Current and future perspectives in advanced bladder cancer: is there a new standard?

Effect of Intravesical Instillation of Gemcitabine vs Saline Immediately Following Resection of Suspected Low-Grade Non-Muscle-Invasive Bladder Cancer on Tumor Recurrence: SWOG S0337 Randomized Clinical Trial

Importance

Low-grade non-muscle-invasive urothelial cancer frequently recurs after excision by transurethral resection of bladder tumor (TURBT).

Objective

To determine whether immediate post-TURBT intravesical instillation of gemcitabine reduces recurrence of suspected low-grade non-muscle-invasive urothelial cancer compared with saline.

Design, Setting, and Participants

Randomized double-blind clinical trial conducted at 23 US centers. Patients with suspected low-grade non-muscle-invasive urothelial cancer based on cystoscopic appearance without any high-grade or without more than 2 low-grade urothelial cancer episodes within 18 months before index TURBT were enrolled between January 23, 2008, and August 14, 2012, and followed up every 3 months with cystoscopy and cytology for 2 years and then semiannually for 2 years. Patients were monitored for tumor recurrence, progression to muscle invasion, survival, and toxic effects. The final date of follow-up was August 14, 2016.

Interventions

Participants were randomly assigned to receive intravesical instillation of gemcitabine (2 g in 100 mL of saline) (n = 201) or saline (100 mL) (n = 205) for 1 hour immediately following TURBT.

Main Outcomes and Measures

The primary outcome was time to recurrence of cancer. Secondary end points were time to muscle invasion and death due to any cause.

Results

Among 406 randomized eligible patients (median age, 66 years; 84.7% men), 383 completed the trial. In the intention-to-treat analysis, 67 of 201 patients (4-year estimate, 35%) in the gemcitabine group and 91 of 205 patients (4-year estimate, 47%) in the saline group had cancer recurrence within 4.0 years (hazard ratio, 0.66; 95% CI, 0.48-0.90; P<.001 by 1-sided log-rank test for time to recurrence). Among the 215 patients with low-grade non-muscle-invasive urothelial cancer who underwent TURBT and drug instillation, 34 of 102 patients (4-year estimate, 34%) in the gemcitabine group and 59 of 113 patients (4-year estimate, 54%) in the saline group had cancer recurrence (hazard ratio, 0.53; 95% CI, 0.35-0.81; P = .001 by 1-sided log-rank test for time to recurrence). Fifteen patients had tumors that progressed to muscle invasion (5 in the gemcitabine group and 10 in the saline group; P = .22 by 1-sided log-rank test) and 42 died of any cause (17 in the gemcitabine group and 25 in the saline group; P = .12 by 1-sided log-rank test). There were no grade 4 or 5 adverse events and no significant differences in adverse events of grade 3 or lower.

Conclusions and Relevance

Among patients with suspected low-grade non-muscle-invasive urothelial cancer, immediate postresection intravesical instillation of gemcitabine, compared with instillation of saline, significantly reduced the risk of recurrence over a median of 4.0 years. These findings support using this therapy, but further research is needed to compare gemcitabine with other intravesical agents.

Trial Registration

clinicaltrials.gov Identifier: NCT00445601.

Correlation of adverse effects of cisplatin administration in patients affected by solid tumours: a retrospective evaluation

Cisplatin is the most common antineoplastic drug used for the therapy of solid tumours. To date, researchers have focused on the dosage to be administered for each specific tumour, mainly considering the local adverse effects. The aim of this study was to correlate the severity of the adverse effects with: i) the dosage of cisplatin; ii) the specific site of the tumour; iii) the association with other drugs; and iv) the symptoms. We analysed data from 123 patients with 11 different tumour classes undergoing therapy from 2007 to 2008 at St. Anna Hospital (Ferrara, Italy), using the Spearman non-parametric correlation index. Even though significant correlations were found among the variables, the overall results showed that the main factor influencing the severity of the adverse effects was the dosage of cisplatin administered.

Solitary skin metastasis from sarcomatoid carcinoma of the bladder: a case report

INTRODUCTION

Cutaneous metastases from carcinomas of the bladder are very rare. They are related to advanced stages of the disease and have poor prognosis with low survival rates. The common treatment modality of cutaneous metastases from a primary bladder cancer is wide local excision followed by chemotherapy.

CASE PRESENTATION

We report a case of solitary skin metastasis from a rare type of urinary bladder carcinoma in a 68 year-old Caucasian man. Urinary bladder carcinoma metastasizing to the skin is an uncommon finding despite the high incidence of this tumor. Skin metastasis generally presents in the late stages of this disease and indicates a poor outcome.

