Frequent p16/MTS1 inactivation in early stages of urothelial carcinoma of the bladder is not associated with tumor recurrence

Companied P16 genetic and protein status together providing useful information on the clinical outcome of urinary bladder cancer

SPEC P16/CEN3/7/17 Probe fluorescence-in-situ-hybridization (FISH) has become the most sensitive method in indentifying the urothelial tumors and loss of P16 has often been identified in low-grade urothelial lesions; however, little is known about the significations of other P16 genetic status (normal and amplification) in bladder cancer.We detected P16 gene status by FISH in 259 urine samples and divided these samples into 3 groups: 1, normal P16; 2, loss of P16; and 3, amplified P16. Meanwhile, p16 protein expression was measured by immunocytochemistry and we characterized the clinicopathologic features of cases with P16 gene status.Loss of P16 occurred in 26.2%, P16 amplification occurred in 41.3% and P16 gene normal occurred in 32.4% of all cases. P16 genetic status was significantly associated with tumor grade and primary tumor status (P = .008 and .017), but not with pathological tumor stage, overall survival, and p16 protein expression. However, P16 gene amplification accompanied protein high-expression has shorter overall survival compared with the overall patients (P = .023), and P16 gene loss accompanied loss of protein also had the tendency to predict bad prognosis (P = .067).Studies show that the genetic status of P16 has a close relation with the stages of bladder cancer. Loss of P16 is associated with low-grade urothelial malignancy while amplified P16 donotes high-grade. Neither P16 gene status nor p16 protein expression alone is an independent predictor of urothelial bladder carcinoma, but combine gene and protein status together providing useful information on the clinical outcome of these patients.

p16/Ki-67 dual labeling and urinary cytology results according to the New Paris System for Reporting Urinary Cytology: Impact of extended follow-up

BACKGROUND

Overexpression of p16^INK4a has been identified in urothelial malignancies both cytologically and histologically. In addition, p16/Ki-67 dual labeling has been shown to identify high-grade urothelial cancer cells and some progression cases within a 12-month delay. The Paris System for Reporting Urinary Cytology (TPS) was published in late 2015. Its aim is to clarify the criteria for diagnosing or, conversely, excluding high-grade urothelial carcinoma (HGUC).

METHODS

Dual labeling was performed on archived ThinPrep-based Papanicolaou slides. A total of 208 samples (negative for high-grade urothelial carcinoma [NHGUC], 59; consistent with low-grade urothelial neoplasia [LGUN], 24; atypical urothelial cells [AUC], 15; and suspicious for or showing HGUC, 110) were analyzed for p16/Ki-67 after reclassification according to TPS. We assessed the oncologic status of the patients with cystoscopy, urinary cytology, histology, and prolonged 36-month follow-up data.

RESULTS

The sensitivity of p16/Ki-67 for life-threatening lesions was not different from that of urinary cytology (82.8% vs 83.6%; P = 1). However, among patients with samples classified as NHGUC and AUC, disease-free survival was significantly shorter for dual-labeled cases versus cases with negative dual labeling (P < .0001). The same tendency was observed in patients with histologically proven LGUN (P < .0001). As for specificity in patients with negative cystoscopy and cytology combined, prolonged follow-up showed 90% overall survival at 24 months.

CONCLUSIONS

A long-term evaluation of p16/Ki-67 dual labeling may identify HGUC and progression in cases with negative/low-grade urinary cytology results, and there are potential implications for the clinical management of patients after the conservative treatment of non-muscle-invasive urothelial carcinoma. Cancer Cytopathol 2017;125:552-62. © 2017 American Cancer Society.

Prognostic and Clinicopathological Significance of Downregulated p16 Expression in Patients with Bladder Cancer: A Systematic Review and Meta-Analysis

p16, encoded by the CDKN2A gene, is a tumor suppressor that has been widely studied in cancer research. However, the relationship of p16 with prognostic and clinicopathological parameters in patients with bladder cancer remains unclear. Data inclusion criteria were articles reporting on the relationship between p16 expression and the prognosis or clinicopathology in patients with bladder cancer. Meta-analyses were performed with Stata software. Hazard ratios (HRs) or odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated to evaluate the relative risks. The source of heterogeneity was analyzed by subgroup analysis. A total of 37 studies with 2246 cases were included and analyzed. The results identified an important link between downregulated p16 expression and poor prognosis in patients with bladder cancer in terms of recurrence-free survival (RFS), overall survival (OS), progression-free survival (PFS), and some clinicopathological parameters including clinical staging, pathological degree, and lymph node metastasis. Subgroup analysis also showed that low p16 expression could function as a warning sign for RFS and PFS in patients with early-stage (Ta–T1) bladder cancer. In conclusion, p16 might play an essential role in the deterioration of bladder cancer and could serve as a biomarker for the prediction for patients' progression and prognosis.

