Combination of CK20 and Ki-67 immunostaining analysis predicts recurrence, progression, and cancer-specific survival in pT1 urothelial bladder cancer

Immunohistochemical Differentiation between Urothelial Papillomas and Papillary Neoplasms of Low Malignant Potential of the Urinary Bladder

BACKGROUND

Urothelial papilloma and non-invasive papillary carcinoma are common neoplasms of the urinary bladder. Distinguishing papillomas and papillary carcinomas, especially the low grade type, is often debatable on the basis of histological features alone.

MATERIALS AND METHODS

We investigated immunohistochemical expression of cytokeratin 20 (CK20), p53, and Ki-67 in a group of 20 urothelial papilloma cases and 30 noninvasive papillary neoplasms of low malignant potential (PNLMP) of the urinary bladder. Whole tissue sections were examined.

RESULTS

Among the 30 carcinoma cases, 12 (40%) showed strong reactivity for the whole panel, 16 (53%) reacted positively for two markers, and 2 (7%) reacted just to one of them. Ki-67 was considered positive in 27 cases (90%) and p53 in 24 (80%), CK20 showed positive reactivity in 21 cases (70%). Only small percentages of papillomas were positive, and then only weakly.

CONCLUSIONS

We concluded that the intense positivity of suspicious cells for at least one of these markers would confirm the presence of malignant changes and favours the diagnosis of carcinoma.

High Ki-67 Immunohistochemical Reactivity Correlates With Poor Prognosis in Bladder Carcinoma: A Comprehensive Meta-Analysis with 13,053 Patients Involved

Ki-67 is considered as one of prime biomarkers to reflect cell proliferation and immunohistochemical Ki-67 staining has been widely applied in clinical pathology. To solve the widespread controversy whether Ki-67 reactivity significantly predicts clinical prognosis of bladder carcinoma (BC), we performed a comprehensive meta-analysis by combining results from different literature. A comprehensive search was conducted in the Chinese databases of WanFang, China National Knowledge Infrastructure and Chinese VIP as well as English databases of PubMed, ISI web of science, EMBASE, Science Direct, and Wiley online library. Independent studies linking Ki-67 to cancer-specific survival (CSS), disease-free survival (DFS), overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS) were included in our meta-analysis. With the cut-off values literature provided, hazard ratio (HR) values between the survival distributions were extracted and later combined with STATA 12.0. In total, 76 studies (n = 13,053 patients) were eligible for the meta-analysis. It was indicated in either univariate or multivariate analysis for survival that high Ki-67 reactivity significantly predicted poor prognosis. In the univariate analysis, the combined HR for CSS, DFS, OS, PFS, and RFS were 2.588 (95% confidence interval [CI]: 1.623-4.127, P < 0.001), 2.697 (95%CI: 1.874-3.883, P < 0.001), 2.649 (95%CI: 1.632-4.300, P < 0.001), 3.506 (95%CI: 2.231-5.508, P < 0.001), and 1.792 (95%CI: 1.409-2.279, P < 0.001), respectively. The pooled HR of multivariate analysis for CSS, DFS, OS, PFS, and RFS were 1.868 (95%CI: 1.343-2.597, P < 0.001), 2.626 (95%CI: 2.089-3.301, P < 0.001), 1.104 (95%CI: 1.008-1.209, P = 0.032), 1.518 (95%CI: 1.299-1.773, P < 0.001), and 1.294 (95%CI: 1.203-1.392, P < 0.001), respectively. Subgroup analysis of univariate analysis by origin showed that Ki-67 reactivity significantly correlated with all 5 clinical outcome in Asian and European-American patients (P < 0.05). For multivariate analysis, however, the pooled results were only significant for DFS, OS, and RFS in Asian patients, for CSS, DFS, PFS, and RFS in European-American patients (P < 0.05). In the subgroup with low cut-off value (<20%), our meta-analysis indicated that high Ki-67 reactivity was significantly correlated with worsened CSS, DFS, OS, PFS, and RFS on univariate analysis (P < 0.05). For multivariate analysis, the meta-analysis of literature with low cut-off value (<20%) demonstrated that high Ki-67 reactivity predicted shorter DFS, PFS, and RFS in BC patients (P < 0.05). In the subgroup analysis of high cut-off value (≥20%), our meta-analysis indicated that high Ki-67 reactivity, in either univariate or multivariate analysis, significantly correlated with all five clinical outcomes in BC patients (P < 0.05). The meta-analysis indicates that high Ki-67 reactivity significantly correlates with deteriorated clinical outcomes in BC patients and that Ki-67 can be considered as an independent indicator for the prognosis by the meta-analyses of multivariate analysis.