CONCLUSIONS

Because of the extremely aggressive malignant potential of sarcomatoid carcinomas, the indications for a transurethral resection of the bladder should be carefully assessed and suitable therapeutic strategies should be examined further.

Predictive factors for response and prognostic factors for long-term survival in consecutive, single institution patients with locally advanced and/or metastatic transitional cell carcinoma following cisplatin-based chemotherapy

PURPOSE

The study was undertaken to identify pre-treatment clinical and histopathological factors of importance for response and survival after cisplatin-based combination chemotherapy, in patients with locally advanced or metastatic transitional cell carcinoma of the urothelium.

PATIENTS AND METHODS

Clinical, laboratory and histopathological data from 178 consecutive patients, representing all patients treated between 1991 and 2001 in a single institution, were collected. Correlations between these data and response and survival after chemotherapy were analysed using univariate and multivariate analyses.

RESULTS

Absence of visceral metastasis was the only parameter with independent correlation to the response to chemotherapy. Two of the analysed parameters were independently associated with increased survival: good performance status (PS< or =1) and absence of visceral metastases. Stratification of the patient material according to number of these risk-factors present showed strong association with survival.

CONCLUSION

It was possible to predict survival from pre-treatment clinical parameters and consequently it is possible to select groups with a high and low probability of obtaining long term survival following cisplatin-containing chemotherapy.

Bladder tumor markers: from hematuria to molecular diagnostics--where do we stand?

Bladder cancer is a common malignancy in the USA. Currently, the detection of initial tumors and recurrent disease is based on evaluation of voided urinary specimens, often followed by cystoscopy. With the high rate of recurrence, cystoscopies are regularly repeated with the aim of halting progression of the disease. For patients, this process is fraught with anxiety, pain and high cost. As a result, intense work is being done in the field of bladder tumor markers with the goal of identifying bladder cancer earlier, both in the initial diagnosis and in recurrences of known tumor. The possibility of identifying a marker that could noninvasively differentiate benign and malignant causes of hematuria, and identify recurrences prior to their pathologic progression is the objective of this area of research. Currently, a large number of tumor markers exist, each scrutinized in both the laboratory and in clinical trials. Here we present many of the most widely used and tested markers. Background details are provided as to the mechanism of detection of malignant cells, the results of recent trials and future directions of study. Some novel modalities for tumor detection are also presented. The next few years will no doubt bring newer markers and lead to the elimination of others. Studies continue to refine the role of these markers in clinical practice, but their ultimate efficacy will need to be borne out in large-scale clinical trials in a multitude of settings.

Gemcitabine plus docetaxel as first-line biweekly therapy in locally advanced and/or metastatic urothelial carcinoma: a phase II study

The purpose of the study was to evaluate objective response rate, survival and toxicity of the combination of gemcitabine-docetaxel administered on a biweekly schedule as first-line treatment in advanced/relapsed or metastatic urothelial carcinoma. Treatment consisted of the sequenced administration of gemcitabine 1500 mg/m(2) and docetaxel 60 mg/m(2) (2 h intravenous infusion) on days 1, 14 of a 28-day cycle for 6 months. A total of 33 patients, 22 men and 11 women, were enrolled, aged 41-75 years (median 64 years). The majority of patients had a good performance status (94%; status<2). Thirteen patients had locally advanced disease (39%) and 20 metastasic disease (41%). A total of 178 treatment cycles were administered with a median number of 5.4 cycles for a patients (range 2-8). Toxicity was primarily hematologic with the most frequent grade >2 being neutropenia (11%), with three episodes of febrile neutropenia. Anemia and thrombocytopenia were milder and had a lower incidence. The most frequent nonhematological toxicities were alopecia, followed by asthenia. Cardiac and pulmonary toxicity was minimal. No toxic deaths were recorded during study and follow-up. Overall response rate was 53.1%, including four complete responses (12.5%) and 13 partial responses (40.6%), whereas six patients (18.8%) had disease stabilization. Median time to progression was 10.2 months (95% confidence interval: 5.1-13.7), with a median survival of 14.8 months (95% confidence interval: 9.4-20.2) after an observation of 30 months (range 4-30+). The results of this study suggested that combination therapy with gemcitabine and docetaxel administered twice a week is particularly active and well tolerated as first-line treatment in advanced and/or metastatic urothelial carcinoma. Once data are confirmed in a larger study and longer follow-up, the favorable toxicity profile of this regimen may offer an interesting alternative to the cisplatin-based regimen.