p16(INK4a) overexpression is not linked to oncogenic human papillomaviruses in patients with high-grade urothelial cancer cells

BACKGROUND

p16(INK4a) Is overexpressed in almost all precancerous and carcinomatous lesions of the uterine cervix, secondary to interference between high-risk human papillomaviruses (hr-HPVs) and the retinoblastoma gene product. Overexpression of p16(INK4a) has also been identified in patients with high-grade urothelial lesions, both cytologically and histologically. However, the etiological role of HPV has not been documented except in inverted papillomas, low-grade bladder tumors, and younger patients. We therefore attempted to verify if HPV DNA was detectable in p16(INK4a) -positive urothelial tumors.

METHODS

A total of 90 urinary cytology samples (33 negative/low-grade cases and 57 high-grade proliferations) were analyzed for p16(INK4a) and HPV DNA. HPV genotyping was performed by polymerase chain reaction using a low-density DNA microarray enabling the detection of 35 HPVs. A reasoned approach combining tissue genotyping and in situ hybridization (ISH) for hr-HPVs was used in patients with urinary HPV.

RESULTS

Low-risk HPV (HPV-84) and hr-HPVs (HPV-16, -31, and -70) were detected. The prevalence of hr-HPVs in the urine was low: 5 of 82 patients (6.1%) and only 4 of 50 patients (8.0%) with high-grade urothelial malignancy. p16(INK4a) overexpression was noted in 49 high-grade samples (85.9%). In patients with p16(INK4a) -positive tumor cells and hr-HPV in the urine, HPV genotyping and ISH for hr-HPVs were negative in matched tissue sections.

CONCLUSIONS

Our study shows a low prevalence of hr-HPVs in the urine of patients with high-grade urothelial malignancy. In those, p16(INK4a) overexpression occurs in the absence of demonstrable HPV DNA in the tissue sections, contrary to what is noted in gynecopathology.

Genotyping of high-risk human papillomaviruses in p16/Ki-67-positive urothelial carcinoma cells: even a worm will turn

OBJECTIVE

Co-expression of p16INK4a protein and Ki-67 (p16/Ki-67) is noted in almost all high-grade urothelial lesions. However, the aetiological role or, conversely, the absence of causative effect of high-risk human papillomaviruses (hr-HPVs) has not been documented. The purpose of this study is to evaluate HPV DNA in p16/Ki-67-positive, high-grade urothelial tumour cells.

METHODS

Fifty-seven urine samples collected from 50 patients, including 55 histologically proven high-grade proliferations and two cases with clinical evidence of malignancy, were analysed for p16/Ki-67. Immunolabelling was performed in destained Papanicolaou-stained slides after ThinPrep(®) processing. HPV genotyping was performed by polymerase chain reaction (PCR) using a DNA microarray for 35 HPV types. Confirmation of the presence (or absence) of HPV in tissue samples was verified using a reasoned approach combining PCR and in situ hybridization (ISH) for hr-HPVs.

RESULTS

Co-expression of p16/Ki-67 was noted in 43 of 57 (75.4%) cases. In these, hr-HPVs 16, 31 and 70, and low risk HPV 84, were detected in the urine in four patients (8%). Upregulation of p16INK4a protein was confirmed on bladder biopsy or transurethral resection specimens, but PCR and ISH for hr-HPVs were both negative on the tissue sections.

CONCLUSION

Our results show a low prevalence of HPV infection in the urinary tract of patients with p16/Ki-67-positive urothelial malignancy. The study confirms that the deregulated cell cycle, as demonstrated by p16/Ki-67 dual labelling, is independent of the oncogenic action of hr-HPVs in high-grade urothelial proliferations.

p16 INK4a overexpression and p16/Ki-67 dual labeling versus conventional urinary cytology in the evaluation of urothelial carcinoma

BACKGROUND

Taking into consideration the known overexpression of p16(INK4a) in histologically demonstrated high-grade urothelial malignancies, the objective of the current study was to examine the value of p16(INK4a) overexpression and of p16/Ki-67 dual labeling versus urinary cytology in the detection of urothelial lesions.

METHODS

Immunolabeling was performed on demounted and destained Papanicolaou slides after liquid-based ThinPrep processing. Actual diagnoses were ascertained by cystoscopy controls and histopathology. Negative cases, papillary urothelial neoplasia of low malignant potential/low-grade tumor, and high-grade lesions were considered separately.

