Factores de riesgo de enfermedad residual en la re-RTU en una gran cohorte de pacientes con enfermedad T1G3 / Risk factors for residual disease at re-TUR in a large cohort of T1G3 patients

Introducción y objetivos: Los objetivos de la resección transuretral (RTU) del tumor vesical son la resección completa de las lesiones y la realización de un diagnóstico correcto con el objetivo de estadificar adecuadamente al paciente. Es bien sabido que la presencia de músculo detrusor en el espécimen es un requisito previo para minimizar el riesgo de infraestadificación.La persistencia de enfermedad tras la resección de los tumores vesicales no es infrecuente, y es la razón por la que las guías europeas recomiendan una re-resección transuretral (re-RTU) para todos los tumores T1. Recientemente se ha publicado que, en los casos con inclusión de músculo en el espécimen, la re-RTU no afecta la progresión ni la supervivencia específica del cáncer.Presentamos aquí los factores relacionados con el paciente y el tumor que pueden influir en la presencia de enfermedad residual en la re-RTU.Material y métodosDe nuestra cohorte retrospectiva de 2.451 pacientes con tumores T1G3 primarios tratados inicialmente con bacilo de Calnette-Guérin (BCG), están disponibles los resultados patológicos de 934 pacientes (38,1%) que se sometieron a una re-RTU. El 74% tenía tumores multifocales, el 20% de los tumores tenía más de 3 cm de diámetro y el 26% tenía carcinoma in situ (CIS) concomitante. En este subgrupo de pacientes que se sometieron a una segunda RTU, no hubo enfermedad residual en 267 pacientes (29%) y se presentó enfermedad residual en 667 pacientes (71%): Ta en 378 (40%) y T1 en 289 (31%) pacientes. Se analizaron la edad, el sexo, el estado del tumor (primario/recurrente), la terapia intravesical previa, el tamaño del tumor, la multifocalidad del tumor, la presencia de CIS concomitante y la inclusión de músculo en el espécimen para evaluar los factores de riesgo de enfermedad residual en la re-RTU, tanto en los análisis univariantes, como en las regresiones logísticas multivariantes. (AU)

Introduction and objectives: The goals of transurethral resection of a bladder tumor (TUR) are to completely resect the lesions and to make a correct diagnosis in order to adequately stage the patient. It is well known that the presence of detrusor muscle in the specimen is a prerequisite to minimize the risk of under staging.Persistent disease after resection of bladder tumors is not uncommon and is the reason why the European Guidelines recommended a re-TUR for all T1 tumors. It was recently published that when there is muscle in the specimen, re-TUR does not influence progression or cancer specific survival.We present here the patient and tumor factors that may influence the presence of residual disease at re-TUR.Material and methodsIn our retrospective cohort of 2451 primary T1G3 patients initially treated with BCG, pathology results for 934 patients (38.1%) who underwent re-TUR are available. 74% had multifocal tumors, 20% of tumors were more than 3 cm in diameter and 26% had concomitant CIS.In this subgroup of patients who underwent re-TUR, there was no residual disease in 267 patients (29%) and residual disease in 667 patients (71%): Ta in 378 (40%) and T1 in 289 (31%) patients. Age, gender, tumor status (primary/recurrent), previous intravesical therapy, tumor size, tumor multi-focality, presence of concomitant CIS, and muscle in the specimen were analyzed in order to evaluate risk factors of residual disease at re-TUR, both in univariate analyses and multivariate logistic regressions. (AU)

Risk factors for residual disease at re-TUR in a large cohort of T1G3 patients.

