced in RCC. MeDIP analysis on 9 RCC tumours and 3 non-malignant normal kidney tissue samples was performed, and an initial shortlist of 56 candidate genes that were methylated by array analysis was further investigated; 9 genes were confirmed to show frequent promoter region methylation in primary RCC tumour samples (KLHL35 (39%), QPCT (19%), SCUBE3 (19%), ZSCAN18 (32%), CCDC8 (35%), FBN2 (34%), ATP5G2 (36%), PCDH8 (58%) and CORO6 (22%)). RNAi knockdown for KLHL35, QPCT, SCUBE3, ZSCAN18, CCDC8 and FBN2 resulted in an anchorage-independent growth advantage. Tumour methylation of SCUBE3 was associated with a significantly increased risk of cancer death or relapse (P=0.0046). The identification of candidate epigenetically inactivated RCC TSGs provides new insights into renal tumourigenesis.

Improving the accuracy of pre-operative survival prediction in renal cell carcinoma with C-reactive protein.

BACKGROUND: Validated objective biomarkers are needed for patients with renal cell carcinoma (RCC) to guide patient management and define high-risk populations for follow-up or for therapeutic purposes. METHODS: Patients undergoing nephrectomy for RCC (n=286 all stages, 84% with conventional clear cell type) were included with a median duration follow-up of 5 years. The prognostic significance of pre-operative haematological and biochemical variables, including C-reactive protein (CRP) values were examined and whether they added additional information to a recently published pre-operative scoring system was determined. RESULTS: C-reactive protein was the most significant predictor of overall survival (OS; χ(2)=50.9, P<0.001). Five-year OS for patients with CRP ≤ 15 mg l(-1) vs >15 mg l(-1) was 72% (95% CI 65-78%) and 33% (95% CI 23-44%), respectively. Similar results were seen for cancer-specific survival (CSS) and disease-free survival. On multivariate analysis, CRP remained highly significant for CSS (χ(2)=17.3, P<0.0001) and OS (χ(2)=9.8, P<0.002), in addition to other pre-operative variables including log of neutrophil/lymphocyte ratio, red blood cell count and white cell count. C-reactive protein was significant in addition to the pre-operative nomogram score (χ(2)=12.5, P=0.0004 for OS, χ(2)=16.2, P=0.0001 for CSS and χ(2)=8.6, P=0.003 for DFS) and was still significant when other pre-operative variables were included. CONCLUSION: C-reactive protein and other haematological and biochemical variables have independent prognostic significance in RCC and may enhance pre-operative scoring systems.

Association of serum amyloid A protein and peptide fragments with prognosis in renal cancer.

BACKGROUND: In renal cell carcinoma (RCC), the discovery of biomarkers for clinical use is a priority. This study aimed to identify and validate diagnostic and prognostic serum markers using proteomic profiling. METHODS: Pre-operative sera from 119 patients with clear cell RCC and 69 healthy controls was analysed by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry with stringent in-house quality control and analysis routines. Following identification of one prognostic peak as a fragment of serum amyloid A (SAA), total serum SAA and CRP were also determined by immunoassay for further validation. RESULTS: Several peptides were identified as having independent prognostic but not diagnostic significance on multivariable analysis. One was subsequently identified as a 1525 Da fragment of SAA (hazard ratio (HR)=0.26, 95% CI 0.08-0.85, P=0.026). This was weakly negatively correlated with total SAA, which was also of independent prognostic significance (HR=2.46, 95% CI 1.17-5.15, P=0.017). Both potentially strengthened prognostic models based solely on pre-operative variables. CONCLUSIONS: This is the first description of the prognostic value of this peptide in RCC and demonstrates proof of principle of the approach. The subsequent examination of SAA protein considerably extends previous studies, being the first study to focus solely on pre-operative samples and describing potential clinical utility in pre-operative prognostic models.

Pre-operative urinary cathepsin D is associated with survival in patients with renal cell carcinoma.

