Effect of neoadjuvant chemotherapy in patients undergoing radical cystectomy for muscle-invasive bladder cancer: a retrospective, multi-institutional study

Neoadjuvant Chemotherapy for Different Stages of Muscle-Invasive Bladder Cancer: A Systematic Review and Meta-analysis

The purpose of this meta-analysis is to determine the survival benefits and pathological outcomes of neoadjuvant chemotherapy (NAC) combined with radical cystectomy (RC) administered to patients with cT2 or cT3-4N0M0 muscle-invasive bladder cancer (MIBC). PubMed, Embase, and the Cochrane Library were searched for comparing the use of NAC in combination with RC and RC alone in patients with different MIBC stages. A fixed effects model was used to calculate hazard ratio (HR) and odds ratio (OR) with 95% confidence intervals (CIs), and the I² statistic was used to assess heterogeneity. Moreover, we determined possible sources of heterogeneity by subgroup and sensitivity analyses. Fifteen studies were finally selected. For cT2 bladder cancer, NAC combined with RC significantly increased the rates of pathological complete response (pCR) (OR = 4.84, 95% CI: 1.18–19.92, p = 0.029) but did not improve overall survival (OS) (HR = 0.86, 95% CI: 0.72–1.02, p = 0.078) across six studies. Regarding cT3-4 bladder cancer, NAC has a significantly improved effect on OS (HR = 0.69; 95% CI: 0.59–0.81, p < 0.001, across seven studies and 5726 patients) and pCR (pooled OR = 4.80; 95% CI: 2.06–11.23, p < 0.001, across two studies) than RC alone. Most studies were randomized prospective trials (level 1 evidence), and all the effects were irrespective of the type of study design and did not vary between subgroups of patients. In conclusion, NAC combined with RC is recommended for patients with T3-4aN0M0 but not for patients with T2N0M0.

Neoadjuvant chemotherapy with dose dense MVAC is associated with improved survival after radical cystectomy compared to other cytotoxic regimens: A tertiary center experience

INTRODUCTION

Neoadjuvant chemotherapy has become standard of care for cisplatin-eligible patients with muscle-invasive bladder cancer qualified to radical cystectomy, providing a modest increase in 5-year overall survival rate. Several regimens are being employed for neoadjuvant treatment, largely because of their efficacy in metastatic setting. There is however a scarcity of evidence on the optimal cytotoxic regimen for neoadjuvant chemotherapy.

OBJECTIVES

We evaluated the efficacy of different protocols of neoadjuvant chemotherapy amongst patients who underwent radical cystectomy at our institution.

METHODS

This is a single-center, retrospective, observational study including a cohort of 220 patients who underwent radical cystectomy between 2014 and 2020. The neoadjuvant chemotherapy cohort included 79 patients and was compared to the cohort of historical controls including 141 patients operated prior to routine administration of neoadjuvant chemotherapy and those who opted for upfront surgery.

RESULTS

Administration of neoadjuvant chemotherapy decreased the risk of overall and cancer-specific mortality HR = 0.625 (95% CI 0.414-0.944), p = 0.025 and HR = 0.579 (95% CI 0.348-0.964), p = 0.036. Rates of downstaging, complete responses, lymph node metastasis, extravesical extension and positive surgical margins significantly favored neoadjuvant chemotherapy. Out of cytotoxic regimens, dose-dense MVAC and gemcitabine-cisplatin were similarly efficacious providing 46.9% and 50% of downstaging to <ypT2N0 respectively, including 30.6% and 25% of complete remissions. However, only dose-dense MVAC was associated with reduction of all-cause and cancer specific mortality risk HR = 0.385 (95% CI 0.214-0.691) p = 0.001 and HR = 0.336 (95% CI 0.160-0.703), p = 0.004 respectively.

CONCLUSIONS

Our study implies that neoadjuvant chemotherapy with subsequent radical cystectomy provides significant improvement over upfront surgery in locoregional control and long-term prognosis of muscle-invasive bladder cancer. The urologic community should strive to maximize utilization of neoadjuvant chemotherapy, yet further research, including randomized control trials, is needed to validate superiority of dose-dense MVAC as the preferred regimen for cisplatin-eligible patients.

