Emerging personalized approaches for the management of advanced urothelial carcinoma

A Novel CpG Methylation Risk Indicator for Predicting Prognosis in Bladder Cancer

Purpose

Bladder cancer (BLCA) is one of the most common cancers worldwide. In a large proportion of BLCA patients, disease recurs and/or progress after resection, which remains a major clinical issue in BLCA management. Therefore, it is vital to identify prognostic biomarkers for treatment stratification. We investigated the efficiency of CpG methylation for the potential to be a prognostic biomarker for patients with BLCA.

Patients and Methods

Overall, 357 BLCA patients from The Cancer Genome Atlas (TCGA) were randomly separated into the training and internal validation cohorts. Least absolute shrinkage and selector operation (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) were used to select candidate CpGs and build the methylation risk score model, which was validated for its prognostic value in the validation cohort by Kaplan–Meier analysis. Hazard curves were generated to reveal the risk nodes throughout the follow-up. Gene Set Enrichment Analysis (GSEA) was used to reveal the potential biological pathways associated with the methylation model. Quantitative real-time polymerase chain reaction (PCR) and western blotting were performed to verify the expression level of the methylated genes.

Results

After incorporating the CpGs obtained by the two algorithms, CpG methylation of eight genes corresponding to TNFAIP8L3, KRTDAP, APC, ZC3H3, COL9A2, SLCO4A1, POU3F3, and ADARB2 were prominent candidate predictors in establishing a methylation risk score for BLCA (MRSB), which was used to divide the patients into high- and low-risk progression groups (p < 0.001). The effectiveness of the MRSB was validated in the internal cohort (p < 0.001). In the MRSB high-risk group, the hazard curve exhibited an initial wide, high peak within 10 months after treatment, whereas some gentle peaks around 2 years were noted. Furthermore, a nomogram comprising MRSB, age, sex, and tumor clinical stage was developed to predict the individual progression risk, and it performed well. Survival analysis implicated the effectiveness of MRSB, which remains significant in all the subgroup analysis based on the clinical features. A functional analysis of MRSB and the corresponding genes revealed potential pathways affecting tumor progression. Validation of quantitative real-time PCR and western blotting revealed that TNFAIP8L3 was upregulated in the BLCA tissues.

Conclusion

We developed the MRSB, an eight-gene-based methylation signature, which has great potential to be used to predict the post-surgery progression risk of BLCA.

Targeting glycogen metabolism in bladder cancer

Metabolism has been a heavily investigated topic in cancer research for the past decade. Although the role of aerobic glycolysis (the Warburg effect) in cancer has been extensively studied, abnormalities in other metabolic pathways are only just being understood in cancer. One such pathway is glycogen metabolism; its involvement in cancer development, particularly in urothelial malignancies, and possible ways of exploiting aberrations in this process for treatment are currently being studied. New research shows that the glycogen debranching enzyme amylo-α-1,6-glucosidase, 4-α-glucanotransferase (AGL) is a novel tumour suppressor in bladder cancer. Loss of AGL leads to rapid proliferation of bladder cancer cells. Another enzyme involved in glycogen debranching, glycogen phosphorylase, has been shown to be a tumour promoter in cancer, including in prostate cancer. Studies demonstrate that bladder cancer cells in which AGL expression is lost are more metabolically active than cells with intact AGL expression, and these cells are more sensitive to inhibition of both glycolysis and glycine synthesis--two targetable pathways. As a tumour promoter and enzyme, glycogen phosphorylase can be directly targeted, and preclinical inhibitor studies are promising. However, few of these glycogen phosphorylase inhibitors have been tested for cancer treatment in the clinical setting. Several possible limitations to the targeting of AGL and glycogen phosphorylase might also exist.

FGF7 Over Expression is an Independent Prognosticator in Patients with Urothelial Carcinoma of the Upper Urinary Tract and Bladder

PURPOSE

Urothelial carcinoma of the bladder and upper tract is the most common tumor type in the urinary tract but its molecular pathogenesis and survival determinants remain obscure. By data mining a published transcriptomic database of bladder urothelial carcinoma (GSE31684) we identified FGF7 as the most significant gene up-regulated during urothelial carcinoma progression. We then used our well characterized urothelial carcinoma cohort to analyze FGF7 transcript and protein expression, and its clinicopathological significance.