BACKGROUND: No circulating markers are routinely used for renal cancer. The objective of this pilot study was to investigate whether conditioned media (CM) from renal cancer cell lines contains potential biomarkers that, when measured in clinical fluids, have diagnostic or prognostic utility. METHODS: Comparative 2D PAGE profiling of CM from renal cell carcinoma (RCC) and normal renal cultures identified cathepsin D that was subsequently validated in urine samples from 239 patients and healthy and benign disease subjects. RESULTS: Urinary cathepsin D was found to be significantly associated with overall (OS) (hazard ratio, HR, 1.33, 95%CI [1.09-1.63], P=0.005) and cancer-specific survival (HR 1.36, 95%CI [1.07-1.74], P=0.013) in RCC patients on univariate analysis. An optimal cut point (211 ng ml(-1) micromolCr(-1)) around which to stratify patients by OS was determined. Five-year OS equal to/above and below this value was 47.0% (95%CI 35.4%, 62.4%) and 60.9% (48.8%, 76.0%), respectively. On multivariable analysis using pre-operative variables, cathepsin D showed some evidence of independent prognostic value for OS (likelihood ratio test P-value=0.056) although requiring further validation in larger patient numbers with sufficient statistical power to determine independent significance. CONCLUSION: These data establish an important proof of principle and show the potential of proteomics-based studies. Cathepsin D may be of value as a pre-operative urinary biomarker for RCC, alone or in combination.

An evaluation of a preparation of Mycobacterium vaccae (SRL172) as an immunotherapeutic agent in renal cancer.

Two studies were carried out to evaluate heat-killed Mycobacterium vaccae SRL172 as an immunotherapeutic agent for patients with metastatic, post-nephrectomy, renal cell carcinoma. In the first study, 60 patients in France and the UK received injections of SRL172, and their survival was compared with that of historical controls who had been treated either with biological response modifiers (IL-2, IFN-alpha) or chemotherapy. In the second study, 36 patients were randomised to receive treatment with IL-2 alone or IL-2 plus SRL172. Survival and adverse events related to the treatments were assessed and compared between treatment groups. The first study showed that those treated with SRL172 alone survived equally as long as those receiving IL-2 or IFN-alpha and both treatment groups survived longer than those on chemotherapy (p<0.001), a result supported by Cox's proportional hazards regression analysis. The second study, stopped early due to drug supply issues, showed that the addition of SRL172 to IL-2 made no difference to survival compared to IL-2 alone, in the limited numbers treated. Adverse events occurring in those receiving SRL172 in the first study were mild and in the second study those receiving IL-2 alone had significantly more adverse events than those receiving SRL172 plus IL-2 (p<0.001). It is concluded that SRL172 may have activity in metastatic renal cancer and has very low toxicity, making it worthy of further study.

Identification of novel VHL targets that are associated with the development of renal cell carcinoma.

von Hippel-Lindau (VHL) disease is a dominantly inherited family cancer syndrome characterized by the development of retinal and central nervous system haemangioblastomas, renal cell carcinoma (RCC) and phaeochromocytoma. Specific germline VHL mutations may predispose to haemangioblastomas, RCC and phaeochromocytoma to a varying extent. Although dysregulation of the hypoxia-inducible transcription factor-2 and JunB have been linked to the development of RCC and phaeochromocytoma, respectively, the precise basis for genotype-phenotype correlations in VHL disease have not been defined. To gain insights into the pathogenesis of RCC in VHL disease we compared gene expression microarray profiles in a RCC cell line expressing a Type 1 or Type 2B mutant pVHL (RCC-associated) to those of a Type 2A or 2C mutant (not associated with RCC). We identified 19 differentially expressed novel VHL target genes linked to RCC development. Eight targets were studied in detail by quantitative real-time polymerase chain reaction (three downregulated and five upregulated by wild-type VHL) and for six genes the effect of VHL inactivation was mimicked by hypoxia (but hypoxic-induction of smooth muscle alpha-actin 2 was specific for a RCC cell line). The potential role of four RCC-associated VHL target genes was assessed in vitro. NB thymosin beta (TMSNB) and proteinase-activated receptor 2 (PAR2) (both downregulated by wt pVHL) increased cell growth and motility in a RCC cell line, but aldehyde dehydrogenase (ALDH)1 and ALDH7 had no effect. These findings implicate TMSNB and PAR2 candidate oncogenes in the pathogenesis of VHL-associated RCC.

Phase I trial of intravesical Suramin in recurrent superficial transitional cell bladder carcinoma.