Integrated Analysis of a Competing Endogenous RNA Network Reveals a Prognostic lncRNA Signature in Bladder Cancer

Long non-coding RNAs (lncRNAs) act as competing endogenous RNAs (ceRNAs) to regulate mRNA expression through sponging microRNA in tumorigenesis and progression. However, following the discovery of new RNA interaction, the differentially expressed RNAs and ceRNA regulatory network are required to update. Our study comprehensively analyzed the differentially expressed RNA and corresponding ceRNA network and thus constructed a potentially predictive tool for prognosis. “DESeq2” was used to perform differential expression analysis. Two hundred and six differentially expressed (DE) lncRNAs, 222 DE miRNAs, and 2,463 DE mRNAs were found in this study. The lncRNA-mRNA interactions in the miRcode database and the miRNA-mRNA interactions in the starBase, miRcode, and mirTarBase databases were searched, and a competing endogenous RNA (ceRNA) network with 186 nodes and 836 interactions was subsequently constructed. Aberrant expression patterns of lncRNA NR2F1-AS1 and lncRNA AC010168.2 were evaluated in two datasets (GSE89006, GSE31684), and real-time polymerase chain reaction was also performed to validate the expression pattern. Furthermore, we found that these two lncRNAs were independent prognostic biomarkers to generate a prognostic lncRNA signature by univariate and multivariate Cox analyses. According to the lncRNA signature, patients in the high-risk group were associated with a poor prognosis and validated by an external dataset. A novel genomic-clinicopathologic nomogram to improve prognosis prediction of bladder cancer was further plotted and calibrated. Our study deepens the understanding of the regulatory ceRNA network and provides an easy-to-do genomic-clinicopathological nomogram to predict the prognosis in patients with bladder cancer.

A Newly Defined Pyroptosis-Related Gene Signature for the Prognosis of Bladder Cancer

BACKGROUND

Bladder cancer (BC), as the most common urinary system tumor type and the main cause of tumor-related death, has an unsatisfactory prognosis. In recent years, related literature has proposed that cell pyroptosis is an inflammatory form of programmed cell death. However, in BC, the relationship between the expression of pyroptosis-related genes and the prognosis has not been elucidated.

METHODS

We got the RNA sequencing data from TCGA and GEO datasets. Fifty-two pyroptosis-related genes were extracted for further explore. Then, we compared the gene expression levels between the normal bladder and BC tissues. After that, we develop and validate a pyroptosis-related gene prognostic model and made following functional enrichment analysis and single-sample gene set enrichment analysis of the differentially expressed genes between the high- and low-risk groups.

RESULTS

Twenty-nine differentially expressed genes (DEGs) were found between normal and tumor tissues. Based on the median score calculated by the risk score formula from 8 pyroptosis-related genes, 414 patients were equally divided into low- and high-risk subgroups. The survival probability of BC patients in the high-risk group was significantly lower than that in the low-risk group (P < 0.001). Through multivariate analysis, our risk score is an independent factor predicting OS in BC patients. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis show that high-risk populations are rich in immune-related genes and have a decreased immune status. All the above results have been externally verified from GEO cohort.

CONCLUSION

Pyroptosis-related genes are closely related to tumor immunity and are a potential prognostic tool for predicting BCs.

Meta-analysis of neoadjuvant chemotherapy compared to radical cystectomy alone in improving overall survival of muscle-invasive bladder cancer patients

BACKGROUND

Most patients with muscle-invasive bladder cancer (MIBC) developed metastasis within 2 years, even after radical cystectomy (RC). The recurrence rate of MIBC was more than 50% of the cases. A meta-analysis conducted by Yin et al. showed that neoadjuvant chemotherapy (NAC) + RC improves overall survival in MIBC compared with RC only. However, a new meta-analysis by Li et al. concluded that NAC + RC was not superior to RC only in improving overall survival. The inconsistencies of these studies required further comprehensive analysis to recommend NAC use in bladder cancer treatment. Therefore, this meta-analysis aims to analyze previous studies that compare the efficacy of NAC + RC versus RC only to improve overall survival of MIBC.

METHODS

The articles were searched using Pubmed with keywords "muscle-invasive bladder cancer", "neoadjuvant chemotherapy", "cystectomy", and "overall survival". The articles that were published until June 2020 were screened. The overall survival outcome was analyzed as hazard ratio (HR) and presented in a forest plot.

RESULT

Seventeen studies were included in meta-analysis with a total sample of 13,391 patients, consist of 2890 received NAC followed by RC and 10,418 underwent RC only. Two studies used methotrexate/vinblastine/doxorubicin/cisplatin (MVAC), two studies used gemcitabine/cisplatin (GC), one study used Cisplatin-based regimen, one study used MVAC or GC, one study used gemcitabine/carboplatin (GCarbo) or GC or MVAC, one study used Cisplatin/Gemcitabine or MVAC, one study used Cisplatin only, one study used Cisplatin-based (GC, MVAC) or non-Cisplatin-based (combined paclitaxel/gemcitabine/carboplatin), one study used GC, MVAC, Carboplatin, or Gemcitabine/Nedaplatin (GN), and five studies did not mention the regimen The overall survival in the NAC + RC only group was significantly better than the RC only group (HR 0.82 [0.71-0.95], p = 0.009).

CONCLUSION

NAC + RC is recommended to improve overall survival in MIBC patients. A further study assessing side effects and quality of life regarding NAC + RC is needed to establish a strong recommendation regarding this therapy.