Absence of p53 overexpression and favorable response to cisplatin-based neoadjuvant chemotherapy in urothelial carcinomas

Predictors of response to neoadjuvant therapy in urothelial cancer

Neoadjuvant cisplatin-based chemotherapy (NACC) followed by radical cystectomy is the standard treatment for localized muscle-invasive bladder cancer (MIBC). Patients who achieve a complete pathological response following NACC have better overall survival than those with residual disease. However, a subset of patients does not derive benefit from NACC while experiencing chemotherapy-related side effects that may delay cystectomy, which can be detrimental. There is a need for predictive and prognostic biomarkers to better stratify patients who will derive benefits from NACC. This review summarizes the currently available literature on various predictors of response to neoadjuvant chemotherapy. Covered predictors include clinical factors, treatment regimens (including chemotherapy and immunotherapy), histological predictors, and molecular predictors such as DNA repair genes, p53, FGFR3, ERBB2, Bcl-2, EMMPRIN, survivin, choline-phosphate cytidylyltransferase-α, epigenetic markers, immunological markers, other molecular predictors and gene expression profiling. Further, we elaborate on the potential role of neoadjuvant immunotherapy and the correlative biomarkers of response.

Near Complete Response to Platinum-based Systemic Chemotherapy in High-risk Upper Tract Urothelial Carcinoma With an ERBB2 Gene Mutation: A Case Report

In bladder urothelial carcinoma, ERBB2 mutations have been associated with favorable response to platinum-based neoadjuvant chemotherapy. However, this association has not been reported in upper tract urothelial carcinoma (UTUC). We describe an excellent response to cisplatin-based chemotherapy in metastatic UTUC with an ERBB2 mutation. Our patient is a 54-year-old female with metastatic UTUC who received systemic cisplatin and gemcitabine. Postchemotherapy imaging demonstrated decreased size of pyelocaliceal mass and decreased retroperitoneal adenopathy compared to initial imaging. Surgical pathology from consolidative resection showed 3 mm residual renal tumor and no viable lymph node disease. Genomic testing demonstrated an ERBB2 gain of function mutation.

The emerging role of somatic tumor sequencing in the treatment of urothelial cancer

The development of rapid genome sequencing has greatly enhanced our understanding of the molecular biology underlying many malignancies. Whole exome sequencing has highlighted the individualistic nature of malignancies on a patient-to-patient basis and begun to revolutionize therapeutic approaches. In recent years, whole genome sequencing of urothelial malignancies has identified a host of somatic mutations which contribute to growth, progression, and metastasis of urothelial carcinoma of the bladder and upper tract urothelial carcinoma. As genetic sequencing continues, additional targets will be identified, allowing development of novel therapeutic agents targeting cancer on a molecular level, with the goal of delivering highly individualized care based on the underlying mutational profile of the patient's malignancy. In this review, we aim to discuss known genetic alterations of urothelial malignancy and the implications these mutations carry in terms of prognostication and development of targeted therapeutic agents. We will focus on RNA-expression profiling and genomic DNA profiling, with a focus on comprehensive whole exome and whole genome sequencing relative to selected urothelial carcinoma-associated genes and circulating tumor DNA analysis.

Pharmacogenomic considerations in the treatment of muscle-invasive bladder cancer

Recent advances in next-generation sequencing techniques have greatly improved our understanding of the genomic alterations in bladder cancer. Cisplatin-based chemotherapy provides a viable treatment option in the neoadjuvant, adjuvant and metastatic setting in a selected group of patients, but chemoresistance is a major problem. The underlying mechanisms of treatment resistance are poorly understood and elucidating these pathways will subsequently lead to improved patient selection, less unnecessary drug-related toxicity, improved patient outcome and decreased healthcare costs. This review provides an overview of mechanisms of chemoresistance and describes the current knowledge on how the genomic landscape influences therapy outcome in muscle-invasive bladder cancer patients.

Molecular biomarkers to predict response to neoadjuvant chemotherapy for bladder cancer

Cystectomy is the gold standard for treatment of localized muscle-invasive bladder cancer. However, about 50% of patients develop metastases within 2years after cystectomy and subsequently die for the disease. Neoadjuvant cisplatin-based chemotherapy before cystectomy improves the overall survival in patients with muscle-invasive bladder cancer, and pathological response to neoadjuvant treatment (downstaging to ⩽pT1 at cystectomy) is a strong predictor of better disease-specific survival. Nevertheless, some patients do not benefit from neoadjuvant therapy. The identification of reliable biomarkers that could enable the clinicians to identify patients who will really benefit from neoadjuvant chemotherapy is a major issue. This approach could lead to individualized therapy, in order to optimize the chance of response, avoiding the impact of neoadjuvant treatment on quality of life and the delay of cystectomy in non-responder patients. However, no molecular predictive biomarkers have shown clinical utility. This paper aims to review currently available data about biomarkers predictive of response to neoadjuvant chemotherapy in muscle-invasive bladder cancer.