[Molecular classification of bladder cancer. Possible similarities to breast cancer]

Therapeutic decisions for breast cancer are increasingly becoming based on subtype-specific gene expression tests. For bladder cancer very similar subtypes have been identified by genome-wide mRNA analysis, which as for breast cancer differ with respect to the prognosis and response to therapy on the basis of their hormone dependency. At the DNA level, however, the type of mutations and their frequencies within the subtypes are strikingly different between bladder and breast cancers. It will be interesting to see whether possible driver mutations can serve as therapeutic targets in both indications. In contrast, the apparent hormone dependency of a substantial number of bladder carcinomas suggests that hormonal and anti-hormonal treatment can be valid therapy options similar to breast cancer. Moreover, gender-specific differences with respect to the incidence and aggressiveness of male compared to female bladder cancers can be explained by hormonal effects. Together with forthcoming immunomodulatory therapies these multiple therapy options raise and give new hope to efficiently combat this aggressive disease.

Prostate tumor overexpressed 1 expression in invasive urothelial carcinoma

PURPOSE

To determine the expression patterns of the proliferation marker prostate tumor overexpressed 1 (PTOV1) in invasive urothelial cancer (UC).

METHODS

Corresponding UC and benign samples from paraffin-embedded tissue of 102 patients treated with cystectomy for invasive UC were immunohistochemically (IHC) assessed for PTOV1. Expression was evaluated gradually separated for cytoplasmic and nuclear staining. Results were correlated to histological and clinical data. To correlate PTOV1 expression with molecular subtypes of UC, analysis of PTOV1 RNA expression data of the Cancer Genome Atlas UC cohort was performed.

RESULTS

PTOV1 expression was present in UC and benign urothelium, whereby nuclear staining was significantly more frequent in UC tissue (p = 0.0004). Lower cytoplasmic expression was significantly associated with pathological stage >pT2 (p = 0.0014) and grade ≥G3 (p = 0.0041), respectively. IHC expression patterns did not show correlation to survival data. PTOV1 RNA expression correlated with features of the luminal UC subtype.

CONCLUSIONS

Subcellular distribution seems to be the most important feature of PTOV1 expression in UC. Nuclear localization of PTOV1 along with cytoplasmic decrease in PTOV1 expression was identified as putative surrogate for PTOV1-associated cellular proliferation and dedifferentiation in UC. The functional relevance as well as the potential role of PTOV1 as a biomarker in UC remains to be specified in future studies.

Treatment of non-muscle invasive bladder cancer with Bacillus Calmette-Guerin (BCG): Biological markers and simulation studies

Intravesical Bacillus Calmette-Guerin (BCG) vaccine is the preferred first line treatment for non-muscle invasive bladder carcinoma (NMIBC) in order to prevent recurrence and progression of cancer. There is ongoing need for the rational selection of i) BCG dose, ii) frequency of BCG administration along with iii) synergistic adjuvant therapy and iv) a reliable set of biochemical markers relevant to tumor response. In this review we evaluate cellular and molecular markers pertinent to the immunological response triggered by the BCG instillation and respective mathematical models of the treatment. Specific examples of markers include diverse immune cells, genetic polymorphisms, miRNAs, epigenetics, immunohistochemistry and molecular biology 'beacons' as exemplified by cell surface proteins, cytokines, signaling proteins and enzymes. We identified tumor associated macrophages (TAMs), human leukocyte antigen (HLA) class I, a combination of Ki-67/CK20, IL-2, IL-8 and IL-6/IL-10 ratio as the most promising markers for both pre-BCG and post-BCG treatment suitable for the simulation studies. The intricate and patient-specific nature of these data warrants the use of powerful multi-parametral mathematical methods in combination with molecular/cellular biology insight and clinical input.