INTRODUCTION AND OBJECTIVES: The goals of transurethral resection of a bladder tumor (TUR) are to completely resect the lesions and to make a correct diagnosis in order to adequately stage the patient. It is well known that the presence of detrusor muscle in the specimen is a prerequisite to minimize the risk of under staging. Persistent disease after resection of bladder tumors is not uncommon and is the reason why the European Guidelines recommended a re-TUR for all T1 tumors. It was recently published that when there is muscle in the specimen, re-TUR does not influence progression or cancer specific survival. We present here the patient and tumor factors that may influence the presence of residual disease at re-TUR. MATERIAL AND METHODS: In our retrospective cohort of 2451 primary T1G3 patients initially treated with BCG, pathology results for 934 patients (38.1%) who underwent re-TUR are available. 74% had multifocal tumors, 20% of tumors were more than 3 cm in diameter and 26% had concomitant CIS. In this subgroup of patients who underwent re-TUR, there was no residual disease in 267 patients (29%) and residual disease in 667 patients (71%): Ta in 378 (40%) and T1 in 289 (31%) patients. Age, gender, tumor status (primary/recurrent), previous intravesical therapy, tumor size, tumor multi-focality, presence of concomitant CIS, and muscle in the specimen were analyzed in order to evaluate risk factors of residual disease at re-TUR, both in univariate analyses and multivariate logistic regressions. RESULTS: The following were not risk factors for residual disease: age, gender, tumor status and previous intravesical chemotherapy. The following were univariate risk factors for presence of residual disease: no muscle in TUR, multiple tumors, tumors > 3 cm, and presence of concomitant CIS. Due to the correlation between tumor multi-focality and tumor size, the multivariate model retained either the number of tumors or the tumor diameter (but not both), p < 0.001. The presence of muscle in the specimen was no longer significant, while the presence of CIS only remained significant in the model with tumor size, p < 0.001. CONCLUSIONS: The most significant factors for a higher risk of residual disease at re-TUR in T1G3 patients are multifocal tumors and tumors more than 3 cm. Patients with concomitant CIS and those without muscle in the specimen also have a higher risk of residual disease.

The impact of fluid optimisation before induction of anaesthesia on hypotension after induction.

Intra-operative hypotension is a known predictor of adverse events and poor outcomes following major surgery. Hypotension often occurs on induction of anaesthesia, typically attributed to hypovolaemia and the haemodynamic effects of anaesthetic agents. We assessed the efficacy of fluid optimisation for reducing the incidence of hypotension on induction of anaesthesia. This prospective trial enrolled 283 patients undergoing radical cystectomy and randomly allocated them to goal-directed fluid therapy (n = 142) or standard fluid therapy (n = 141). Goal-directed fluid therapy patients received fluid optimisation based on stroke volume response to passive leg raise before induction; those with positive passive leg raise received intravenous crystalloid fluid boluses until stroke volume was optimised. Baseline mean arterial pressure was measured on the morning of surgery and on arriving in the operating theatre. This post-hoc analysis defined haemodynamic instability as either a > 30% relative drop in mean arterial pressure compared with baseline or absolute mean arterial pressure < 55 mmHg, within 15 min of induction. Forty-two (30%) goal-directed fluid therapy patients underwent fluid optimisation after finding an intravascular fluid deficit via passive leg raise testing; 106 (75%) goal-directed fluid therapy and 112 (79%) standard fluid therapy patients met criteria for haemodynamic instability. There was no significant difference in the incidence of haemodynamic instability between the goal-directed fluid therapy and standard fluid therapy groups using absolute mean arterial pressure drop below 55 mmHg (p = 0.58) or using pre-surgical testing or pre-surgical mean arterial pressure values as baseline (p = 0.21, p = 0.89, respectively); however, the difference in the incidence of haemodynamic instability was significant using the operating theatre baseline mean arterial pressure (p = 0.004). We conclude that fluid optimisation before induction of general anaesthesia did not significantly impact haemodynamic instability.

Predictors of oncological outcomes in T1G3 patients treated with BCG who undergo radical cystectomy.