Accelerated methotrexate, vinblastine, doxorubicin, and cisplatin is safe, effective, and efficient neoadjuvant treatment for muscle-invasive bladder cancer: results of a multicenter phase II study with molecular correlates of response and toxicity

PURPOSE

Neoadjuvant cisplatin-based chemotherapy is standard of care for muscle-invasive bladder cancer (MIBC); however, it is infrequently adopted in practice because of concerns regarding toxicity and delay to cystectomy. We hypothesized that three cycles of neoadjuvant accelerated methotrexate, vinblastine, doxorubicin, and cisplatin (AMVAC) would be safe, shorten the time to surgery, and yield similar pathologic complete response (pT0) rates compared with historical controls.

PATIENTS AND METHODS

Patients with cT2-T4a and N0-N1 MIBC were eligible and received three cycles of AMVAC with pegfilgrastim followed by radical cystectomy with lymph node dissection. The primary end point was pT0 rate. Telomere length (TL) and p53 mutation status were correlated with response and toxicity.

RESULTS

Forty-four patients were accrued; 60% had stage III to IV disease; median age was 64 years. Forty patients were evaluable for response, with 15 (38%; 95% CI, 23% to 53%) showing pT0 at cystectomy, meeting the primary end point of the study. Another six patients (14%) were downstaged to non-muscle invasive disease. Most (82%) experienced only grade 1 to 2 treatment-related toxicities. There were no grade 3 or 4 renal toxicities and no treatment-related deaths. One patient developed metastases and thus did not undergo cystectomy; all others (n = 43) proceeded to cystectomy within 8 weeks after last chemotherapy administration. Median time from start of chemotherapy to cystectomy was 9.7 weeks. TL and p53 mutation did not predict response or toxicity.

CONCLUSION

AMVAC is well tolerated and results in similar pT0 rates with 6 weeks of treatment compared with standard 12-week regimens. Further analysis is ongoing to ascertain whether molecular alterations in tumor samples can predict response to chemotherapy.

The expression patterns of p53 and p16 and an analysis of a possible role of HPV in primary adenocarcinoma of the urinary bladder

BACKGROUND

Primary adenocarcinoma of the urinary bladder is rare. The molecular and cellular events leading to its pathogenesis are not well delineated. The goal of this study was to investigate p53 and p16 expression, as well as HPV status, in a relatively large series of primary bladder adenocarcinomas.

MATERIALS AND METHODS

Thirty six cases of urinary bladder adenocarcinoma were chosen from participating institutions. The diagnosis and available clinical history were reviewed in each case. Immunostains for p53, p16 and HPV and high-risk and low-risk HPV-ISH were performed on all tumors.

RESULTS

Patients had an average age of 61 years with a male predominance (1.5 ∶ 1 male ∶ female ratio). The average tumor size in cystectomy specimens was 4.3 cm. Of the cases managed by transurethral resection, 40% were pT2 at the time of diagnosis. In cystectomy specimens, 77% were either pT3 or pT4. Strong nuclear p16 expression was seen in 67% of all cases and p53 expression was present in 58% of the cases. Expression of both markers was seen in 33% of cases. Expression of p16 or p53 alone was present in 12 (33%) and 9 (25%) cases, respectively. Neither marker was expressed in only 3 (8%) of the tumors. No significant correlation between clinical variables and any of the markers we studied was identified. No HPV infection was detected in any case.

CONCLUSIONS

Expression of p53 and/or p16 is very common in urinary bladder adenocarcinoma. These findings implicate a high likelihood that alterations in these cell cycle proteins contribute to the pathogenesis of these tumors. Despite frequent immunohistochemical labeling for p16, no evidence of HPV infection was found.

Molecular determinants of response to cisplatin-based neoadjuvant chemotherapy

PURPOSE OF REVIEW

Neoadjuvant chemotherapy followed by cystectomy improves survival compared with surgery alone. To prevent overtreatment is of outmost importance to define molecular predictors of response for patient selection. We present the currently available data outlining a variety of potential markers to aid for a personalized decision-making process.