Invasive low-grade papillary urothelial carcinoma: an immunohistochemical study of 26 cases

Invasive low-grade papillary urothelial carcinoma (LGPUC) is rare. We studied the immunohistochemical (IHC) expressions of CK20, p53, E-cadherin, phosphatase and tension homolog (PTEN), and Ki-67 in both noninvasive and invasive components in 26 cases. In the noninvasive component of LGPUC, 81% showed CK20 expression, and 50% showed p53 labeling. There was a wide range of Ki-67 labeling from less than 5% to 70%. All cases had intact PTEN except 1 that showed focal clonal PTEN loss in both noninvasive and subjacent invasive components. All cases had preserved strong and diffuse E-cadherin expression in both noninvasive and invasive components. There was no significant change between the noninvasive and invasive components in the IHC labeling of these markers, although 7 (33%) of 21 cases showed decreased CK20 expression to a certain extent in the invasive component. Only 2 cases showed significant increase of p53 expression in the invasive component compared with the noninvasive component. Two cases showed increase of Ki-67 labeling from less than 5% in the noninvasive to 20% and 40%, respectively, in the invasive component. High Ki-67 labeling was present in a significant portion of invasive LGPUC cases in both noninvasive and invasive components, much higher than in previous studies of noninvasive LGPUC. Whether higher Ki-67 in these cases is associated with more aggressive disease warrants further study. In general, it is not very helpful to use immunostains in diagnosis and predicting prognosis. This is the largest series to study the IHC characteristics of this entity.

New and contemporary markers of prognosis in nonmuscle invasive urothelial cancer

Nonmuscle invasive (NMI) urothelial cancer (UC) is associated with varied biological potential. It is characterized by frequent recurrence and progression, which thus worsens the oncological outcome. Nearly three-quarters of NMI UCs recur within 5 years, whereas half can progress during follow-up. Progression is particularly seen in T1 and carcinoma in situ (CIS). Undoubtedly, NMI UC is one of the most expensive cancers to manage. The European Organisation for Research and Treatment of Cancer (EORTC) risk calculator is a commonly used tool for assessing the recurrence and progression potential of a newly diagnosed cancer. The parameters used in the assessment are tumor size and number, pathological stage and grade of the cancer, presence of CIS, and prior recurrence rate. The main advantages of the EORTC tool are its ease of use and the lack of need to run expensive molecular tests. However, reproducibility of pathologic stage and grade is modest, which is a concern to clinicians. Molecular markers have potential for predicting the clinical outcome of NMI UC, given that clinico-pathologic variables are not sufficient for prediction of prognosis in an individual. Significant work has been done in the past 2 decades in understanding the molecular biology of bladder cancer; however, the translational value of this knowledge remains poor. The role for molecular markers in predicting recurrence seems limited because multifocal disease and incomplete treatment are probably more important for recurrence than the molecular features of a resected tumor. Urinary markers have very limited value in prognostication of bladder cancer and are used (mainly as an adjunct to cytology) for detection and surveillance of urothelial cell cancer recurrence. Prediction of progression with molecular markers holds considerable promise. Nevertheless, the contemporary value of molecular markers over clinico-pathologic indexes is limited.

Muscle-invasive bladder cancer is characterized by overexpression of thymidine kinase 1

OBJECTIVE

Thymidine kinases have an important role in the synthesis of DNA and exhibit high activity in rapidly proliferating cells. Thymidine kinase 1 (TK1) activity has been shown to be increased in various cancer types and proposed as a prognostic parameter. Aim of the present study was to investigate TK1 in muscle-invasive urothelial carcinoma (UC).

METHODS

Corresponding UC and benign samples from paraffin embedded tissue of 111 patients treated with cystectomy for invasive UC from 1996 to 2006 were immunohistochemically (IHC) assessed for TK1. IHC expression patterns were evaluated in a semiquantitative fashion by 2 independent reviewers. Localization of staining was categorized into pure nuclear and additional cytoplasmic localization. Uni- and multivariate analyses were performed to assess differential expression in normal and UC tissue and to evaluate the diagnostic and predictive capability of TK1 by correlation to clinical data. To correlate TK1 expression with molecular subtypes of UC, analysis of TK1 RNA expression levels of the Cancer Genome Atlas UC cohort was performed.