RESULTS

A total of 216 urine samples were collected from new patients with symptoms who were referred for cystoscopy (92 cases) or patients who were being followed after conservative treatment for lesions involving the bladder (117 cases) or the upper urinary tract (7 cases). p16(INK4a) positivity was assessed in 171 of the 216 cases (79.2%) and in 93 of 99 high-grade cases with positive cytology (93.9%). Coexpression of p16/Ki-67 in the same cells was observed in 119 of 216 cases (55.1%) and was noted in 18 of 51 cases of negative or papillary urothelial neoplasia of low malignant potential/low-grade tumor (35.3%) and in 80 of 101 high-grade tumors (79.2%) (P < .0001). Thirteen of 14 high-grade intraurothelial lesions (92.8%) were dual labeled. When high-grade tumors, disease progression (increased grade, muscle infiltration, and extension into the upper urinary tract), and cancer-related death were grouped together as an endpoint, dual labeling demonstrated a sensitivity that was slightly higher than that of urinary cytology (82.5% vs 80.8%; P = .8), with 94.9% overall specificity.

CONCLUSIONS

When applied to the search for high-grade and aggressive disease, p16/Ki-67 dual labeling and urinary cytology appear to demonstrate comparable performance.

Biomarkers in bladder cancer: translational and clinical implications

Bladder cancer is associated with high recurrence and mortality rates. These tumors show vast heterogeneity reflected by diverse morphologic manifestations and various molecular alterations associated with these disease phenotypes. Biomarkers that prospectively evaluate disease aggressiveness, progression risk, probability of recurrence and overall prognosis would improve patient care. Integration of molecular markers with conventional pathologic staging of bladder cancers may refine clinical decision making for the selection of adjuvant and salvage therapy. In the past decade, numerous bladder cancer biomarkers have been identified, including various tumor suppressor genes, oncogenes, growth factors, growth factor receptors, hormone receptors, proliferation and apoptosis markers, cell adhesion molecules, stromal factors, and oncoproteins. Recognition of two distinct pathways for urothelial carcinogenesis represents a major advance in the understanding and management of this disease. Nomograms for combining results from multiple biomarkers have been proposed to increase the accuracy of clinical predictions. The scope of this review is to summarize the major biomarker findings that may have translational and clinical implications.

Aberrant protein expression and promoter methylation of p16 gene are correlated with malignant transformation of salivary pleomorphic adenoma

CONTEXT

The significance of promoter methylation of the p16 gene and intracellular localization of p16 protein in the carcinogenesis of salivary carcinoma ex pleomorphic adenoma (Ca-ex-PA) is not clear. The correlation of the promoter methylation of the p16 gene and the expression and localization of p16 protein in Ca-ex-PA need to be further clarified.

OBJECTIVE

To investigate the p16 protein expression and promoter methylation of p16 gene in Ca-ex-PA and their roles in the malignant transformation of pleomorphic adenoma to Ca-ex-PA.

DESIGN

The p16 protein expression and promoter methylation of the p16 gene were determined in both benign and malignant components of 50 primary salivary Ca-ex-PA tissues by immunohistochemistry and methylation-specific polymerase chain reaction. Expression of p16 protein and promoter methylation of the p16 gene between the benign and the malignant components was compared statistically.

RESULTS

The tumor cells in the malignant components showed significantly higher p16 protein expression in the cytoplasm and lower expression in the nuclei than those in the benign components. Promoter methylation frequency of the p16 gene in the malignant components (36%) was significantly higher than that in the benign components (16%). There were no correlations between p16 protein expression and promoter methylation of the p16 gene in either benign or malignant components.

CONCLUSIONS

Overexpression of p16 protein in the cytoplasm and decreased expression of p16 protein in the nucleus may play important roles in the evolution of pleomorphic adenoma to Ca-ex-PA. Promoter methylation of the p16 gene may be correlated with the malignant transformation of pleomorphic adenoma.

Prognostic value of loss of heterozygosity at chromosome 9p in non-muscle-invasive bladder cancer

OBJECTIVE

To investigate the prognostic value of loss of heterozygosity (LOH) at chromosome 9p in patients with non-muscle-invasive bladder cancer (NMI-BC).

METHODS

Between 2000 and 2006, we included in the study 84 patients with NMI-BC. LOH analyses were performed on tumor tissue using 3 microsatellite markers at chromosome 9p. Associations of LOH with recurrence and progression of the tumors were evaluated.