PURPOSE: To evaluate the oncological impact of postponing radical cystectomy (RC) to allow further conservative therapies prior to progression in a large multicentre retrospective cohort of T1-HG/G3 patients initially treated with BCG. METHODS: According to the time of RC, the population was divided into 3 groups: patients who did not progress to muscle-invasive disease, patients who progressed before radical cystectomy and patients who experienced progression at the time of radical cystectomy. Clinical and pathological outcomes were compared across the three groups. RESULTS: Of 2451 patients, 509 (20.8%) underwent RC. Patients with tumors > 3 cm or with CIS had earlier cystectomies (HR = 1.79, p = 0.001 and HR = 1.53, p = 0.02, respectively). Patients with tumors > 3 cm, multiple tumors or CIS had earlier T3/T4 or N + cystectomies. In patients who progressed, the timing of cystectomy did not affect the risk of T3/T4 or N + disease at RC. Patients with T3/T4 or N + disease at RC had a shorter disease-specific survival (HR = 4.38, p < 0.001), as did patients with CIS at cystectomy (HR = 2.39, p < 0.001). Patients who progressed prior to cystectomy had a shorter disease-specific survival than patients for whom progression was only detected at cystectomy (HR = 0.58, p = 0.024) CONCLUSIONS: Patients treated with RC before experiencing progression to muscle-invasive disease harbor better oncological and survival outcomes compared to those who progressed before RC and to those upstaged at surgery. Tumor size and concomitant CIS at diagnosis are the main predictors of surgical treatment while tumor size, CIS and tumor multiplicity are associated with extravesical disease at surgery.

Recurrence, progression and cancer-specific mortality according to stage at re-TUR in T1G3 bladder cancer patients treated with BCG: not as bad as previously thought.

PURPOSE: The goals of transurethral resection of a bladder tumor (TUR) are to completely resect the lesions and to make a correct diagnosis to adequately stage and treat the patient. Persistent disease after TUR is not uncommon and is why re-TUR is recommended in T1G3 patients. When there is T1 tumor in the re-TUR specimen, very high risks of progression (82%) have been reported. We analyze the risks of recurrence, progression to muscle-invasive disease and cancer-specific mortality (CSM) according to tumor stage at re-TUR in T1G3 patients treated with BCG. METHODS: In our retrospective cohort of 2451 T1G3 patients, 934 patients (38.1%) underwent re-TUR. 667 patients had residual disease (71.4%): Ta in 378 (40.5%), T1 in 289 (30.9%) patients. Times to recurrence, progression and CSM in the three groups were estimated using cumulative incidence functions and compared using the Cox regression model. RESULTS: During a median follow-up of 5.2 years, 512 patients recurred. The recurrence rate was significantly higher in patients with a T1 at re-TUR (P < 0.001). Progression rates differed according to the pathology at re-TUR, 25.3% in T1, 14.6% in Ta and 14.2% in case of no residual tumor (P < 0.001). Similar trends were seen in both patients with and without muscle in the original TUR specimen. CONCLUSIONS: Patients with T1G3 tumors and no residual disease or Ta at re-TUR have better recurrence, progression and CSM rates than previously reported, with a CSM rate of 13.1 and a 25.3% progression rate in re-TUR T1 disease.

Radical cystectomy and orthotopic urinary reconstruction in patients with bladder cancer after renal transplantation: clinical outcomes and description of technique.

OBJECTIVES: Radical cystectomy (RC) with pelvic lymph node dissection and urinary diversion is the standard treatment for muscle-invasive bladder cancer. In the setting of prior renal transplantation, surgical treatment remains the mainstay but is technically challenging. We report our patient outcomes in this unique population with a description of the technique. METHODS: We identified five patients with a history of renal transplantation who underwent RC and orthotopic urinary diversion. Preoperative clinical and demographic features were compiled and disease-specific and functional outcomes were assessed. Intraoperative technical challenges and maneuvers for avoiding complications are highlighted. RESULTS: Four patients were male and one was female, with a median age of 64 years. Gross hematuria was the most common sign at presentation. Clinical staging was T2, T2 with carcinoma in situ (CIS), high-grade (HG) Ta with CIS, T2 with squamous differentiation, and HG T1, and pathologic tumor stage was pTisN1, pT3N0, pTisN0, pT3N0, and pT0N0, respectively. One patient received a Studer-type diversion and four underwent Hautmann diversion. Median follow-up after cystectomy was 12.9 months. Graft ureteral identification was aided by the use of intravenous dye in all patients. Ipsilateral pelvic lymph node dissection was not possible in any patient. All patients are alive at follow-up, with two experiencing recurrence at 7.2 months and 66.8 months. No patient experienced a significant decrease in estimated creatinine clearance postoperatively. Postoperative daytime control was reported by all patients whereas two noted complete nighttime control. CONCLUSIONS: RC with orthotopic diversion is a technically demanding procedure in patients with a history renal transplantation. Meticulous technique and careful attention to the altered anatomy are required for successful outcomes.