RESULTS

TK1 was significantly overexpressed in invasive UC, compared to benign urothelium (P<0.0001), and cytoplasmic expression was more often found in cancer tissue than in benign tissue (P = 0.0001). No correlations of TK1 protein expression patterns to standard histopathological determinants were detected. In univariate analysis, TK1 nuclear and cytoplasmic expression was associated with improved cancer-specific survival (P = 0.0119). However, only metastasis status and histologic grade were identified as independent predictors of cancer-specific survival in multivariate analysis. TK1 expression was merely found in the basal layers of benign urothelium. RNA overexpression of TK1 could be correlated to the biologically more aggressive basal UC subtype.

CONCLUSIONS

TK1 expression is significantly different in invasive UC and benign urothelium, which underlines its potential as a diagnostic marker. Although TK1 is considered to be a marker of proliferation, and TK1 RNA overexpression is associated with an aggressive UC subtype, its capability as a predictive IHC biomarker for invasive UC remains limited.

Minichromosome maintenance complex component 7 has an important role in the invasion of papillary urothelial neoplasia

The aims of the present study were to investigate the expression of minichromosome maintenance complex component 7 (MCM7) and determine its association with tumor proliferation and invasion in pathological tumor (pT)a and pT1 papillary urothelial neoplasia. The MCM7, MCM3 and Ki67 proteins were detected in 154 cases of urothelial neoplasia using immunohistochemical analysis. The expression of MCM7 significantly increased (P<0.001) as the pathological stage and grade progressed between inverted papilloma, papillary urothelial neoplasm of low malignant potential (PUNLMP), pTa tumor and pT1 tumor. However, no statistically significant difference in MCM7 staining was observed between low-grade pTa tumors and PUNLMP (P=0.2294). In contrast to MCM7, MCM3 was highly expressed in all stages of urothelial neoplasia, with no statistically significant differences observed between the tumor types (P=0.2993, 0.3885 and 0.8489 for pTa tumors, PUNLMP and inverted papiloma, respectively). Furthermore, MCM7 expression was elevated with increased tumor grade and was positively correlated with Ki67 expression (r_s =0.9106, P<0.001). However, MCM3 expression was not correlated with MCM7 or Ki67 expression (r_s =0.0734, P=0.3657 and r_s =0.0638, P=0.4318, respectively). In conclusion, MCM7 overexpression may simultaneously promote tumor proliferation and invasion. Furthermore, it may be a reliable marker for the pathological differential diagnosis of pTa and pT1 papillary urothelial neoplasms; therefore, MCM7 expression may be used to predict tumor prognosis and behavior.

Neutrophil-lymphocyte ratio as a predictor of recurrence and progression in patients with high-grade pT1 bladder cancer

INTRODUCTION

We investigated the value of the preoperative neutrophil-lymphocyte ratio (NLR) in predicting recurrence and progression of high-grade pT1 non-muscle-invasive tumour in patients with bladder cancer during a 5-year follow-up period.

METHODS

We retrospectively reviewed data of 1100 patients with bladder cancer; these patients underwent transurethral resection and were monitored at multiple centres from 2008 to 2013. In total, 166 consecutive and newly diagnosed patients with high-grade pT1 tumours were included in this study. The NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count.

RESULTS

Of the 166 patients, 152 were male. The patients were evaluated as two separate groups in terms of recurrence and progression. The mean follow-up period was 24.2 months (interquartile range 13.8-36.6 months). A statistically significant difference was found between recurrence and tumour size (p = 0.001), number of tumours (p < 0.001), NLR (p < 0.001), and smoking (p = 0.007). No statistically significant correlation was found between NLR and progression. According to receiver operating characteristic (ROC) analysis, the optimum cut-off value for the NLR was ≥2.43 (74% sensitivity, 60% specificity, p < 0.001; area under the curve [AUC] 0.687, 95% confidence interval [CI] 0.607-0.767). Multivariate logistic regression analysis determined that the following factors were independent predictors of recurrence in patients with high-grade pT1 non-muscle-invasive bladder cancer: tumour number (OR 5.32, 95% CI 2.10-12.90), NLR of ≥2.43 (OR 2.587; 95% CI 1.156-5.789), and smoking (OR 4.17, 95% CI 1.31-13.21).

CONCLUSION

A high preoperative NLR may play an important role in predicting recurrence of superficial transitional cell type high-grade pT1 bladder tumours. Prospective studies are required to validate the role of NLR as a prognostic marker in high-grade pT1 bladder tumours.