RESULTS

Frequency of LOH at 9p was 11.1%, 29.0%, and 31.6% in pTaG1, pTaG2, and pT1G3 tumors, respectively. Recurrence occurred in 27 patients. None of the markers was able to predict recurrence. Progression occurred in 9.5% of the cases, with progression to muscle-invasive bladder cancer (MI-BC) in 4.8% of the cases. LOH at IFN-alpha was significantly associated with progression to MI-BC (P = .006). In the case of LOH at IFN-alpha, 2-year progression-free survival and progression-free survival to MI-BC were both 59.3%, compared with 97.1% and 98.6%, respectively, in case of conservation of LOH in multivariable analysis, LOH at IFN-alpha remained statistically associated with progression and progression to MI-BC. LOH at IFN-alpha was a significant and independent predicting factor of progression and progression to MI-BC, with P = .05 and 0.01 (HR 4.8 for progression; HR 24.2 for muscle invasion).

CONCLUSIONS

Our study suggests that LOH at IFN-alpha is an independent prognostic factor for progression to MI-BC. LOH analysis of bladder tumors may help in the management of NMI-BC. Specifically, it could be of use in selecting patients for early aggressive treatment and/or in planning close follow-up schedule.

Biomarkers in bladder cancer

Cancer biomarkers provide an opportunity to diagnose tumours earlier and with greater accuracy. They can also identify those patients most at risk of disease recurrence and predict which tumours will respond to different therapeutic approaches. Such biomarkers will be especially useful in the diagnosis and management of bladder cancer. At present, bladder tumours are diagnosed and followed-up using a combination of cystoscopic examination, cytology and histology. These are not only expensive, but also highly subjective investigations and reveal little about the underlying molecular characteristics of the tumour. In recent years numerous diagnostic and prognostic biomarkers of bladder cancer have been identified. Two separate approaches to biomarker discovery have been employed. The first is hypothesis-driven and focuses upon proteins involved in molecular pathways known to be implicated in tumorigenesis. An alternative approach has been to study the global expression of genes (so-called 'genomics') looking for characteristic signatures associated with disease outcomes. In this review we summarize the current state of biomarker development in this field, and examine why so few have made the successful transition into the clinic. Finally, we introduce a novel approach to biomarker development utilizing components of the DNA replication licensing machinery.

Molecular genesis of non-muscle-invasive urothelial carcinoma (NMIUC)

Urothelial carcinoma (UC) is the most common type of bladder cancer in Western nations. Most patients present with the non-muscle-invasive (NMIUC) form of the disease, while up to a third harbour the invasive form (MIUC). Specifically, the aetiology of NMIUC appears to be multifactorial and very different from that of MIUC. Loss of specific tumour suppressor genes as well as gain-of-function mutations in proteins within defined cellular signalling pathways have been implicated in NMIUC aetiology. The regions of chromosome 9 that harbour CDKN2A, CDKN2B, TSC1, PTCH1 and DBC1 are frequently mutated in NMIUC, resulting in functional loss; in addition, HRAS and FGFR3, which are both proto-oncogenes encoding components of the Ras-MAPK signalling pathway, have been found to harbour activating mutations in a large number of NMIUCs. Interestingly, some of these molecular events are mutually exclusive, suggesting functional equivalence. Since several of these driving changes are amenable to therapeutic targeting, understanding the signalling events in NMIUC may offer novel approaches to manage the recurrence and progression of this disease.

p16(INK4a) expression analysis as an ancillary tool for cytologic diagnosis of urothelial carcinoma

We immunochemically studied p16(INK4a) expression in 116 urine cytologic samples and compared results with 190 histologic samples. The cytologic samples were classified into 4 groups: 1, mild cellular atypia; 2, moderate cellular atypia; 3, severe cellular atypia; and 4, malignancy. Overexpression of p16(INK4a) was detected in none of 32 cases in group 1, 8 (16%) of 50 cases in group 2, 5 (42%) of 12 cases in group 3, and 11 (50%) of 22 cases in group 4. In addition, by histologic analysis, p16(INK4a) overexpression was not detected in nonneoplastic urothelium, except for a few cases of reactive atypia, but it was detected in about 50% of urothelial carcinomas. In particular, a high incidence (16/20 [80%]) of p16(INK4a) overexpression in high-grade carcinomas was noted in cytologic samples. Immunocytologic analysis of p16(INK4a) expression in cytologic samples is a useful ancillary tool for detection of urothelial carcinoma with infiltrating potential.

Specific 50'CpG island methylation signatures of FHIT and p16 genes and their potential diagnostic relevance in Indian breast cancer patients

Even after tremendous molecular studies, early detection,more accurate and sensitive diagnosis, and prognosis of breast cancer appear to be a riddle so far. To stab the enigma, this study is designed to envisage DNA methylation signatures as cancer-specific and stage-specific biomarkers in Indian patients. Rigorous review of scattered scientific reports on aberrant DNA methylation helped us to select and analyze a potential tumor suppressor gene pair (FHIT and p16 genes) in breast cancer patients. Methylation signatures from 232 primary sporadic breast cancer patients were pinpointed by methylation-specific PCR (MSP). To increase the sensitivity, we combined both MSP and expression studies (RT-PCR and Northern blotting) in a reproducible manner. Statistical analysis illustrated that hypermethylation of FHIT gene ( p < 0.0001) and p16 gene ( p=0.04) may be used as a potential diagnostic marker to diagnose the early and locally advanced stages of breast cancer. Additionally, the study authenticates the dependency of methylation and expressional loss of p16 gene on FHIT gene silencing. This observation not only describes the severity of disease when both genes are silenced but also drives to speculate the molecular cross talk between two genes or genetic pathways dictated by them separately.