Prospective evaluation of MRI, ¹¹C-acetate PET/CT and contrast-enhanced CT for staging of bladder cancer.

PURPOSE: To prospectively evaluate the diagnostic performance of magnetic resonance imaging (MRI), (11)C-acetate positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT for bladder cancer staging, using whole-mount pathologic review of radical cystectomy and pelvic lymph node specimens as the reference standard. MATERIALS AND METHODS: The institutional review board approved this prospective study, which was compliant with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from 16 patients with histologically confirmed bladder cancer who underwent MRI, (11)C-acetate PET/CT and contrast-enhanced CT before radical cystectomy and pelvic lymph node dissection. Before imaging 4/16 patients had received intravesical Bacillus Calmette-Guérin treatment, 6 had received systemic chemotherapy, 3 had received both and 3 had received neither. Measures of diagnostic performance including accuracy, sensitivity and specificity were estimated separately for each imaging modality. RESULTS: MRI correctly staged 56% of patients (9/16), overstaged 38% (6/16) and understaged 6% (1/16). CT correctly staged 50% of patients (8/16), overstaged 44% (7/16) and understaged 6% (1/16). In 9 patients, (11)C-acetate PET/CT showed uptake within the bladder wall; the uptake was true-positive in 7 patients and false-positive in 2 patients. Of the remaining 7 patients, 5 had true-negative and 2 had false-negative PET/CT results for cancer in the bladder wall. For all modalities, staging accuracy was reduced in patients with a history of prior intravesical and/or systemic chemotherapy. CONCLUSION: In staging bladder cancer, MRI, (11)C-acetate PET/CT and CT displayed similar levels of accuracy. For all modalities, a history of intravesical and/or systemic chemotherapy affected staging accuracy.

Joint association of polymorphism of the FGFR4 gene and mutation TP53 gene with bladder cancer prognosis.

The impact of the fibroblast growth factor receptor 4 (FGFR4) Gly388Arg polymorphism on bladder cancer is unknown. We found no clear correlations between the FGFR4 genotype and risk of bladder cancer or pathological parameters. Neither the polymorphism nor TP53 mutation status was an independent predictor of prognosis, but they might act jointly on the disease-specific survival of patients.

Results of high dose rate brachytherapy, anterior pelvic exenteration and external beam radiotherapy for carcinoma of the female urethra.

PURPOSE: We evaluated a multimodality approach to locally advanced urethral carcinoma in women. MATERIALS AND METHODS: Between August 1996 and July 1999, 6 women were treated for locally advanced carcinoma of the urethra with anterior pelvic exenteration followed by high dose 192iridium intraoperative radiation therapy. Four of the 6 patients were also treated with neoadjuvant or concomitant platinum based chemotherapy. RESULTS: Two patients had no evidence of disease, 3 had distant metastasis and 2 had local recurrence at a mean followup of 21 months (range 12 to 47). Radiation was relatively well tolerated with no major adverse events. CONCLUSIONS: High dose intraoperative brachytherapy followed by external beam radiation is relatively well tolerated. Local control seems to have improved. We must evaluate a larger cohort of patients to determine this impact of the combined modality on local control and patient survival.