Improving Selection Criteria for Early Cystectomy in High-Grade T1 Bladder Cancer: A Meta-Analysis of 15,215 Patients

Purpose

High-grade T1 (HGT1) bladder cancer is the highest risk subtype of non–muscle-invasive bladder cancer, with highly variable prognosis, poorly understood risk factors, and considerable debate about the role of early cystectomy. We aimed to address these questions through a meta-analysis of outcomes and prognostic factors.

Methods

PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and American Society of Clinical Oncology abstracts were searched for cohort studies in HGT1. We pooled data on recurrence, progression, and cancer-specific survival from 73 studies.

Results

Five-year rates of recurrence, progression, and cancer-specific survival were 42% (95% CI, 39% to 45%), 21% (95% CI, 18% to 23%), and 87% (95% CI, 85% to 89%), respectively (56 studies, n = 15,215). In the prognostic factor meta-analysis (33 studies, n = 8,880), the highest impact risk factor was depth of invasion (T1b/c) into lamina propria (progression: hazard ratio [HR], 3.34; P < .001; cancer-specific survival: HR, 2.02; P = .001). Several other previously proposed factors also predicted progression and cancer-specific survival (lymphovascular invasion, associated carcinoma in situ, nonuse of bacillus Calmette-Guérin, tumor size > 3 cm, and older age; HRs for progression between 1.32 and 2.88, P ≤ .002; HRs for cancer-specific survival between 1.28 and 2.08, P ≤ .02).

Conclusion

In this large analysis of outcomes and prognostic factors in HGT1 bladder cancer, deep lamina propria invasion had the largest negative impact, and other previously proposed prognostic factors were also confirmed. These factors should be used for prognostication and patient stratification in future clinical trials, and depth of invasion should be considered for inclusion in TNM staging criteria. This meta-analysis can also help define selection criteria for early cystectomy in HGT1 bladder cancer, particularly for patients with deep lamina propria invasion combined with other risk factors.

Concurrence of villous adenoma and non-muscle invasive bladder cancer arising in the bladder: a case report and review of the literature

BACKGROUND

Villous adenoma arising in the urinary tract is rare tumor. Most cases have been identified as benign neoplasm in the colon. Villous adenoma of the gastrointestinal tract is thought arise from premalignant polyps. Here, we report a case of concurrence of villous adenoma and non-muscle invasive bladder cancer.

CASE PRESENTATION

An 85-year-old woman presented at our office because of gross hematuria. Cystoscopic examination detected two papillary tumors in the bladder. Each tumor was resected and diagnosed, respectively. Histopathology confirmed that the resected one tumor was a villous adenoma, and the other was urothelial carcinoma (T1, high grade). Immunostaining for cytokeratin (CK) 7, CK20 and Ki-67 confirmed that CK7: (-), CK20: (+) and Ki-67: (<=30%) in villous adenoma while CK7: (+), CK20: (+), and Ki-67: (70%) in urothelial carcinoma. Three months later from TUR, urothelial carcinoma recurred in the trigone. She received adjuvant intravesical immunotherapy with BCG post TUR for the recurrence site.

CONCLUSION

There were no specific findings on ultrasonography, CT, MRI or cystoscopic examination morphologically. Therefore, pre-pathological villous adenoma of the bladder is extremely difficult to diagnose. There are some case reports of solitary villous adenoma in the bladder or with coexisting adeno carcinoma. However, to the best of our knowledge, this is only the second report of villous adenoma in the bladder of coexisting urothelial carcinoma that has been published in the literature. Premalignant villous adenoma of the bladder is extremely rare and difficult to diagnose without histologic examination. Any suspicious lesion of the bladder should be biopsied and/or resected to confirm histology.

Oncological outcome of primary versus secondary muscle-invasive bladder cancer is comparable after radical cystectomy

BACKGROUND

High-risk non-muscle-invasive bladder cancer (NMIBC) progressing to muscle-invasive bladder cancer (MIBC) is associated with adverse tumour biology. It is unclear, however, whether outcome of NMIBC progressing to MIBC is adverse compared to primary MIBC and whether NMIBC of higher risk of progression to MIBC is adverse compared to NMIBC of lower risk.