Loss of P16 expression and chromosome 9p21 LOH in predicting outcome of patients affected by superficial bladder cancer

OBJECTIVES

To evaluate the prognostic role of p16 expression and loss of heterozygosity (LOH) on chromosome 9p21 in patients affected by low-grade (G1-G2) urothelial bladder cancer.

METHODS

Fifty-six consecutive patients with diagnosis of urothelial bladder cancer were enrolled in this prospective study. LOH analysis was performed on a blood/tumor pair sample of each patient, by using polymerase chain reaction analysis. The D9S171 (9p21) locus on chromosome 9 was investigated. All tumors were stained immunohistochemically for p16. Data from p16 and LOH analyses were compared with follow-up data to evaluate the prognostic role of these molecular markers.

RESULTS

Loss of p16 expression was found in 33 patients (58.9%) and was significantly associated with the reduced recurrence-free probability (P < 0.0001). No correlations were reported with stage (P = 0.162) or grade (P = 0.051). Forty-three patients (76.7%) showed LOH on chromosome 9p21 (D9S171). A significant association was observed between loss of p16 expression and LOH on chromosome 9p21 (P = 0.005). The Kaplan-Meier curves showed a significant correlation between recurrence-free status and p16 expression (P = 0.0001). By multivariate analysis, p16 expression (P = 0.002) and number of lesions (P = 0.002) were identified as independent tumor recurrence factors.

CONCLUSIONS

Our study highlights the prognostic role of p16 in predicting the recurrence-free probability in patients affected by low-grade urothelial bladder and highlights the fact that this method could be used in everyday urologic clinical practice to better characterize the natural history of urothelial bladder carcinomas.

False-positive lesions detected by fluorescence cystoscopy: any association with p53 and p16 expression?

To determine p53 and p16 status as molecular markers of bladder cancer, in histologically proven benign bladder biopsies, obtained from lesions suspect for malignancy as judged by fluorescence cystoscopy. Immunohistochemical (IHC) staining was performed for p53 and p16, using the antibodies DO-7 and AB-4, respectively. The tissue sections were scored in percentages of nuclear staining for p53 and p16. Of 247 biopsies, 41/49 lesions appeared suspicious on fluorescence cystoscopy, but were histopathologically benign. 2/40 (5%) were > or =20% p53 positive as compared to 7/128 (5.5%) of all histopathologically benign biopsies. 24/37 (64.9%) were p16 negative (<5% positive cells) as compared to 84/125 (67.2%) of all benign biopsies. Most biopsies had a moderate to high degree of chronic cystitis. False positive lesions of fluorescence cystoscopy did not differ from benign lesions detected by standard white light cystoscopy with regard to p53 and p16 immunoreactivity. Little evidence remains for these lesions to be pre-malignant.

Immunohistochemical analysis for cell regulatory proteins in bladder carcinogenesis induced by N-methyl-N-nitrosourea-terephthalic acid

To explore the cell cycle regulatory mechanism in bladder carcinogenesis promoted by terephthalic acid calculi (TPA-calculi), male Wistar rats were initiated with N-methyl-N-nitrosourea (MNU) (20mg/kg b.w. i.p.) twice a week for 4 weeks, and then given basal diet containing 5% TPA, 5% TPA plus 4% Sodium bicarbonate (NaHCO(3)) or 1% TPA for the next 22 weeks. Major regulatory proteins in G1 cell cycle checkpoint including p16(INK4a), cyclin-dependent kinase 4 (Cdk4), cyclin D(1), retinoblastoma protein (pRb) were determined during various stages of urinary bladder carcinogenesis by using immunohistochemistry. In MNU-5% TPA treated group, the incidences of overexpression of Cdk4, cyclin D(1) and pRb in papilloma were significantly higher than these in simple hyperplasia (p=0.023, p<0.001 and 0.001, respectively) and in PN hyperplasia (p=0.042, 0.012 and 0.002, respectively). The incidence of absent expression of p16(INK4a) in papilloma was much higher than that in simple hyperplasia (p=0.004) and in PN hyperplasia (p=0.02). Our results clearly reveal that the deregulation of p16(INK4a)-cyclin D(1)/Cdk4-pRb pathway is associated with bladder carcinogenesis promoted by TPA-calculi.