Genetic alterations in tp53 in recurrent urothelial cancer: a longitudinal study.

PURPOSE: Because bladder cancer has a recurrence rate that can be as high as 90% at 2 years, we sought to clarify whether these metachronous tumors are polyclonal or monoclonal in origin. We have examined the genetic alterations of the TP53 gene in a cohort of patients with urothelial cancer who underwent multiple biopsies at different times and sites because of tumor recurrence and/or progression. We postulated that if tumor cells at different points in the natural history of the disease contain an identical mutation in the TP53 gene, this pattern could provide evidence for the monoclonality of the recurrent bladder tumors. EXPERIMENTAL DESIGN: Fifty-three biopsy specimens from 13 patients at different times and sites were selected for this study. Microdissection was used to ensure the purity of tumor cells. DNA extraction, PCR, and direct sequencing of exons 5 through 8 of the TP53 gene were conducted following protocols optimized in our laboratory. RESULTS: We found that specimens from seven patients carried tumor-specific TP53 mutations. The number of lesions in these patients ranged from two to seven, extending from 2 to 4 years. All of the seven patients displayed identical mutations in the different microdissected tumors. CONCLUSIONS: On the basis of these data, it appears that the recurrent bladder tumors originate from the same clone.

[Arachidonic acid and prostaglandins, inflammation and oncology]. / Acide arachidonique et prostaglandines, inflammation et oncologie.

CYCLOOXYGENASE PATHWAY: Among the 3 metabolic pathways leading to oxidation of arachidonic acid, the cyclooxygenase (COX) pathway produces prostaglandin G2 that is rapidly transformed into prostaglandin H2. PROSTAGLANDINS: Prostaglandins are inflammation mediators that are strongly implicated in tumorgenesis. They participate in tumor initiation, promotion and growth. INFLAMMATION AND EPITHELIAL CANCER: Chronic inflammation is a risk factor for epithelial cancer. It induces prostaglandin synthesis via activation of COX-2. There is a cause and effect relationship between chronic inflammation and carcinogeneis via COX-2 expression. It has been demonstrated that COX-2 favors tumor invasion and inhibits apoptosis. Tumor growth is favored by PGE2-induced reduction in immunity; COX-2 inhibitors reinforce the immune response. Finally COX-2 is expressed in tumor neovessels and plays a role in angiogenesis.

[Cyclooxygenases]. / Les cyclooxygénases.

TWO ISOFORMS: There are two isoforms of cyclooxygenase (COX) with similar structure and metabolic activity. COX-1 is a constitutional enzyme. COX-2 is an inductible form. CYCLOOXYGENASE-1: COX-1 is present in most tissues, particularly in the kidney, the digestive tract mucosa, platelets, brain, liver and spleen. CYCLOOXYGENASE-2: COX-2 expression can be induced by an inflammatory process. Implicated in the development of certain cancers, COX-2 is expressed in numerous tumor cell lines and in most epithelial carcinomas. COX-2 favors tumor invasion and inhibits apoptosis. When it is absent, tumor growth is slower or stopped.

[Cyclooxygenase inhibitors]. / Les inhibiteurs des cyclooxygénases.

DISTINCT EFFECTS: Since the discovery of the two isoforms of COX, the therapeutic effects of nonsteroidal antiinflammatory drugs (NSAID) can be distinguished from their adverse effects linked to the inhibition of the constitutional form via selective inhibition of the inducible form. Non-selective NSAID that inhibit both COX isoforms are difficult to use for long-term regimens. NSAID AND CANCER PREVENTION: Epidemiology studies and animal and in vitro studies have demonstrated that regular use of NSAID reduced the incidence of colorectal cancer and certain precancer lesions. PROMISING PERSPECTIVES: COX-2 specific inhibitors, for example cerecoxib or rofecoxib, are potentially interesting for human therapy for chemoprevention of epithelial cancer or as medical treatment, alone or in combination with other anticancer treatments.

