Prediction of recurrence and progression in patients with T1G3 bladder cancer by gene expression of circulating tumor cells

Integrative Analysis Identified MCT4 as an Independent Prognostic Factor for Bladder Cancer

Background

Bladder cancer is the 10th most common cancer and most common urothelial malignancy worldwide. Prognostic biomarkers for bladder cancer patients are required for individualized treatment. Monocarboxylate transporter 4 (MCT4), encoded by SLC16A3 gene, is a potential biomarker for bladder cancer because of its crucial role in the lactate efflux in the aerobic glycolysis process. We aimed to study the association between MCT4 expression and the overall survival (OS) of bladder cancer patients.

Methods

The published single-cell RNA sequencing data of 49,869 bladder cancer cells and 15,827 normal bladder mucosa cells and The Cancer Genome Atlas (TCGA) bladder cancer cohort data were used to explore the mRNA expression of SLC16A3 in bladder cancer. Eighty-nine consecutive bladder cancer patients who had undergone radical cystectomy were enrolled as a validation cohort. The expression of MCT4 proteins in bladder cancer specimens was detected using immunohistochemistry staining. The Kaplan–Meier survival analysis and Cox regression were performed to analyze the association between MCT4 protein expression and OS in bladder cancer patients.

Results

SLC16A3 mRNA was upregulated in bladder cancer cells. The upregulated genes in SLC16A3-positive epithelial cells were enriched in the glycolysis process pathway and monocarboxylic acid metabolic process pathway. Patients with high SLC16A3 mRNA expression showed significantly poor OS (p = 0.016). High MCT4 protein expression was also found to be an independent predictor for poor OS in bladder cancer patients (HR: 2.462; 95% CI: 1.202~5.042, p = 0.014). A nomogram was built based on the results of the multivariate Cox analysis.

Conclusion

Bladder cancer with high SLC16A3 mRNA expression has a poor OS. High MCT4 protein expression is an independent prognostic factor for bladder cancer patients who had undergone radical cystectomy.

Upstaging and Survival Outcomes for Non-Muscle Invasive Bladder Cancer After Radical Cystectomy: Results from the International Robotic Cystectomy Consortium

INTRODUCTION

We sought to describe the incidence, risk factors, and survival outcomes associated with pathological upstaging from non-muscle invasive bladder cancer (NMIBC) to muscle invasive bladder cancer (MIBC) after robot-assisted radical cystectomy (RARC).

METHODS

We reviewed the International Robotic Cystectomy Consortium database between 2004 and 2020. Upstaging was defined as ≥pT2 or pN+ at final pathology from clinical <T2N0M0. Descriptive statistics were used to summarize data. Cochran-Armitage test was used to depict upstaging trend over time. Multivariate regression models were used to depict variables associated with upstaging. Kaplan Meier curves were used to describe disease-specific (DSS), recurrence-free (RFS), and overall survival (OS).

RESULTS

463 patients underwent RARC for NMIBC. Upstaging occurred in 145 (31%) patients. Upstaged patients were older (70 vs 67 years, p <0.01), more likely to have American Society of Anesthesiologists score (≥3) (55% vs 44%, p=0.04) and had higher rate of preoperative hydronephrosis (26% vs 10%, p <0.01). They were more likely to have positive surgical margins (10% vs 3%, p= 0.01), recurrences (28% vs 9%, p<0.01), and to receive adjuvant/salvage treatment (26% vs none, p <0.01). On multivariate analysis, upstaging was associated with older age (OR 1.04; CI 1.01-1.07, p<0.01), cT1 vs cTis (OR 4.25; CI 1.57-11.48, p <0.01), cT1 vs cTa (OR 2.92; CI 1.40-6.06, p<0.01), and preoperative hydronephrosis (OR 3.18; CI 1.60-6.32, p<0.01). Upstaged patients had worse 5-year RFS (53 % vs 85%, log rank p<0.01), DSS (66% vs 93%, log rank p<0.01), and OS (49% vs 74%, log rank p<0.01). The rate of upstaging did not significantly change over time (38% in 2004 to 27% in 2019, p=0.17).

CONCLUSION

Upstaging to MIBC occurred in a significant proportion of patients after RARC for NMIBC and was associated with worse survival outcomes. Older patients, those with cT1 disease and hydronephrosis were more likely to upstage.