RECENT FINDINGS

Apart from p53, other markers of cell cycle regulation and apoptosis such as p21WAF1/CIP1 (p21) gene, Bcl-2, mouse double minute-2 and pRB have also been related to survival. The clinical relevance of epidermal growth factor receptor and HER2 expression has also been investigated with no success. Regarding Ki67, overexpressing tumors may potentially benefit from neoadjuvant therapy and conversely overexpression of vascular endothelial growth factor and bFGF have been linked to resistance to cisplatin-induced apoptosis. The role of multidrug resistance gene 1 and excision repair cross-complementing rodent repair deficiency complementation group 1 supports that enhanced DNA repair in the tumor decreases the benefit of platinum-based treatment. A 20-gene expression model has shown to predict lymph node involvement, helping on decision-making. A gene expression profiling has been proposed as predictive for response to neoadjuvant chemotherapy.

SUMMARY

Predictive markers will eventually aid in the selection of patients that most likely benefit from preoperative treatment. In the coming years, a panel of markers will become available to achieve the predicted goal.

Low ERCC1 expression is associated with prolonged survival in patients with bladder cancer receiving platinum-based neoadjuvant chemotherapy

PURPOSE

Excision repair cross-complementation group 1 enzyme (ERCC1) plays a key role in the removal of platinum induced DNA adducts and cisplatin resistance. Prognostic role of ERCC1 expression in the neoadjuvant setting in bladder cancer has not been reported before. We evaluated the prognostic role of ERCC1 expression in bladder cancer receiving platinum-based neoadjuvant chemotherapy.

MATERIALS AND METHODS

Thirty-eight patients with muscle invasive bladder cancer who received neoadjuvant platinum-based chemotherapy were included. Clinical and histopathologic parameters along with immunohistochemical ERCC1 staining were examined and correlated with response rates and survival.

RESULTS

Pathologic complete response rates were similar between patients with low and high ERCC1 expression. Median disease-free survival (DFS) was 9.3 vs. 20.5 months (P = 0.186) and median overall survival (OS) was 9.3 vs. 26.7 months (P = 0.058) in patients with high ERCC1 expression compared with those with low expression, respectively. In multivariate Cox regression analysis: pathological complete response (pCR) after chemotherapy (hazard ratio (HR) 0.1, 95% CI 0.012-0.842, P = 0.034) and high ERCC1 expression (HR 3.7, 95% CI 1.2-11.2, P = 0.019) were significantly associated with DFS. Patient age (>60 vs. ≤ 60 years) (HR 3.4, 95% CI 1.2-9.4, P = 0.018), the presence of pCR (HR 0.11, 95% CI 0.014-0.981, P = 0.048) and high ERCC expression (HR 6.1, 95 CI 1.9-19.9, P = 0.002) were significantly associated with OS.

CONCLUSIONS

Our results showed that high ERCC1 expression was independently associated with shorter disease-free and overall survival in patients with bladder cancer who received neoadjuvant platinum-based chemotherapy. ERCC1 may represent a potential predictive marker for platinum-based treatment in bladder cancer.

Assessing interactions between mdm-2, p53, and bcl-2 as prognostic variables in muscle-invasive bladder cancer treated with neo-adjuvant chemotherapy followed by locoregional surgical treatment

BACKGROUND

Tumor proliferation and apoptosis may be influenced by the mdm-2 gene product, which can block the antiproliferative effects of p53. bcl-2, one of a family of related genes that regulates the apoptotic pathway, exhibits a negative influence. Both individual and cooperative effects of these gene products may affect the biological behavior of primary bladder cancers and long-term outcome to standard therapy.

METHODS

This study retrospectively evaluated the association with survival of mdm-2, p53, and bcl-2 expression in 59 patients with muscle-invasive, node-negative transitional cell carcinoma (TCC) treated with neo-adjuvant chemotherapy followed by locoregional surgery. Each marker was defined as an altered phenotype if >or=20% malignant cells in the primary tumor exhibited staining; normal or minimal expression was defined as <20% cells exhibiting staining.

RESULTS

Altered mdm-2, p53, and bcl-2 expression was observed in 37%, 54%, and 46% of patients, respectively. In single marker analysis, altered p53 expression correlated with long-term survival (P = 0.05) but mdm-2 (P = 0.42) or bcl-2 (P = 0.17) did not. In the multiple-marker analysis, a prognostic index simultaneously assessing mdm-2, p53, and bcl-2 correlated with survival (P = 0.01). The 5-year survival for patients in which all markers were normally expressed was 54% compared with 25% in those with all three markers aberrantly expressed. Patients with aberrant expression of either one or two markers had an intermediate 5-year survival (49%). There was no association of molecular markers either alone or in combination with pathologic downstaging after neo-adjuvant chemotherapy.