Curcumin potentiates the apoptotic effects of chemotherapeutic agents and cytokines through down-regulation of nuclear factor-kappaB and nuclear factor-kappaB-regulated gene products in IFN-alpha-sensitive and IFN-alpha-resistant human bladder cancer cells

Bladder cancer mortality varies between the countries; whereas being highest in Western countries, it is lowest in Eastern countries, such as India. Cigarette smoking is one of the major risk factors for bladder cancer in affluent nations, such as United States. Localized early-stage bladder cancer is treated with resection and intravesical cytokine therapy, whereas metastatic cancer is typically treated with various combinations of systemic chemotherapy. Whether curcumin, a yellow curry pigment commonly consumed in countries, such as India, has any role in prevention or treatment of bladder cancer was investigated. We found that curcumin inhibited the proliferation, induced cell cycle arrest, and DNA fragmentation in both IFN-alpha-sensitive (RT4V6) and IFN-alpha-resistant (KU-7) bladder cancer cells. Curcumin also potentiated the apoptotic effects of the chemotherapeutic agents (gemcitabine and paclitaxel) and of cytokines [tumor necrosis factor (TNF) and TNF-related apoptosis-inducing ligand]. This effect of curcumin was independent of sensitivity and resistance to IFN-alpha, commonly used for treatment of bladder cancer. Whether the effects of curcumin are mediated through modulation of the nuclear factor-kappaB (NF-kappaB) pathway known to mediate antiapoptosis was investigated. Both gemcitabine and TNF activated NF-kappaB in bladder cancer cells and curcumin suppressed this activation. Similarly, cigarette smoke, a major risk factor for bladder cancer, also activated NF-kappaB and curcumin suppressed it. Cigarette smoke-induced expression of the NF-kappaB-regulated gene products cyclooxygenase-2 and vascular endothelial growth factor, linked with proliferation and angiogenesis, respectively, was also down-regulated by curcumin.

Therapie und Nachsorge bei malignen Blasentumoren

Treatment and follow up of bladder cancer strongly depends on stage and differentiation of the tumour. Superficial bladder tumours can mostly be controlled by transurethral resection followed by early intravesical application of a chemotherapeutic agent and a further close meshed follow-up. Generally, for muscle-invasive tumours radical cystectomy is indicated, whereas organ-spearing treatment due to combined therapeutic concepts can be offered in selected cases. For advanced and metastatic tumours, despite good response of bladder cancer to chemotherapy, prognosis is still poor. However, implementation of new chemotherapeutic agents indicate a trend towards improved survival rates.

Docetaxel and gemcitabine combination therapy in advanced transitional cell carcinoma of the urothelium: results of a phase II and pharmacologic study

Our objective was to determine the response to gemcitabine plus docetaxel in advanced urothelial transitional cell carcinoma in a phase II trial, and gemcitabine distribution between plasma and erythrocytes, following docetaxel administration. Patients with locally advanced or metastatic transitional cell carcinoma, following a maximum of one prior chemotherapy regimen, were given gemcitabine 800 mg/m on days 1 and 8 plus docetaxel 85 mg/m on day 8, every 21 days. Gemcitabine was measured in the plasma and erythrocytes of nine patients before and after docetaxel administration. Thirty-four patients (median 63 years; range 49-79 years), of whom seven had prior chemotherapy and 27 were chemotherapy-naive, received a median of six cycles (range 1-6). Complete and partial remissions were observed in two and 16 (including three pretreated) patients, respectively, for an overall response rate of 53%. Median response duration was 5 months (range 1-39+). Haematoxicity was manageable, despite grade 3 infections in 24% of patients, but other toxicities were mostly mild. An apparent shift of gemcitabine from plasma to erythrocytes occurred after docetaxel in five of six patients evaluable for this analysis. We conclude gemcitabine plus docetaxel is tolerable and highly active in treated and untreated patients with advanced transitional cell carcinoma.

Phase II study of MTX-HSA in combination with Cisplatin as first line treatment in patients with advanced or metastatic transitional cell carcinoma

PURPOSE

To assess the efficacy, tolerability and safety of MTX-HSA (methotrexate (MTX) covalently linked to human serum albumin (HSA)) combined with cisplatin as first line therapy for advanced bladder cancer.