Transitional cell bladder tumor: predicting recurrence and progression by analysis of microsatellite loss of heterozygosity in urine sediment and tumor tissue

Transitional cell bladder tumors (TCT) is prone to recurrence (60-80%) after tumor resection. Up to 25% of these patients will progress, so it is important to find reliable predictive markers. We analyzed for loss of heterozygosity (LOH) with respect to 13 microsatellites located on 10 different chromosomal arms. This analysis was performed on the urine sediment and tumor tissue from 59 patients with bladder TCT and on the urine and normal-looking mucosa from 25 patients with a history of bladder TCT but no evidence of disease at the time of the study inclusion. The median follow-up period was 23.1 months (range, 2-48 months) for the 59 patients with bladder TCT and 25 months (range, 4-57 months) for the 25 patients without evidence of ongoing active disease. Correlation between LOH and eventual recurrence, progression, and mortality was investigated. In patients with noninvasive TCT, correlation between 11p tumor tissue LOH and recurrence was found. Similarly, 8p LOH in both urine sediment and tumor tissue correlated with progression. Finally, in the group of patients with a history of bladder TCT, normal tissue 8p and/or 11p LOH correlated with recurrence.

Molecular and immunohistochemical analysis of the prognostic value of cell-cycle regulators in urothelial neoplasms of the bladder

OBJECTIVE

To evaluate the prognostic and predictive value of molecular and immunohistochemical markers related to cell-cycle control in terms of recurrence, progression, and survival in urothelial neoplasms of the bladder (UNB).

PATIENTS AND METHODS

Clinical and pathological findings of 84 patients with UNB were assessed. Homozygous deletion (HD) and promoter methylation of p14ARF, p15INK4B, p16INK4A, loss of heterozygosity of the locus 9p21, p53 mutations, and immunohistochemical expression of p53, p16, p14, p21, p27, pRb, Ki67, MDM2, and cyclin D1 proteins were evaluated in relation to overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS).

RESULTS

In the univariate analysis, RFS was shorter in cases with p14ARF (p=0.006), p15INK4B (p=0.003), p16INK4A (p=0.03) HD, low p14 immunoreactivity index (IRI) (p=0.01) and high Ki67 IRI (p=0.04); HD of the 9p21 locus genes and p14 IRI remained as independent prognostic factors for early UNB recurrence (p=0.006) whereas tumour stage (p=0.00001) and cyclin D1 IRI (p=0.049) were related to worse PFS in the multivariate analysis. In the univariate analysis, IRI for Ki67 (p=0.002), cyclin D1 (p=0.06), p53 (p=0.00008), p16 (p=0.02), p27 (p=0.0005) MDM2 (p=0.01) and p53 mutations (p=0.03) were related to poor OS, and only the Ki67 IRI retained their independent value in the multivariate analysis.

CONCLUSION

9p21 HD and p14 IRI constitute independent predictive factors for UNB recurrence and cyclin D1 IRI and tumour stage for progression. In addition, Ki67 IRI and tumour stage are independent prognostic factors for overall survival in UNB.

Expresión inmunohistoquímica de p53, p21, p16 y Ciclina D1 en el cáncer de vejiga superficial. Estudio en un soporte de tissue microarray

INTRODUCTION AND OBJECTIVES

To retrospectively assess the relationship between immunohistochemical expression of p53, p21, p16, and cyclin D1, with recurrence, progression and survival in superficial bladder cancer.

METHODS

163 patients undergoing transurethral resection for superficial bladder cancer between February 1995 and March 2004. Tumor samples were included in a tissue microarray support that was serially sectioned for immunohistochemical staining. Grade and stage associations for each marker were evaluated by the Chi-square test. Assessment of the relationship with recurrence, progression, and survival Kaplan-Meier curves and log-rank test were used.

RESULTS

There were no statistically significant differences in marker expression depending on tumor grade and stage, with the exception of Cyclin D1, that was significantly different depending on tumor stage (p=0.030). p21 expression was related to tumor recurrence (p=0.035), progression (p=0.008) and survival (p=0.034). p16 expression was also related to recurrence (p=0.048) and survival (p=0.047), but not to tumor progression (p=0.116). p53 and Cyclin D1 were not statistically associated with tumor recurrence, progression or survival.

CONCLUSIONS

In our experience, only p16 and p21 may be useful in the management of superficial bladder tumors, as they are predictors of recurrence and survival in Ta and T1 patients.