OBJECTIVE

Our objective was to assess cancer-specific survival (CSS) following radical cystectomy (RC) for primary MIBC and for NMIBC progressing to MIBC in dependence of EORTC risk score.

MATERIALS AND METHODS

Clinical and histopathological characteristics and CSS of 150 patients were assessed. Secondary MIBCs were stratified by EORTC risk score at the last transurethral resection of bladder tumour for NMIBC.

RESULTS

CSS did not differ significantly between primary and secondary MIBC (p = 0.521). Secondary MIBC with high EORTC score had significantly shorter CSS compared to secondary MIBC with intermediate EORTC score (p = 0.029). In multivariable analysis, pathological tumour stage (HR = 3.77; p = 0.020) and lymph node stage (HR = 2.34; p = 0.022) were significantly correlated with CSS.

CONCLUSION

While the outcome of secondary MIBC is not generally adverse compared to primary MIBC, the EORTC risk score not only reflects high risk of progression of NMIBC to MIBC, but also worse outcome following RC for secondary MIBC. Timely RC should thus be debated in high-risk NMIBC.

Predictive value of Sox2 expression in transurethral resection specimens in patients with T1 bladder cancer

Sox2 is thought to be an important regulator of self-renewal in embryonic stem cell. According to the cancer stem cell (CSC) theory, the overexpression of Sox2 is potentially involved in carcinogenesis and could affect tumor recurrence and metastasis. Previous study proved Sox2 might be prognostic marker for multiple human malignancies. The purpose of this study was to investigate the clinicopathological significance of Sox2 expression in human non-muscle-invasive bladder cancer. We examined Sox2 expression in 32 paired non-muscle-invasive bladder cancer tissues and adjacent non-cancerous tissues by quantitative real-time RT-PCR (qrtRT-PCR). In addition, we analyzed Sox2 and Ki-67 expression in 126 non-muscle-invasive bladder cancer samples and bladder cancer cell line T24 by immunohistochemistry and immunofluorescence assays. The recurrence-free survival was determined by Kaplan-Meier method and log-rank test. Cox regression was adopted for univariate and multivariate analyses of prognostic factors. The expression of Sox2 was significantly increased in non-muscle-invasive bladder cancer tissues. Sox2 expression was significantly correlated with that of Ki-67 (P < 0.001). The expression of Sox2 was significantly associated with tumor size (P = 0.006), tumor number (P = 0.037), and tumor grade (P < 0.001). Patients with high Sox2 expression had significantly poorer recurrence-free survival (P = 0.0002) when compared with patients with the low expression of Sox2. On multivariate analysis, Sox2 expression and tumor grade were found to be independent prognostic factors for recurrence-free survival (P < 0.05). Our data suggested for the first time that the high expression of Sox2 may contribute to the development of non-muscle-invasive bladder cancer and serve as a novel prognostic marker in patients with T1 bladder cancer.

High-risk non-muscle-invasive bladder cancer: update for a better identification and treatment

PURPOSE

Despite standard treatment with transurethral resection (TUR) and adjuvant bacillus Calmette-Guérin (BCG), many high-risk bladder cancers (HRBCs) recur and some progress. Based on a review of the literature, we aimed to establish the optimal current approach for the early diagnosis and management of HRBC.

METHODS

A MEDLINE® search was conducted to identify the published literature relating to early identification and treatment for non-muscle-invasive bladder cancer. Particular attention was paid to factors such as quality of TUR, importance of second TUR, substaging, and CIS. In addition, studies on urinary markers, photodynamic diagnosis, predictive clinical and molecular factors for recurrence and progression after BCG, and best management practice were analysed.

RESULTS AND CONCLUSIONS

Good quality of TUR and the implementation of photodynamic diagnosis in selected cases provide a more accurate diagnosis and reduce the risk of residual tumour in HRBC. Although insufficient evidence is available to warrant the use of new urinary molecular markers in isolation, their use in conjunction with cytology and cystoscopy may improve early diagnosis and follow-up. BCG plus maintenance for at least 1 year remains the standard adjuvant treatment for HRBC. Moreover, there is enough evidence to consider the implementation of new specific risk tables for patients treated with BCG. In HRBC patients with poor prognostic factors after TUR, early cystectomy should be considered.