CONCLUSION

The cooperative effects of phenotypes determined by mdm-2, p53, and bcl-2 expression may predict survival in patients with muscle-invasive TCC of the bladder.

Prognostic markers for bladder cancer: International Consensus Panel on bladder tumor markers

The International Consensus Panel on cytology and bladder tumor markers evaluated markers that have the ability to predict tumor recurrence, progression, development of metastases, or response to therapy or patient survival. This article summarizes those findings. The panel mainly reviewed articles listed in PubMed on various prognostic indicators for bladder cancer. Based on these studies, most of which were case-control retrospective studies, various prognostic indicators were classified into 6 groups: (1) microsatellite-associated markers, (2) proto-oncogenes/oncogenes, (3) tumor suppressor genes, (4) cell cycle regulators, (5) angiogenesis-related factors, and (6) extracellular matrix adhesion molecules. The panel concluded that although certain markers, such as Ki-67 and p53, appear to be promising in predicting recurrence and progression of bladder cancer, the data are still heterogeneous. The panel recommends that identifying definitive criteria for test positivity, a clearly defined patient population, standardization of techniques used to evaluate markers, and clearly specified endpoints and statistical methods will help to bring accurate independent prognostic indicators into the clinical management of patients with bladder cancer.

Antisense clusterin oligodeoxynucleotides increase the response of HER-2 gene amplified breast cancer cells to Trastuzumab

Clusterin (CLU) is a heterodimeric secreted glycoprotein implicated in several physiological and pathological processes including cancer. Although recent data showed that overexpression of CLU is closely associated with disease progression in patients with breast tumor, the functional role of CLU expression in this tumor hystotype remains to be determined. The objectives in this study were to evaluate CLU expression levels after treatment with Trastuzumab, a HER2-targeted monoclonal antibody used in the clinical management of advanced breast cancer patients, and to test the usefulness of combined treatment with OGX-011, the second generation 2'-methoxyethyl gapmer oligonucleotides targeting the CLU gene, and Trastuzumab in this tumor hystotype. By using the HER-2 gene amplified-BT474 human breast cancer cells, we found Trastuzumab decreased HER-2 expression and inhibited cell proliferation without affecting apoptosis. Interestingly, Trastuzumab treatment up-regulated CLU protein expression in a dose-dependent fashion. We therefore hypothesized that the treatment with OGX-011, by blocking Trastuzumab-induced CLU expression, might potentiate the growth-inhibitory effect of Trastuzumab alone. Although OGX-011 had no effect on the behavior of the BT474 cells when used alone, it significantly enhanced the sensitivity of cells to Trastuzumab. A significant increase in the percentage of apoptotic cells, analyzed in terms of annexin V positivity and cleavage of poly(ADP-ribose) polymerase, was observed after combined treatment with OGX-011 plus Trastuzumab but not with either agent alone. Altogether our findings suggest that combined targeting of HER-2 and CLU may represent a novel, rational approach to breast cancer therapy.

Clinical evaluation of serum p53 antibodies in patients with upper urinary tract tumors

PURPOSE

We retrospectively assessed the clinical significance of anti-p53 antibody (S-p53Ab) status in the serum of patients with upper urinary tract tumors.

MATERIALS AND METHODS

Enzyme-linked immunosorbent assay was used to analyze S-p53Abs in 63 upper urinary tract tumors. Its incidence and clinical or pathological background were analyzed in comparison with 80 bladder tumors.

RESULTS

The prevalence of S-p53Abs in patients with upper urinary tract tumors was higher than that in patients with bladder tumors (27.0% vs 17.5%). Especially, 34.8% of patients showed positive S-p53Abs in invasive upper urinary tract tumors (pT1 or more). In upper urinary tract tumors the prevalence of S-p53Abs significantly correlated with higher grade (p <0.01), higher stage (p = 0.02), positive lymph nodes (p = 0.03) and p53 nuclear accumulation (p <0.01). However, disease specific survival after nephroureterectomy did not differ between patients with negative and positive S-p53Abs.

CONCLUSIONS

Our data suggest the possibility of the clinical application of S-p53Abs, especially for the detection of high grade or high stage tumors in the upper urinary tract. However, the usefulness of S-p53Abs as prognostic marker seems to be extremely limited in patients with urothelial tumors.