Cystectomy for bladder cancer: a contemporary series.

PURPOSE: To validate the current TNM staging system, we analyzed our contemporary experience with 300 cystectomies. MATERIALS AND METHODS: The pathological material and medical records of 300 patients treated with cystectomy were reviewed, and the new TNM classification was adopted. RESULTS: The median followup of patients with no evidence of disease was 65 months, and overall survival rate was 45% with a median survival of 50 months. In a Cox regression analysis only patient age, pT stage and neoadjuvant chemotherapy were significant factors for survival. The disease specific survival was 67% with a median survival of 94 months. In a multiple proportional hazards analysis only pT stage and previous chemotherapy were significant factors of disease specific survival. A significant difference was seen in the overall and disease specific survival between patients with organ confined and nonorgan confined tumors. We did not observe a difference in the survival rate among patients with pT4a to pT3 tumors. Significant differences were not seen in survival rates between sexes or among patients of different age groups. Transitional cell carcinoma was the predominant histological type, and no significant difference was found in patient outcome among the different histological subtypes. CONCLUSIONS: Bladder cancer can be categorized into organ confined and nonorgan confined tumors. This dichotomous grouping is better suited for evaluating adjuvant clinical trials. The pT stage of the bladder and prostate should be prospectively analyzed together to better define the clinical implications of prostatic involvement. In our opinion the histological subtypes do not affect outcome.

Current use and questions concerning intravesical bladder cancer group for superficial bladder cancer.

Bacille Calmette-Guerin (BCG) is the most effective therapy for CIS of the bladder. Although several series have shown a decrease in recurrence and progression of T1 tumor, this effect is temporary. More than one half of patients with T1 tumors treated with BCG will progress over the longterm. A second course of BCG is indicated after an initial complete response. There is no definitive answer regarding the efficacy of maintenance therapy or the optimum dose of BCG. Randomized trials are needed to address these issues in a more conclusive manner. Phase III trials have shown that mitomycin C can be as effective as BCG in the management of papillary tumors; however, BCG is more effective in patients with CIS and high-risk superficial tumors.

Toxicology and pharmacokinetics of intravesical gemcitabine: a preclinical study in dogs.

More active and well-tolerated agents are needed for the treatment of superficial bladder cancer. This study investigated intravesical gemcitabine to establish the toxicology and pharmacokinetics necessary for clinical trials. Beagle dogs (in groups of 2; n = 6) received 100 mg, 350 mg, or 1 g of drug by intravesical administration on alternate days three times/week for 4 weeks. Animals were observed for clinical signs of toxicity; gemcitabine levels and peripheral blood counts were taken three times weekly. The dogs were euthanized, and a full necropsy was performed at days 1 and 14 after the last dose. Intravesical gemcitabine was given at 100 mg (n = 2), 350 mg (equivalent to the 1000 mg/m2 human dose; n = 3), and 3.5 g (n = 1). i.v. gemcitabine was given at 350 mg (n = 2). Plasma samples drawn at time points up to 8 h were analyzed for systemic absorption and clearance of drug. Doses of 100 and 350 mg were well tolerated with no clinical side effects. Necropsies revealed normal bone marrow cellularity and normal bladder histology. At 1 g, signs of severe clinical toxicity were evident, and after only three doses, necropsies demonstrated severe bone marrow hypoplasia, cystitis, and intestinal necrosis. At all intravesical doses, significant systemic absorption was seen. The T1/2 (+/- SD) for intravesical and i.v. administration of 350 mg was 328 (+/-6.8) min and 99.3 (+/-5.2) min, respectively (P<0.001). Intravesical gemcitabine is well tolerated and has no direct bladder toxicity at doses up to 1000 mg/m2. Higher doses result in gastrointestinal, bladder, and bone marrow toxicity.

Is transurethral biopsy of the bladder necessary after 3 months to evaluate response to bacillus Calmette-Guerin therapy?