Suramin is an antitrypanosomal agent with antineoplastic activity, but with serious systemic side effects. We administered Suramin intravesically to determine a concentration with low toxicity but with evidence of a pharmacodynamic effect, to recommend a dose level for phase II trials. This was an open-labelled, non-randomized dose-escalation phase I study. In all, 12 patients with a history of recurrent superficial bladder cancer were grouped into four dose levels (10-150 mg ml(-1) in 60 ml saline). Six catheter instillations at weekly intervals were used. Cystoscopy and biopsy were performed before and 3 months after the start of treatment. Suramin was assayed using high-performance liquid chromatography, vascular endothelial growth factor (VEGF) using ELISA (enzyme-linked immunosorbent assay), and urinary protein profile using surface-enhanced laser desorption ionisation mass spectroscopy (SELDI). Minimal systemic absorption of Suramin was found at the highest dose of 150 mg ml(-1). Urinary VEGF was affected by Suramin at doses above 50 mg ml(-1), corresponding to the estimated threshold of saturation of Suramin binding to urine albumin. SELDI showed a specific disappearance of urinary protein peaks during treatment. Intravesical Suramin shows lack of toxicity and low systemic absorption. The results of this phase I trial support expanded clinical trials of efficacy at a dose of 100 mg ml(-1) intravesically.

Alumina-alumina artificial hip joints. Part I: a histological analysis and characterisation of wear debris by laser capture microdissection of tissues retrieved at revision.

The aims of this study were to investigate the tissues from uncemented Mittelmeier alumina ceramic-on-ceramic total hip replacements using histological methods and to isolate and characterise the ceramic wear debris using laser capture microdissection and electron microscopy. Tissues from around 10 non-cemented Mittelmeier alumina ceramic on ceramic THRs were obtained from patients undergoing revision surgery. Tissues were also obtained from six patients who were undergoing revisions for aseptic loosening of Charnley, metal-on-polyethylene prostheses. Tissue sections were analysed using light microscopy to determine histological reactions and also the location and content of alumina ceramic wear debris. Tissue samples were extracted from sections using laser capture microdissection and the characteristics of the particles subsequently analysed by TEM and SEM. The tissues from around the ceramic-on-ceramic prostheses all demonstrated the presence of particles, which could be seen as agglomerates inside cells or in distinct channels in the tissues. The tissues from the ceramic-on-ceramic retrievals had a mixed pathology with areas that had no obvious pathology, areas that were relatively rich in macrophages and over half of the tissues had in the region of 60% necrosis/necrobiosis. In comparison, the Charnley tissues showed a granulomatous cellular reaction involving a dense macrophage infiltrate and the presence of giant cells and < 30% necrosis/necrobiosis. The tissues from the ceramic prostheses also showed the presence of neutrophils and lymphocytes, which were not evident in the tissues from the Charnley retrievals. There were significantly more macrophages (p < 0.05), and giant cells (p < 0.01) in the Charnley tissues and significantly more neutrophils (p < 0.01) in the ceramic-on-ceramic tissues. TEM of the laser captured tissue revealed the presence of very small alumina wear debris in the size range 5-90 nm, mean size + SD of 24 +/- 19nm whereas SEM (lower resolution) revealed particles in the 0.05-3.2 microm size range. This is the first description of nanometre sized ceramic wear particles in retrieval tissues. The bi-modal size range of alumina ceramic wear debris overlapped with the size ranges commonly observed with metal particles (10-30 nm) and particles of ultra-high molecular weight polyethylene (0.1-1,000 microm). It is possible that the two size ranges of contributed to the mixed tissue pathology observed. It is speculated that the two types of ceramic wear debris are generated by two different wear mechanisms in vivo, under normal articulating conditions, relief polishing wear and very small wear debris is produced. while under conditions of microseparation of the head and cup and rim contact, intergranular and intragranular fracture and larger wear particles are generated.

Laser capture microdissection and proteomics: possibilities and limitation.

Tissue heterogeneity has always limited the information available from analysis of biological samples in the study of disease. Several approaches have been developed to address this problem, with laser capture microdissection (LCM) emerging as one of the methods of choice. LCM has been extensively used in combination with mutation detection studies and analyses of gene expression at the mRNA level and its potential in proteomics-based research is beginning to be realised. Here we review the progress made to date in the analysis of proteins in LCM-captured material and evaluate the scope and limitations of this approach.

Renal carcinoma cell lines inhibit natural killer activity via the CD94 receptor molecule.