Therapeutic efficacy of adenoviral-mediated p53 gene transfer is synergistically enhanced by combined use of antisense oligodeoxynucleotide targeting clusterin gene in a human bladder cancer model

To establish a more effective therapeutic strategy against advanced bladder cancer, we investigated the effects of combined treatment with antisense (AS) oligodeoxynucleotide (ODN) targeting the anti-apoptotic gene clusterin and adenoviral-mediated p53 gene transfer (Ad5CMV-p53) using the human bladder cancer KoTCC-1 model. Clusterin expression in KoTCC-1 cells was highly upregulated by Ad5CMV-p53 treatment; however, AS clusterin ODN treatment further suppressed clusterin expression in KoTCC-1 cells after Ad5CMV-p53 treatment. AS clusterin ODN treatment synergistically enhanced the cytotoxic effect of Ad5CMV-p53, and DNA fragmentation characteristic of apoptosis was observed only after combined treatment with AS clusterin ODN and Ad5CMV-p53, but not after treatment with either agent alone. Administration of AS clusterin ODN and Ad5CMV-p53 into nude mice resulted in a significant inhibition of KoTCC-1 tumor growth as well as lymph node metastases compared to administration of either agent alone. Furthermore, combined treatment with AS clusterin ODN, Ad5CMV-p53, and cisplatin completely eradicated KoTCC-1 tumors and lymph node metastases in 60% and 100% of mice, respectively. These findings suggest that combined treatment with AS clusterin ODN and Ad5CMV-p53 could be a novel strategy to inhibit bladder cancer progression, and that further additional use of a chemotherapeutic agent may substantially enhance the efficacy of this combined regimen.

Synergistic antitumor activity by combined treatment with gemcitabine and antisense oligodeoxynucleotide targeting clusterin gene in an intravesical administration model against human bladder cancer kotcc-1 cells

PURPOSE

We investigated whether antisense (AS) oligodeoxynucleotide (ODN) targeting the clusterin gene enhances the cytotoxic effect of gemcitabine in human bladder cancer KoTCC-1 cells in vitro and in vivo, and evaluated the usefulness of the combined administration of AS clusterin ODN and gemcitabine using an intraperitoneal tumor cell injection model.

MATERIALS AND METHODS

The cytotoxic effect of combined treatment with AS clusterin ODN and gemcitabine on in vitro KoTCC-1 growth was examined using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The in vivo growth inhibitory effects of combined AS clusterin ODN and gemcitabine therapy on subcutaneous KoTCC-1 tumor was also examined. The intraperitoneal tumor cell injection model, which mimics intravesical administration therapy against bladder cancer, was used to evaluate the efficacy of combined AS clusterin ODN and gemcitabine therapy.

RESULTS

AS clusterin ODN treatment of KoTCC-1 cells significantly enhanced gemcitabine chemosensitivity in a dose dependent manner, decreasing gemcitabine IC50 by approximately 90%. In vivo systemic administration of AS clusterin ODN and gemcitabine significantly decreased subcutaneous KoTCC-1 tumor volume compared with scramble control ODN plus gemcitabine. Furthermore, combined administration of AS clusterin ODN plus gemcitabine resulted in significantly delayed formation of hemorrhagic ascites compared with scramble control ODN plus gemcitabine in an intraperitoneal tumor cell injection model.

CONCLUSIONS

These findings suggest that AS clusterin ODN may be useful for enhancing the cytotoxicity of gemcitabine in patients with bladder cancer, particularly as a novel therapeutic strategy for intravesical instillation therapy.

Clinical evaluation of p53 mutations in urothelial carcinoma by IHC and FASAY

OBJECTIVES

To assess the clinical benefit of the methods of detection of p53 mutations in human urothelial carcinoma.

METHODS

A total of 75 surgical specimens of urothelial carcinoma were analyzed using a yeast functional assay (FASAY) and immunohistochemistry (IHC), in combination with sequencing analysis.

RESULTS

Of the 75 specimens, 24 (32.0%) were positive (mutant) by FASAY and 23 (30.7%) were positive by IHC. The sequencing analysis confirmed that all 24 FASAY-positive tumors harbored mutations, and no mutations were detected in any FASAY-negative tumors. In contrast, nuclear accumulation of p53 protein was detected in 9 (17.6%) of 51 tumors with no mutation, and 10 (41.7%) of 24 tumors with mutation showed no positive staining on IHC. The mutations detected by FASAY and IHC were both associated with stage and grade, but null mutations of p53 were not associated with stage. Concerning chemosensitivity, 6 (85.7%) of 7 responders harbored p53 missense mutations in at least one allele (P = 0.01), and only 4 (57.1%) were judged positive by IHC (P = 0.13).