Measurement of relative copy number of CDKN2A/ARF and CDKN2B in bladder cancer by real-time quantitative PCR and multiplex ligation-dependent probe amplification

Many tumors have large homozygous deletions of the CDKN2A locus (encoding p14(ARF) and p16) and of CDKN2B (p15). Our aim was to determine which gene is the major target in bladder cancer. We used quantitative real-time PCR (RTQ-PCR) to determine copy number of p15, of p14(ARF) exon 1beta, and p16 exon 2 in 22 tumor cell lines and 83 bladder tumors, some of which had been assessed previously by duplex PCR. Titration experiments showed that homozygous deletion could be detected in the presence of up to 30% normal DNA. Results for cell lines were compatible with previous cytogenetic analyses. Ten cell lines and 32 tumors (38.5%) had homozygous deletion of at least one target. Thirteen tumors (15.7%) had deletion of all three targets. Two tumors had deletion of p14(ARF) exon 1beta alone and four of p16 exon 2 alone. RTQ-PCR detected more homozygous deletions than duplex PCR. Finally we used a multiplex ligation-dependent probe amplification kit to provide independent confirmation of results. We conclude that with appropriate controls RTQ-PCR is a sensitive and robust method to detect copy number changes in tumors even in the presence of contaminating normal cell DNA.

Bladder epithelial cell proliferation of rats induced by terephthalic acid-calculi

OBJECTIVE

Urinary bladder hyperplasia associated with terephthalic acid (TPA) treatment was examined with concomitant use of sodium bicarbonate (NaHCO3) or hydrochlorothiazide to allow assessment of the relationship among bladder stones, epithelial hyperplasia, and corresponding cell cycle checkpoint gene expression in Sprague-Dawley (SD) rat.

METHODS

A total of 112 weanling male SD rats that divided between six groups were given basal diet (control), diets containing 5% TPA or in combination with either 4% sodium NaHCO3 or 0.02% hydrochlorothiazide. After 90-day feeding, bladder samples were collected for histopathological diagnoses, and immunohistochemical method was used to characterize the expression of p16Ink4a cyclin D1, CDK4, EGFr and cyclin E in relation to that of proliferating cell nuclear antigen (PCNA).

RESULTS

In TPA treatment groups, bladder stone incidence was 40% (21/52) with 14 cases of proliferative bladder. In control and other groups, neither stone nor epithelial cell proliferation was diagnosed. PCNA-positive focal hyperplasic lesions involved all epithelial layers. Overexpressions of cyclin D1, CDK4, EGFr are found in the corresponding lesion. p16Ink4a nuclear staining reduced in proliferative bladders especially with a great quantity of stone. In addition, no positive expression was detected on cyclin E.

CONCLUSION

The present study provides a strong evidence of a link between induction of bladder hyperplasia, deregulation of the p16Ink4a-cyclin D1/CDK4 pathway, and abnormal EGFr mediated signal transduction pathway.

P16 immunoreactivity is an independent predictor of tumor progression in minimally invasive urothelial bladder carcinoma

OBJECTIVE

To evaluate the prognostic impact of p16 immunoreactivity in minimally invasive transitional cell bladder carcinomas (stage T1).

METHODS

Multi-tissue-arrays containing 73 samples of T1 bladder carcinomas were stained immunohistochemically for p16. Additionally, p53 and Ki-67 antigen expression were examined. A multivariate analysis including other prognostically relevant factors like tumor grade and sub-stage was performed.

RESULTS

Loss of p16 expression occurred in 54% of cases and was significantly associated with reduced progression-free (p=0.018 by univariate analysis), but not with recurrence-free survival (p=0.341). Median Ki-67 antigen and p53 index were 51% (range, 1-93%) and 10% (range, 0-100%), respectively. Both indices correlated significantly (p=0.041 and p=0.024, respectively) with recurrence-free, but not with progression-free survival. Also tumor grade was significantly associated with tumor recurrence (p=0.006). By multivariate analysis, tumor grade (p=0.008) was identified as an independent predictor of tumor recurrence, whereas p16 expression (p=0.009) was identified as an independent predictor of tumor progression.

CONCLUSION

According to our data, there is a significant correlation between loss of p16 expression and tumor progression in patients with minimally-invasive bladder cancer. Immunohistochemical p16 staining may therefore represent a useful tool of providing additional information on the clinical outcome of these patients.