MATERIALS AND METHODS

We performed real-time reverse transcriptase-polymerase chain reaction assay to determine the FGF7 transcript level in 30 fresh samples each of upper tract and bladder urothelial carcinoma. Immunohistochemistry evaluated by H-score was used to determine FGF7 protein expression in 340 upper tract and 295 bladder urothelial carcinomas. Transcript and protein expression were correlated with clinicopathological features. We further evaluated the prognostic significance of FGF7 protein expression for disease specific and metastasis-free survival.

RESULTS

An increased FGF7 transcript level was associated with higher pT stage in upper tract and bladder urothelial carcinoma (p = 0.003 and <0.001, respectively). In the upper tract and bladder carcinoma groups FGF7 protein over expression was also significantly associated with advanced pT status (each p <0.001), lymph node metastasis (p = 0.002 and <0.001), high histological grade (p = 0.019 and <0.001), vascular invasion (each p <0.001), perineural invasion (p = 0.002 and 0.021) and frequent mitoses (p = 0.002 and 0.042, respectively). FGF7 over expression predicted dismal disease specific and metastasis-free survival on univariate and multivariate analysis.

CONCLUSIONS

Our study shows that FGF7 over expression is associated with advanced clinical features in patients with upper tract and bladder urothelial carcinoma, justifying its potential prognostic value for urothelial carcinoma.

High neutrophil-to-lymphocyte ratio persistent during first-line chemotherapy predicts poor clinical outcome in patients with advanced urothelial cancer

BACKGROUND

Increased neutrophil-to-lymphocyte ratio (NLR), an index of systemic inflammation, is associated with poor outcome for various types of cancers. We assessed the role on outcome prediction of NLR at baseline and persistent during first-line chemotherapy in patients with advanced urothelial cancer.

METHODS

We retrospectively reviewed 292 patients with unresectable or metastatic urothelial cancer treated with first-line chemotherapy between January 2003 and December 2012. The cutoff values of NLR (>3 vs. <3) were evaluated before therapy and at day 1 of the second and third cycle (follow-up NLR). After univariate analysis, a multivariate analysis was carried out by Cox regression model and included the following variables: Eastern Cooperative Oncology Group (ECOG) performance status (≥ 2 vs. 0-1), visceral disease (present vs. absent), hemoglobin (<12 g/dL vs. >12 g/dL), pretherapy NLR (>3 vs. <3), and follow-up NLR (>3 vs. ≤ 3).

RESULTS

Patients with pre- and follow-up NLR of >3 had a median progression-free survival of 3.2 months and a median overall survival of 5.7 months. In multivariate analysis, visceral metastases, pretherapy hemoglobin, and follow-up NLR were significant predictors of progression-free survival [hazard ratio (HR) 1.75, P = 0.0001; HR 1.57, P = 0.0015; HR 2.77, P < 0.0001, respectively], and of overall survival (HR 1.60, P = 0.0023; HR 1.59, P = 0.0024; HR 2.89, P < 0.0001, respectively); whereas pretherapy NLR remained as predictor of overall survival only (HR 1.53, P = 0.0101).

CONCLUSIONS

An increased NLR persistent during first-line chemotherapy is an independent predictive factor for patients with advanced urothelial cancer.

Biomarkers for bladder cancer management: present and future

Accurate and sensitive detection of bladder cancer is critical to diagnose this deadly disease at an early stage, estimate prognosis, predict response to treatment, and monitor recurrence. In past years, laboratory diagnosis and surveillance of urinary bladder cancer have improved significantly. Although urine cytology remains the gold standard test, many new urinary biomarkers have been identified. Furthermore, recent advances in genomic studies of bladder cancer have helped to refine our understanding of the pathogenesis of the disease, the biological basis for outcome disparities, and to inform more efficient treatment and surveillance strategies. In this article, the established diagnostic tests, newly identified biomarkers and genomic landscape of bladder cancer will be reviewed.