CONCLUSIONS

FASAY is more accurate than IHC in detecting the various types of p53 mutations, suggesting that a comprehensive approach for the detection of p53 mutations may be essential to elucidate their clinical significance.

The prevalence and clinicopathologic correlate of p16INK4a, retinoblastoma and p53 immunoreactivity in locally advanced urinary bladder cancer

The purpose of the study was to investigate the prognostic value and clinicopathological correlate of tumor p53, p16 and Rb protein expression in patients with locally advanced urinary bladder cancer. Sixty-five patients (44 men and 21 women; 40 to 84 yrs old) with locally advanced urinary bladder cancer (21 pT2, 27pT3, 17pT4) undergoing radical cystectomy and bilateral pelvic lymph node dissection were followed up for 2 to 116 months (mean +/- SD: 30.02 +/- 6.46 months). Immunohistochemical staining for p53, Rb and p16 proteins were performed on surgically obtained, formalin fixed and paraffin embedded tissue sections. Thirty of the tumors (46.2%) were p53+, 52 of the tumors (80%) were p16- and 41 (63%) were Rb-. Only 5 of the tumors (7.7%) had normal expression of all three proteins. The tumor expression status of p53 could not be correlated with p16 (P = 1.000) or Rb (P = 1.000). Only a marginal inverse relationship was found between the expression of p16 and Rb (P = 0.056). Higher grade tumors had significantly lower percentage of p16 abnormality (P = 0.05), while higher grade (not higher stage) tumors had higher percentage of Rb abnormality (P = 0.0245). Univariate analysis showed that tumor expression of Rb or p16, alone or combined, had no predictive value on progression-free and disease-specific survival. It did, however, show a significant correlation between progression-free survival and tumor p53 and LN status (P = 0.032 and P = 0.0304) and a significant correlation between tumor stage disease-specific survival (P = 0.042). Multivariate analysis showed tumor stage and nodal status to be two significant independent indicators for progression-free survival (P = 0.0038 and P = 0.0049) and disease-specific survival (P = 0.0066 and P = 0.0484). It was also noteworthy that, after receiving postoperative adjuvant systemic M-VEC chemotherapy, patients with node-positive p53-normal tumors had significantly better progression-free and disease-specific survivals than those with node-positive p53-abnormal tumors (P = 0.036 and P = 0.0479, respectively). This study has found tumor expression of p53, p16 and Rb proteins in locally advanced bladder cancer to be frequently abnormal. Although multivariate analysis showed tumor stage and nodal status to be the only two statistically significant parameters, p53 may also serve as an additional prognostic predictor of the outcome of postoperative adjuvant systemic chemotherapy in patients with regional lymph node tumor involvement. Such patients with p53-normal tumors experienced significantly better progression-free and disease-specific survivals than those with p53-abnormal tumors.

[Perspectives for molecular diagnostics exemplified by urothelial bladder carcinoma]

The rapidly growing knowledge of molecular mechanisms will change the daily routine of clinicians in the near future. Regarding urothelial bladder carcinoma, one may expect that molecular diagnostics will identify patients susceptible to disease development by screening their genotype. Furthermore, in addition to histopathologic findings, prognostic markers will be used for disease management. In an ongoing multicenter trial, the decision on whether or not to treat patients with adjuvant chemotherapy after cystectomy is based on their p53 status. In the near future, cytostatic medications are expected to be chosen according to genetic profiles of the tumor or patient. New medications, which target tumor-specific alterations of cell-signaling cascades in bladder or other cancers, prominently inhibitors of the ERBB membrane receptor family, are currently under clinical investigation and will undoubtedly form an important part of therapeutic oncologic regimens. In conclusion, evaluation of gene profiles of tumors and patients will gain importance for clinicians.

Overexpression of clusterin in transitional cell carcinoma of the bladder is related to disease progression and recurrence

OBJECTIVES

To determine whether the expression level of clusterin in transitional cell carcinoma (TCC) of the bladder could be used as a predictor of tumor recurrence and prognosis.

METHODS

Total RNA samples were extracted from 89 specimens of TCC of the bladder, and the expression level of clusterin mRNA in these specimens was measured by Northern blot analysis. The results were evaluated with respect to several clinicopathologic factors.