METHODS

Patients (pat) were treated with a loading dose of 110 mg/m(2) of MTX-HSA followed by a weekly dose of 40 mg/m(2) starting on day 8. Cisplatin was given on day 2 of each 28 day cycle at a dose of 75 mg/m(2).

RESULTS

Tumor response evaluation was possible in 7 patients. Complete response (CR) and partial response (PR) was observed in 1 patient each (overall response rate: 29%). Key toxicities included CTC Grade (G) 3/4 stomatitis in 6 patients, vomiting G3 in 1 patient, fatigue G3 in 1 patient and thrombocytopenia G3 in 3 patients.

CONCLUSION

The combination of MTX-HSA with cisplatin is feasible and shows antitumor activity against urothelial carcinomas combined with an acceptable toxicity profile.

Nested variant of urothelial carcinoma: A rare presentation

We report a rare presentation of a nested variant of urothelial carcinoma with liver and bone metastases in a 74-year-old man admitted to the hospital with bilateral hydronephrosis and acute renal failure. At cystoscopy, both ureters were obstructed, with the right ureter narrowed along its entire length. Subsequent histopathologic examination from the ureteral resection revealed nested variant of urothelial carcinoma. Bilateral stents were placed, and the patient survived 12 months with a good partial response to chemotherapy. A total of 76 cases of nested variant of urothelial carcinoma have been reported worldwide. Our patient was the first, to our knowledge, to present with bilateral hydronephrosis and tumor extension along one ureter.

Cyclooxygenase inhibitors in urinary bladder cancer:in vitroandin vivoeffects

More than 14,000 people die from invasive transitional cell carcinoma (TCC) of the urinary bladder yearly in the United States. Cyclooxygenase (COX)-inhibiting drugs are emerging as potential antitumor agents in TCC. The optimal in vitro or in vivo systems to investigate COX inhibitor antitumor effects have not been defined. The purpose of this study was to determine COX-1 and COX-2 expression and antitumor effects of COX inhibitors in human TCC cell lines (HT1376, RT4, and UMUC3 cells) and xenografts derived from those cell lines. COX-2 expression (Western blot, immunocytochemistry) was high in HT1376, modest in RT4, and absent in UMUC3 cells in vitro. Similarly, COX-2 expression was noted in RT4 but not UMUC3 xenografts. COX-2 expression in HT1376 xenografts was slightly lower than that observed in vitro. None of four COX inhibitors evaluated (celecoxib, piroxicam, valeryl salicylate, and NS398) reduced TCC growth in standard in vitro proliferation assays at concentrations that could be safely achieved in vivo (< or =5 micromol/L). Higher celecoxib concentrations (> or =50 micromol/L) inhibited proliferation and induced apoptosis in all three cell lines. Celecoxib or piroxicam treatment in athymic mice significantly delayed progression of HT1376 xenografts, which express COX-2, but not UMUC3 xenografts that lack COX-2 expression. In conclusion, standard in vitro assays were not useful in predicting COX inhibitor antitumor effects observed in vivo. Athymic mice bearing TCC xenografts provide a useful in vivo system for COX inhibitor studies. Results of this study provide justification for further evaluation of COX inhibitors as antitumor agents against TCC.

Pro-apoptotic effect of a nitric oxide-donating NSAID, NCX 4040, on bladder carcinoma cells

Nitric oxide-releasing non steroidal anti-inflammatory drugs (NO-NSAIDs) are a promising class of compounds that cause cell cycle perturbations and induce apoptosis in cell lines from different tumors. We investigated the activity of a recently developed NO-NSAID (NCX 4040) in bladder cancer cell lines (HT1376 and MCR). Cells were treated with different drug concentrations for different exposure times. Cytostatic and cytocidal activity was tested by SRB assay and apoptosis was evaluated by TUNEL analysis, ANNEXIN V assay and fluorescence microscopy. To further investigate the cell death-inducing mechanisms of NCX 4040, we analyzed gp-170, caspase expression and mitochondrial membrane potential (Delta Psi) depolarization. NCX 4040 showed a striking cytocidal activity in both cell lines, reaching LC(50) at a 10-microM and 50-microM concentrations in HT1376 and in MCR cells, respectively, after an exposure of only 6 h followed by an 18-h washout. Apoptosis was triggered in up to 90% of cells and was associated with active caspase-3 expression and Delta Psi depolarization in both cell lines after a 6-h exposure. In conclusion, NCX 4040, which probably causes apoptosis via a mitochondrial-dependent mechanism, could prove to be a useful agent for improving bladder cancer treatment.