MHC class I molecules protect normal and transformed cells from lysis by natural killer (NK) cells through recognition of receptors expressed on leucocytes. Defects in NK cell activity and lymphokine activated killer (LAK) cell generation have been previously demonstrated in patients with renal cell carcinoma (RCC). However, to date, the importance of NK receptor/MHC class I interactions for immune evasion by RCC cells has not been described. In this study, human RCC cell lines (HTB46, HTB47, ACHN, CRL 1933 and HTB44) were found to be susceptible to lysis by both NK cells and interleukin-15 (IL-15)-derived LAK cells from normal donors in vitro. However, when NK cells were co-cultured with RCC cells their expression of the CD94 NK receptor molecule was significantly increased and their cytolytic activity against RCC targets was reduced. The cytolytic activity of NK cells was restored by the addition of IL-15, which further augmented the expression of CD94 on CD56+ NK cells. Disruption of NK receptor-MHC class I interactions by the addition of blocking antibodies to CD94 had no effect on the lysis of K562 or HTB47 targets by NK cells. However, the sensitivity of HTB46 cells to NK-mediated lysis was increased by blocking the CD94 receptor molecule, but only when the NK cells had not been previously co-cultured with RCC cells. This was independent of the presence of IL-15. These results show that RCC cells can inhibit NK activity via CD94 and suggest that disruption of interactions between receptor and ligand on RCC cells in vivo may augment the immune response against tumours by innate effector cells.

Endotoxin, cytokines and lipid peroxides in children with intussusception.

BACKGROUND: Intussusception is a relatively common paediatric surgical emergency. The aim of this study was to investigate selected inflammatory mediators in children with acute intussusception and to identify potentially useful plasma markers of clinical outcome. METHODS: Clinical, radiographic, operative and pathological details were recorded prospectively of all children presenting to a single institution with a confirmed diagnosis of acute intussusception during 1 year. Paired acute and convalescent venous blood samples were collected in a standard manner for blinded analysis of the following: malondialdehyde, C-reactive protein (CRP), interleukin (IL) 6, neopterin, tumour necrosis factor alpha, endotoxin, and immunoglobulin (Ig) G and IgM antiendotoxin core antibody (EndoCAb). RESULTS: Thirty-two consecutive children (23 boys, nine girls) with a median age of 4 months were studied. Acute ileocolic intussusception was managed by air enema reduction (n = 19), operative reduction (n = 8) or surgical resection (n = 5). Peripheral blood cultures were sterile. Acute levels of plasma IL-6, neopterin and CRP were significantly raised in comparison to both normal laboratory ranges and convalescent samples (P < 0.001). Using stepwise discriminant analysis, CRP was identified as the best variable at distinguishing between the three treatment groups (P < 0.001). IgM EndoCAb concentrations were significantly greater in the convalescent sera of all the patients (P < 0.001). CONCLUSION: Acute ileocolic intussusception in childhood is associated with endotoxinaemia and significantly raised levels of circulating inflammatory cytokines. Plasma CRP at diagnosis showed a statistically significant positive correlation with disease severity.

Vascular endothelial growth factor (VEGF) in breast cancer: comparison of plasma, serum, and tissue VEGF and microvessel density and effects of tamoxifen.

The assessment of angiogenesis in breast cancer is of importance as a key indicator of survival and response to therapy. Circulating vascular endothelial growth factor (VEGF) measurements may provide a less subjective analysis than microvessel density (MVD) or immunohistochemical analysis of VEGF expression; however, most studies have used serum, which is now known to largely reflect platelet-derived VEGF concentrations. This study examined for the first time both plasma (VEGFp) and serum (VEGFs) VEGF concentrations in 201 blood samples from pre- and postmenopausal healthy controls and from patients with benign breast disease, localized breast cancer, breast cancer in remission, or metastatic breast cancer and related these to other clinicopathological markers. VEGFp but not VEGFs concentrations of patients with localized disease were significantly elevated compared with normal controls (P = 0.016). Patients with metastatic disease had higher VEGFp and VEGFs levels than normal controls (P < 0.001, P = 0.044 respectively), and higher VEGFp, but not VEGFs, than patients with benign disease (P = 0.009) and patients with localized disease (P = 0.004). However, the highest VEGFp and VEGFs concentrations were seen in patients in remission compared with normal controls (P < 0.001 and P = 0.008, respectively). VEGFp concentrations in patients in remission were also higher than in patients with benign disease (P = 0.01) or patients with localized disease (P = 0.005). Tamoxifen treatment was significantly associated with higher circulating and platelet-derived VEGF levels. Circulating VEGF did not correlate with any clinicopathological factor, including MVD or VEGF expression. VEGF expression was significantly correlated with estrogen receptor status and inversely correlated with tumor grade. MVD correlated with tumor size. Tamoxifen-induced increases in VEGF may be important in clinical prognosis or associated pathologies.