RESULTS

The mean level of clusterin mRNA expression in invasive TCC of the bladder was fourfold and fivefold higher than that in superficial TCC and normal urothelial tissue, respectively. The expression level of clusterin mRNA showed no significant correlation with sex, age, tumor size, or multiplicity, and the pathologic stage and tumor grade showed close associations with clusterin expression. The overall survival rate of patients with strong clusterin expression was significantly lower than that of patients with weak expression. Among the 43 patients with invasive TCC who underwent complete resection, the recurrence-free survival rate of patients with strong clusterin expression was significantly lower than that of patients with weak expression. Moreover, multivariate analyses indicated that among these 43 patients, strong expression of clusterin was an independent predictor of tumor recurrence. CONCLUSIONS. These findings indicate that clusterin mRNA is strongly expressed in invasive TCC of the bladder compared with the expression in superficial TCC and that strong clusterin expression could be used as a novel predictor of prognosis of patients with TCC of the bladder.

p53 immunohistochemistry in bladder cancer. Combined analysis: a way to go?

Seven years after the initial reports of the potential prognostic value of p53 immunohistochemistry in bladder cancer, key questions remain unanswered. This is mainly due to conflicting results obtained through multiple retrospective trials mostly performed with small numbers of poorly defined patients. The aim of this article was to investigate the feasibility of a combined analysis of previously published data. Based on a MEDLINE search in 1997, papers reporting on the prognostic role of p53 alterations were identified and the respective groups were invited to participate. Twenty-six of 38 study centers approached contributed patient data sets according to the protocol requirements. Acceptance of the initiative was similar in Europe, North America, and Australasia. A total of 3,421 patients with bladder cancer from 25 centers are included in the further analysis. With regard to gender, age distribution, and tumor stage the patients contributed are comparable with a normal bladder cancer population. Considering tumor grade, G2 tumors appear to be over- represented while the amount of G1 tumors is smaller than expected. The reason for this is probably related to the low rate of p53 accumulation in G1 tumors. No significant differences between those groups initially approached and those that finally cooperated were noted. Therefore, it is concluded that a combined study is feasible, and the patient data collected are representative for the population presented in the published literature. The final analysis of the data is the subject of current investigation.

Synergistic chemosensitization and inhibition of tumor growth and metastasis by adenovirus-mediated P53 gene transfer in human bladder cancer model

OBJECTIVES

To determine whether an adenovirus-mediated p53 gene (Ad5CMV-p53) transfer enhances cisplatin cytotoxicity in vitro and whether Ad5CMV-p53 and cisplatin synergistically inhibit growth and metastasis in vivo using human bladder cancer KoTCC-1 cells.

METHODS

MTT assays and DNA fragmentation assays were used to examine the effects of treatment with Ad5CMV-p53 and/or cisplatin on growth inhibition and induction of apoptosis, respectively, in KoTCC-1 cells. The efficacies of combined Ad5CMV-p53 and/or cisplatin therapy against growth and metastasis of KoTCC-1 tumors were assessed using subcutaneous and orthotopic tumor cell injection models.

RESULTS

Ad5CMV-p53 substantially enhanced cisplatin chemosensitivity in a dose-dependent manner, reducing the median IC(50) by more than 50%. Characteristic apoptotic DNA laddering was induced by the combination of sublethal doses of Ad5CMV-p53 and cisplatin, but not by either agent alone. Furthermore, combined Ad5CMV-p53 and cisplatin therapy synergistically inhibited growth of subcutaneous KoTCC-1 tumors and the incidence of metastasis after orthotopic injection.

CONCLUSIONS

These findings illustrate that combined treatment with Ad5CMV-p53 and cisplatin could be an attractive strategy for inhibiting progression of bladder cancer through effective induction of apoptosis.

Phase I/II study of paclitaxel, carboplatin, and methotrexate in advanced transitional cell carcinoma: a well-tolerated regimen with activity independent of p53 mutation

OBJECTIVES

To evaluate the feasibility and activity of paclitaxel, carboplatin, and methotrexate in advanced transitional cell carcinoma (TCC) of the urothelium and to relate the activity of this combination to the mutational status of p53.

METHODS

In the Phase I portion, paclitaxel 200 mg/m(2) (3-hour infusion), carboplatin dosed to an area under the curve (AUC) of 6 mg/mL. min, and methotrexate 10 mg/m(2), increasing in 10-mg/m(2) increments, were administered on day 1 and every 21 days thereafter with granulocyte colony-stimulating factor (G-CSF) and leucovorin support. Subsequently, a Phase II study was initiated in which the carboplatin dose was lowered to an AUC of 5 to allow treatment without G-CSF. p53 expression was evaluated using immunohistochemistry.