Adjuvant and Neoadjuvant Chemotherapy in Muscle Invasive Bladder Cancer: Literature Review

Radical cystectomy is the standard treatment for patients with clinically localized muscle invasive bladder cancer, providing a 5-year survival rate of approximately 50%. Failure to cure is often due to the presence of occult metastases beyond the margins of local therapy, indicating a need for eradication of micrometastatic disease with systemic treatment, in order to improve survival. Combined chemotherapy regimens, such as methotrexate-vinblastine-cisplatin (CMV), methotrexate-vinblastine-cisplatin-doxorubicin (M-VAC) and gemcitabine-cisplatin (GC) have already demonstrated their effectiveness in patients with advanced or metastatic disease and have been considered as appropriate regimens in the peri-operative setting. Large randomized studies with a prolonged follow-up have been able to confirm a modest survival benefit with neoadjuvant therapy. A recent meta-analysis, including all previous reported randomized trials, concluded that neoadjuvant chemotherapy administration provides a significant survival benefit and can be administered without adverse outcomes resulting from delayed local therapy. Adjuvant chemotherapy trials, although promising, have failed to show statistically improved survival, mostly due to small sample sizes and absent or inconclusive data on overall survival. A multi-center randomized-controlled trial is currently ongoing, in order to elucidate the role of post-operative chemotherapy administration.

Twenty-three years of disease-free survival following cutaneous metastasis from a primary bladder transitional cell carcinoma

We present a case of cutaneous metastases from a primary bladder transitional cell carcinoma (TCC), with a prolonged survival of 23 years. Cutaneous metastases from primary bladder TCC are uncommon and, like all metastases, have a poor prognosis. The common modality of treatment of cutaneous metastases from a primary bladder cancer is wide local excision of the metastases followed by combination chemotherapy. Here, we present a case of a solitary cutaneous metastasis from a primary bladder TCC, which was treated with wide local excision and single agent chemotherapy. Twenty-three years on, the patient remains disease and recurrence free.

Kit (CD117) immunoreactivity is rare in renal cell and upper urinary tract transitional cell carcinomas

OBJECTIVE

To investigate the presence of Kit (CD117), a transmembrane tyrosinase-kinase receptor, in primary and metastatic renal cell carcinomas (RCCs) and upper urinary tract transitional cell carcinomas (TCCs).

MATERIALS AND METHODS

In human neoplasia, overexpression of Kit has been related to cell proliferation, differentiation, adhesion and control of apoptosis. If present, Kit may provide a suitable target for tumour therapy. Formalin-fixed and paraffin-embedded specimens of 180 primary and 58 metastatic RCCs and 54 upper urinary tract TCCs were immunostained for Kit (CD117) using a tissue microarray technique.

RESULTS

In RCCs, immunoreactivity for CD117 was detected in only two of 23 (9%) chromophobe tumours, whereas all 137 conventional and 20 papillary subtypes, and metastatic RCC tissues, lacked CD117 immunoreactivity. In TCCs, CD117 expression of <10% cancer cells was found in two of 53 (4%) cases. Stromal mast cells served as a positive control and showed specific immunostaining.

CONCLUSION

Kit immunoreactivity is infrequent in both RCCs and upper urinary tract TCCs. Thus, routine screening of tumour tissues for Kit by immunohistochemistry appears to be cost-ineffective and cannot be recommended. Moreover, the lack of substantial Kit immunoreactivity in both primary and metastatic carcinomas does not provide a rationale to investigate imatinib mesylate therapy in clinical trials including patients with advanced disease.

Gemcitabine and docetaxel as first-line treatment for advanced urothelial carcinoma: a phase II study