Subcutaneous administration of recombinant glycosylated interleukin 6 in patients with cancer: pharmacokinetics, pharmacodynamics and immunomodulatory effects.

This is the first report of the serum profile of a glycosylated recombinant form of human IL-6 (rhIL-6) administered subcutaneously (1-10 microg/kg/day) in a phase I/II trial as a thrombopoietic agent in patients with advanced cancer. The pharmacodynamic effects of IL-6 were also examined. Detailed pharmacokinetic measurements were made in four patients. Peak concentrations at 5-8 h and a median t0.5 of ca. 5 h were similar to those previously reported for non-glycosylated IL-6. However, higher peak concentrations and apparent differences in effective dose levels to those previously reported with the non-glycosylated form were seen. Indications of an apparent attenuation in circulating IL-6 concentrations with continuing injections were seen in eight of 10 patients examined but anti-IL-6 antibody generation was seen in only two patients. Soluble interleukin 6 receptor concentrations generally decreased. No major changes in T cell subsets were seen but expression of CD25 and CD54 by T lymphocytes significantly increased, accompanied by marked increases in soluble CD25 (sIL-2R) and CD54 (sICAM-1). No consistent change in B cells, monocytes or NK cells were seen. No evidence for induction of TNF-alpha was found. This study demonstrates similar biological effects of glycosylated rhIL-6 to those reported for the non-glycosylated form but illustrates several apparent differences which are discussed further.

Urological malignancies and the proteomic-genomic interface.

The urological malignancies, renal, bladder and prostate cancer, account for approximately 16% of all cancer cases. Unfortunately 5-year survival rates are relatively poor, largely a result of many cases not being diagnosed before the tumour has metastasised. There is a clear need for the identification of markers which will allow earlier detection of disease, and predict prognosis and response to therapy. In addition, they may be of use as therapeutic targets. Current advances in molecular biology are allowing the identification of a number of tumour-associated changes which could be of clinical use in the future. However, with the rapid technological advances being made in the field of proteomics, this approach could be integrated with genomics providing a complementary alternative, overcoming disparities between mRNA levels and protein production, and additionally allowing the identification of tumour-associated post-translational modifications. These approaches have already been used to identify novel genes and other cancer-related changes involved in the pathogenesis of urological malignancies. This review describes current progress in the genomic and proteomic study of urological malignancies, and highlights the potential of using proteomic technologies in the study of this group of diseases.

Urinary concentrations of the soluble adhesion molecule E-cadherin and total protein in patients with bladder cancer.

Reduced expression of the adhesion molecule E-cadherin has been associated with increased invasiveness and poorer survival in patients with bladder cancer. We have examined soluble E-cadherin (sE-cadherin) and total protein concentrations in urine from patients with bladder cancer (n = 34), non-neoplastic benign urological diseases (n = 14) and healthy controls (n = 21) to determine their diagnostic and prognostic significance. Soluble E-cadherin concentrations of the cancer group were significantly higher (P < 0.001) than those of the controls but the benign group was not significantly different from either the cancer group or the controls. When sE-cadherin concentrations were adjusted for creatinine, similar but more statistically significant results were obtained and the benign group was significantly elevated compared with the controls (P < 0.01). No differences were apparent between the invasive (pT1-4) and non-invasive (pTa) cancers. Urinary total protein concentrations in the cancer group were significantly higher than the controls (P < 0.001) and the benign group (P < 0.05) although no difference was seen between the benign group and patients with non-invasive (pTa) cancer or between the benign group and controls. When expressed as the protein/creatinine index, results were similar but more statistically significant and a significant difference was seen between invasive and non-invasive cancers (P < 0.01). Only the protein/creatinine index correlated significantly with stage of the tumour (P < 0.01). It is concluded that urinary sE-cadherin measurements are of no greater value than urinary total protein.