RESULTS

Thirty-three patients were accrued. Median age was 66 years. No dose-limiting toxicities were seen in the Phase I portion despite escalation of the methotrexate to 60 mg/m(2). Principal toxicities were myelosuppression and neuropathy. The overall response rate (Phase I and II) was 56% (95% confidence interval 38% to 74%). Median survival was 15.5 months; 88% of patients overexpressed p53 at the primary site.

CONCLUSIONS

Paclitaxel, carboplatin, and methotrexate were well tolerated and active in advanced TCC. The high response rate to this regimen despite frequent p53 mutation is consistent with the p53-independent mechanism of paclitaxel. Whether this regimen is superior to methotrexate/vinblastine/doxorubicin/cisplatin, other paclitaxel-based regimens, or to paclitaxel alone will require comparative trials.

Negative p53/positive p21 immunostaining is a predictor of favorable response to chemotherapy in patients with locally advanced bladder cancer

The relationship between clinical response to DNA-damaging drugs and p53 and p21 status in patients with locally advanced transitional cell carcinoma (TCC) of the bladder was assessed. The response to intraarterial chemotherapy (IAC) comprising 100 mg / m(2) of cisplatin (CDDP) and 40 mg / m(2) of pirarubicin (THP) and the prognosis were assessed in 23 patients (the mean follow-up period was 19 months). The p53 gene status of tumors was analyzed at exons 5 - 8 using polymerase chain reaction-single strand conformation polymorphism analysis in 19 patients, and paraffin-embedded tumor sections were immunostained for p53 and p21 in 23 patients. The overall objective response rate (incidence of good responders) was 70%. The negative p53 group (n = 17) showed a significantly higher objective response rate than the positive p53 group (n = 6) (82% vs. 33%; P = 0.045). The p53 gene status or p21 staining status was not significantly associated with responsiveness. When the p53 and p21 immunostaining results were combined, good responders were more accurately predicted than by p53 staining status alone; the negative p53 / positive p21 group (n = 12) showed an objective response rate of 92%, which was significantly higher than that of the positive p53 and / or negative p21 group (45%, n = 11) (P = 0.027). Cause-specific survival of the negative p53 group was significantly superior to that of the positive p53 group (P = 0.015). Negative p53 / positive p21 immunostaining is a possible predictor of favorable chemotherapeutic response in patients with TCC of the bladder.

A critical analysis of the use of p53 as a marker for management of bladder cancer

Delineating the important molecular pathways in carcinogenesis has helped develop and advance the field of molecular diagnosis. Bladder cancer has served as an excellent model in translating some of the advances from the laboratory to clinical settings. Many investigators have examined the use of p53 to help manage patients with bladder cancer who are at high risk of tumor progression. This article reviews the clinical studies that have used p53 as a marker in bladder carcinoma and concludes by determining whether routine assessment of the p53 tumor suppressor gene/protein is indicated at this time.

Synergistic enhancement of resistance to cisplatin in human bladder cancer cells by overexpression of mutant-type p53 and Bcl-2

PURPOSE

The objective of this study was to characterize the effect of mutant-type p53 and Bcl-2 expression on the sensitivity to cisplatin in a human bladder cancer cell line both in vitro and in vivo.

MATERIALS AND METHODS

We transfected mutant-type p53 cDNA, Bcl-2 cDNA, or both cDNAs into KoTCC-1, a human bladder cancer cell line that does not express mutant-type p53 or Bcl-2 protein. The effects of the overexpression of mutant-type p53, Bcl-2, or both on the sensitivity to cisplatin and the apoptotic features in vitro were evaluated by the MTT assay, staining with Hoechst 33258 and a DNA fragmentation assay. We then examined the in vivo effects of cisplatin treatment on the transfectants by subcutaneous and intraperitoneal tumor cell injection models in athymic nude mice.

RESULTS

The introduction of mutant-type p53 or Bcl-2 conferred resistance to cisplatin on KoTCC-1 cells through the inhibition of apoptosis. This phenotype was more remarkable in the cell line transfected with both mutant-type p53 and Bcl-2 than in the cell lines transfected with either mutant-type p53 or Bcl-2 alone. Furthermore, the KoTCC-1 cells transfected with both mutant-type p53 and Bcl-2 exhibited significantly higher resistance to cisplatin treatment than cells transfected with mutant-type p53 or Bcl-2 alone in experimental models in vivo.

CONCLUSIONS

These findings suggest that the overexpression of both mutant-type p53 and Bcl-2 in bladder cancer cells synergistically interferes with the therapeutic effect of cisplatin through the inhibition of the apoptotic pathway.