PURPOSE: We assessed the need for transurethral biopsy of the bladder at the 3-month evaluation in patients who have received intravesical bacillus Calmette-Guerin (BCG). MATERIALS AND METHODS: A total of 81 patients collectively received 83, 6-week courses of BCG between 1995 and 1997, and underwent transurethral bladder biopsies 3 months after initiation of immunotherapy. The pretreatment and posttreatment bladder biopsy results, urinary cytology and posttreatment cystoscopic findings were correlated. RESULTS: Transitional cell carcinoma was demonstrated in 5 of 11 patients with erythematous bladder mucosa and a positive cytology compared to none of 37 with an erythematous lesion and a negative cytology. Of 12 patients with a papillary lesion on cystoscopy and a positive biopsy 10 had a negative cytology, and only 1 of 13 patients with a negative cystoscopy had a positive biopsy. CONCLUSIONS: Bladder biopsy is not necessary in patients 3 months after receiving BCG who have a normal office cystoscopy or an erythematous bladder and normal urine cytology.

Male urethral carcinoma: analysis of treatment outcome.

OBJECTIVES: To evaluate our experience with primary carcinomas of the male urethra and to analyze the impact of tumor variables and treatment on overall, disease-specific, local recurrence-free, and metastasis-free survival. METHODS: Between 1958 and 1996, we identified 46 men with primary carcinoma of the bulbar and anterior urethra. The median follow-up was 125 months (1 to 336). The patients were stratified by stage, nodal status, histologic type, treatment, type of surgery, site of disease, year at diagnosis, and smoking status. RESULTS: The overall survival and disease-specific survival rates at 5 years were 42% and 50%, respectively. The recurrence-free survival and metastasis-free survival rates at 5 years were 51% and 56%, respectively. The overall survival rate was 83% for superficial disease versus 36% for invasive tumors. The overall survival rate was 26% for tumors of the bulbar urethra versus 69% for tumors of the anterior urethra. CONCLUSIONS: Current modalities of treatment are ineffective for local control and survival. New treatment strategies are needed for urethral cancer.

Prognostic significance of transcription factor E2F-1 in bladder cancer: genotypic and phenotypic characterization.

BACKGROUND: We sought to identify and characterize potential alterations in E2F-1, a transcription factor that binds to the retinoblastoma protein (pRB), in bladder neoplasms and to elucidate a possible role for E2F-1 as an oncogene or a tumor suppressor gene. METHODS: Tumor samples from 133 evaluable patients with bladder cancer were analyzed for E2F-1 gene mutations by use of polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. In addition, tumors were studied for E2F-1 and pRB protein expression by use of immunohistochemistry. Results from the above analyses were correlated with clinicopathologic parameters and outcome. All P values are two-sided. RESULTS: A polymorphism, consisting of a nucleotide change at amino acid codon 393 in exon 7 (GGC-->AGC [Gly-->Ser]), was identified in seven of 133 case patients, being present in both tumor and corresponding normal tissues. No bandshifts were identified in the nuclear-localization or DNA-binding domains on PCR-SSCP analysis. On immunohistochemical analysis, E2F-1 nuclear reactivity was observed in less than 5% of the cells from 53 tumors and in 5%-75% of the cells from the remaining 80 tumors. The pattern of E2F-1 protein expression was not altered in relation to the identified polymorphism. pRB nuclear reactivity greater than 20% (of tumor cells stained) was present in 66% of the samples. E2F-1 nuclear reactivity correlated inversely with the percentage of cells showing pRB reactivity (Kendall tau(b) = -0.18; P = .019). On multivariate analysis, patients with lower E2F-1 reactivity had statistically significantly increased risks of progression to metastases (P = .001) and death (P = .02). CONCLUSIONS: E2F-1 alterations occur at the phenotypic level, rather than at the genotypic level, in bladder cancer. The adverse outcome for patients whose tumors exhibit low E2F-1 nuclear expression suggests a possible tumor suppressor role for E2F-1 in bladder cancer.