Prediction of progression in pTa and pT1 bladder carcinomas with p53, p16 and pRb

Currently available prognostic tools appear unable to adequately predict recurrence and progression in non muscle-invasive bladder carcinomas. We aimed to assess the prognostic value of immunohistochemical evaluation of the cell cycle markers p53, p16 and pRb. Paraffin blocks were obtained from 78 cases of pTa and pT1 transitional cell carcinomas, for which long-term follow-up was available. Representative sections were stained using antibodies against p53, p16 and pRb. Altered marker expression was found in 45, 17 and 30% of cases, respectively. Concurrent alteration of two or three markers occurred in 19% of cases, and was significantly associated with grade and stage. In univariate survival analysis, the concurrent alteration of any two markers was significantly associated with progression. The greatest risk was produced by alteration of both p53 and p16, which increased the risk of progression by 14.45 times (95% confidence interval (CI) 3.10–67.35). After adjusting for grade and stage, this risk was 7.73 (CI 1.13–52.70). The markers did not generally predict tumour recurrence, except in the 25 pT1 tumours. In these, p16 alteration was associated with a univariate risk of 2.83 (CI 1.01–7.91), and concurrent p53 and p16 alteration with a risk of 9.29 (CI 1.24–69.50). Overall, we conclude that the immunohistochemical evaluation of p53 and p16 may have independent prognostic value for disease progression, and may help guide management decisions in these tumours.

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.

Expression of cell cycle proteins in T1a and T1b urothelial bladder carcinoma and their value in predicting tumor progression

BACKGROUND

Cell cycle proteins are important markers in predicting tumor behavior in urothelial carcinoma of the bladder. The objectives of this study were 1) to determine the expression levels of some of those markers in a series of patients with bladder carcinoma, 2) to define their value in distinguishing T1a (minimally invasive) from T1b (invasive) tumors, and 3) to evaluate their use as predictive factors in the progression of T1a and T1b tumors.

METHODS

Tumor specimens from 101 patients were included (22 Ta specimens, 34 T1a specimens, 15 T1b specimens, and 30 T2 specimens). A tissue microarray from the 101 paraffin embedded tissue blocks was constructed. Immunohistochemistry for p16, p27, p21, p53, cyclin D1, and Ki-67 were performed. To evaluate T1a and T1b tumor progression, clinical and follow-up data were available for all 49 patients.

RESULTS

Cyclin D1 and p27 were the only markers that showed a significant association with tumor stage and tumor grade (cyclin D1: P = 0.002 and P > 0.00, respectively; p27: P = 0.024 and P = 0.031, respectively). The results indicated that a combination of p21 (odds ratio, 5.7; 95% confidence interval [95% CI], 1.3-24.8 [P = 0.022]) and p16 (odds ratio, 3.7; 95% CI, 0.8-16.5 [P = 0.081]) may have potential use in distinguishing T1b tumors from T1a tumors. Finally, none of the markers examined were found to have predictive value for T1a and T1b tumor progression.

CONCLUSIONS

The expression of cyclin D1 and p27 was associated with the most important prognostic factors (tumor stage and grade). The combination of p21 and p16 may have value in distinguishing T1b tumors from T1a tumors, although this finding must be evaluated in much larger series. Finally, none of the markers studied appeared to have predictive value for disease progression in patients with T1a and T1b urothelial bladder tumors.

Prognostic value of MCM2 immunoreactivity in stage T1 transitional cell carcinoma of the bladder

OBJECTIVE

Due to the heterogeneous biologic behavior of stage T1 bladder carcinomas, there is a need for new markers allowing to assess the prognosis more accurately. To our knowledge, there are no reports on studies investigating minichromosome maintenance protein 2 (MCM2) expression in bladder carcinomas. Thus, we investigated the prognostic value of MCM2 immunoreactivity in stage T1 bladder tumors.

METHODS

Fifty-four tumors were analyzed using Biochip microarrays. Also p53 and Ki67 antigen expression were examined. Immunohistochemical scores were compared with the clinical outcome.

RESULTS

During a median follow-up of 43 months, tumor recurrence was registered in 43 and progression to stage T2 in 19 patients. Kaplan-Meier curves demonstrated that high-level MCM2 expression was significantly associated with early tumor recurrence when using a cutoff of 60% (p=0.0035 by log-rank test), and with early tumor progression when using a cutoff of 20% (p=0.0454). There was no relationship (p=0.604) between MCM2 and p53, but a tendentious relationship (p=0.082) between MCM2 and Ki67 antigen expression. MCM2 (p=0.006), Ki67 antigen (p=0.035) and p53 expression (p=0.049) as well as tumor grade (p=0.026) and age (p=0.025) were found significantly associated with recurrence-free survival by univariate Cox regression analysis, among which only Ki67 antigen expression (p=0.015) and age (p=0.019) proved to be of independent predictive value by multivariate analysis. Concerning tumor progression, MCM2 expression was identified as the only predictive parameter by log-rank test, but it was not of independent predictive value by multivariate analysis (p=0.101).

CONCLUSION

Our data suggest that MCM2 expression may bear some prognostic relevance in stage T1 bladder carcinomas.