The purpose of the study was to investigate the toxicity and efficacy of the combination of gemcitabine and docetaxel in untreated advanced urothelial carcinoma. Patients with previously untreated, locally advanced/recurrent or metastatic urothelial carcinoma stage-IV disease were eligible. Patients with Performance status: PS ECOG >3 or age >75 years or creatinine clearance <50 ml min(-1) were excluded. Study treatment consisted of docetaxel 75 mg m(-2) (day 8) and gemcitabine 1000 mg m(-2) (days 1+8), every 21 days for a total of six to nine cycles. A total of 31 patients with urothelial bladder cancer, 25 men and six women, aged 42-74 (median 64) years were enrolled. The majority of patients had a good PS (51.6%; PS 0). In all, 15 (48.3%) patients had locally advanced or recurrent disease only and 16 (54.8%) presented with distant metastatic spread, with multiple site involvement in 22.5%. Toxicity was primarily haematologic, and the most frequent grade 3-4 toxicities were anaemia 11 (6.7%) thrombocytopenia eight (4.9%), and neutropenia 45 (27.6%), with 10 (6.1%) episodes of febrile neutropenia. No toxic deaths occurred. A number of patients had some cardiovascular morbidity (38.7%). Nonhaematological toxicities except alopecia (29 patients) were mild. Overall response rate was 51.6%, including four complete responses (12.9%) and 12 partial responses (38.7%), while a further five patients had disease stabilisation (s.d. 16.1%). The median time to progression was 8 months (95% CI 5.1-9.2 months) and the median overall survival was 15 months (95% CI 11.2-18.5 months), with 1-year survival rate of 60%. In conclusion, this schedule of gemcitabine and docetaxel is very active and well tolerated as a first-line treatment for advanced/relapsing or metastatic urothelial carcinoma. Although its relative efficacy and tolerance as compared to classic MVAC should be assessed in a phase III setting, the favourable toxicity profile of this regimen may offer an interesting alternative, particularly in patients with compromised renal function or cardiovascular disease.

Our experience with 23 consecutive patients on gemcitabine/carboplatin chemotherapy for treatment of metastasized transitional cell carcinoma of the urothelium

AIM

To evaluate the activity and toxicity of gemcitabine plus carboplatin in patients with metastatic transitional cell carcinoma (TCC) of the urothelium.

METHODS

Twenty-three consecutive patients (from February 1999 to January 2002) with metastatic TCC and no prior chemotherapy were referred to our institution. Each patient was treated with gemcitabine (1000 mg/m2) on Days 1 and 8 and carboplatin (area under curve, 4.5) on Day 1. Cycles were repeated every 21 days until tumor progression or severe toxicity was seen, or for a maximum of six cycles. Median age of the patients was 68 years (range 47-82). The median Eastern Cooperative Oncology Group (ECOG) performance score was one and the median creatinine clearance rate was 56 mL/min (range 31-94).

RESULTS

The overall response rate was 60.8%, with five of the 23 patients achieving a complete response, and nine showing a partial response. Median time to tumor progression (TTP) was 7.8 months, with a median survival of 15.4 months and a 1-year survival probability of 56%. Most of the complications from toxicity were hematological.

CONCLUSIONS

Gemcitabine plus carboplatin is active in the treatment of metastatic urothelial cancer in those patients new to chemotherapy and has an acceptable safety profile. The potential clinical benefit of this novel combination in the treatment of transitional cell carcinoma warrants further testing in Phase III studies.

Preclinical evaluation of a radiosensitizing effect of gemcitabine in p53 mutant and p53 wild type bladder cancer cells

OBJECTIVES

Despite clinical use, the radiosensitizing effect of gemcitabine (2'2'-difluorodeoxycytidine) in human transitional cell carcinoma (TCC) has not been shown to date. We investigated gemcitabine as a radiosensitizer for human TCC cells.

METHODS

Monolayer cultures of RT112 (G1, p53 wild type), RT4 (G1-G2, p53 wild type), T24 (G3, p53, mutant type), and SUP (G4, p53 mutant type) cells were incubated in medium with gemcitabine. Electron beam radiation was applied alone, simultaneous, or 3, 6, 12, and 24 hours after gemcitabine. Jurkat leukemia cells were used as controls for radiation toxicity. Cell survival was determined 6, 12, 24, 48, and 72 hours after radiation by microculture tetrazolium assay. DNA damage was evaluated by flow cytometric assessment of poly(ADP-ribose) polymerase, and apoptosis was determined by terminal-deoxynucleotidyltransferase-mediated dUTP nick-end labeling and flow cytometric assessment after annexin-V and propidium iodide labeling.

RESULTS

In all TCC cell lines, radiation alone caused only little and insignificant growth inhibitory effects at 10 Gy. Gemcitabine alone had a dose-dependent cytotoxic and apoptosis inducing effect on all TCC cell lines independent of p53 status. Assays combining radiation with gemcitabine in different dose and time schedules demonstrated no radiosensitizing effect in TCC cells.

CONCLUSIONS

Gemcitabine is effective in TCC cell lines independent of p53 status. A radiosensitizing effect could not be demonstrated. Again, p53 status was not predictive of the radioresponse in the bladder cancer cell lines. Clinical studies with gemcitabine and radiotherapy might nevertheless yield different results but should be performed with utmost caution.