Maintenance treatment with gemcitabine have a promising activity on metastatic bladder cancer survival

Gemcitabine maintenance versus observation after first-line chemotherapy in patients with metastatic urothelial carcinoma: a retrospective study

Background

Gemcitabine with platinum is one of the most important first-line treatments for metastatic urothelial cancer (mUC). However, continuation of platinum agents results in cumulative toxicities, such as nephrotoxicity, ototoxicity, and neurotoxicity, which lead to discontinuation of chemotherapy after 4–6 cycles despite a favorable response in the patients. The strategy of maintenance treatment can give clinical benefit to patients, but there is no consensus about maintenance treatment. The aim of this study was to investigate the clinical impact of the gemcitabine maintenance (GEM-m) in mUC patients who achieve disease control from first-line gemcitabine with platinum agents.

Methods

A total of 117 patients who showed response to 4–6 cycles of gemcitabine plus cisplatin or carboplatin as the first-line palliative chemotherapy were reviewed between 2014 to 2018. Patients who were treated with GEM-m received a 1,000 mg/m² dose of gemcitabine on day 1 and 8 for 3 weeks until disease progression or development of unacceptable toxicity. The patients who are not treated with GEM-m were followed up with regular radiologic evaluation. Statistical analyses were performed using the log-rank test and Cox proportional hazards method.

Results

Fifty-eight patients (49.6%) received GEM-m. The median cycle of GEM-m was 4 (range, 1–12). Six patients (10.3%) in the GEM-m group showed an objective response. A median overall survival (OS) of 11.8 months and 9.6 months was observed for the GEM-m and non-GEM-m groups, respectively [HR 0.621; 95% CI, 0.39–0.97; P=0.026]. Additionally, median progression-free survival (PFS) was 4.6 months and 3.3 months in the GEM-m and non-GEM-m groups, respectively [HR 0.612; 95% CI, 0.41–0.91; P=0.009]. Grade 3 or higher neutropenia occurred in 17.2% of patients in the GEM-m and 1.7% in the non-GEM-m group.

Conclusions

Our results suggest that GEM-m can be considered in patients who respond to gemcitabine with platinum. Large-scale prospective study should be warranted.

Up-regulation of DRAM2 promotes tolerance of bladder transitional cell carcinoma to gemcitabine

INTRODUCTION

Bladder transitional cell carcinoma (BTCC) is one of the most prevalent human malignant diseases. Gemcitabine is commonly applied in the treatment of BTCC while acquired gemcitabine resistance has caused a severe impediment to recovery. This study aimed to investigate the function of DRAM2 in regulating gemcitabine resistance of BTCC.

MATERIAL AND METHODS

GSE77883 was introduced to screen out the differentially expressed autophagy-related genes in T24 cells and gemcitabine-resistant T24-GEM cells. After establishing T24-GEM cells ourselves, aberrant expression of DRAM2 was detected by qRT-PCR and Western blot. After stably manipulating the expression of DRAM2 in T24 and T24-GEM cells, the changes of cell biological functions under gemcitabine treatment were compared, including cell viability, apoptosis and autophagy, using colony formation, flow cytometry and electron microscopy respectively.

RESULTS

DRAM2 was up-regulated in gemcitabine-resistant T24-GEM cells. Silencing of DRAM2 in T24-GEM cells inhibited the cell autophagy induced by treatment with gemcitabine and contributed to attenuated gemcitabine resistance. Also, overexpression of DRAM2 in T24 cells enhanced the autophagy, strengthened the chemoresistance and decreased the cell apoptosis rate under the treatment with gemcitabine.

CONCLUSIONS

Our data suggested that downregulation of DRAM2 rescued the sensitivity of T24-GEM cells to gemcitabine, providing an appropriate therapeutic target for BTCC treatment.