Abstract 5204
Background
Microbiota has been linked to the development of multiple cancers through various mechanisms. In bladder cancer (BC), preliminary studies have found alterations in the urinary microbiota of patients with urothelial carcinoma in comparison with healthy individuals. However, the bladder microbiota (BMi) has not been explored. The aims of this study were to characterize the BMi in a cohort of BC patients, to explore differences in the BMi composition between tumor (T) and normal (N) mucosa, and to identify its correlation with clinicopathologic features.
Methods
A total of 58 samples obtained by cystectomy from 32 BC patients (frozen tumor tissues and normal appearing mucosa for 26 patients and 6 tumor tissues) from Hospital General de Elche Biobank (Spain) were included. DNAs isolated from bladder samples were used to perform 16S rRNA gene sequencing (V3 and V4 region). A paired-end 2 × 300 bp cycle run on Illumina MiSeq. Ribosomal Database Project Classifier was used for taxonomical assignment. Statistical analysis was performed using Rstudio platform. Groups of data were compared using Wilcoxon test and Mann Whitney test for 26T vs 26N (paired group) and 32T vs 26N (unpaired group), respectively.
Results
There were no statistically significant differences of diversity between T and N, but there were differences of richness between T and N at the genus level (Chao1 index, p = 0.049). Globally, the most abundant phylum was Firmicutes, followed by Bacteroidetes, Proteobacteria and Actinobacteria. We found that the microbial composition differed significantly between T and N in both groups. At the phylum level, while Cyanobacteria.Chloroplast (0.74% vs 2.44%; p = 0.025) was enriched in T, Actinobacteria were reduced in T. Principal component analysis based on the relative abundance of phylum (36.9% PC1 and 28.7% PC2 of explained variance) revealed a significant separation in bacterial community composition between tumor tissues associated with histological tumor grade (permanova grade =0.036).
Conclusions
Significant differences in the BMi composition associated with tumor grade were observed. Additional studies are needed to determine the role of BMi in the evolution of BC and its therapeutic implications.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1084 - Dissociated responses in patients with metastatic solid tumors treated with immunotherapy
Presenter: Pauline Vaflard
Session: Poster Display session 3
Resources:
Abstract
4600 - Patterns and outcomes related to rapid progressive disease in a cohort of advanced solid tumors treated with immune checkpoint inhibitors (ICIs).
Presenter: Lucio Ghiglione
Session: Poster Display session 3
Resources:
Abstract
3547 - Real World Outcomes of Immune-Related Adverse Events (irAEs) among Patients Receiving Immune Checkpoint Inhibitors (ICIs) in Hospital Settings
Presenter: Saby George
Session: Poster Display session 3
Resources:
Abstract
1124 - Sex-based heterogeneity of efficacy of anticancer immunotherapy
Presenter: Fabio Conforti
Session: Poster Display session 3
Resources:
Abstract
4133 - Comparative efficacy and safety of PD-1/PD-L1 inhibitors for patients with solid tumors: a systematic review and Bayesian network meta-analysis
Presenter: Qingyuan Huang
Session: Poster Display session 3
Resources:
Abstract
2548 - Excess weight and efficacy of anti-PD-1 antibodies in advanced cancer patients
Presenter: Jacobo Rogado
Session: Poster Display session 3
Resources:
Abstract
2228 - Safety and efficacy of anti-PD-1 inhibitor ABBV-181 in lung and head and neck carcinoma
Presenter: Antoine Italiano
Session: Poster Display session 3
Resources:
Abstract
2333 - Efficacy and safety of immune checkpoint inhibitors (ICIs) for treatment of advanced solid tumours in octogenarian patients
Presenter: Soraya Mebarki
Session: Poster Display session 3
Resources:
Abstract
4847 - Association of programmed cell death 1 (PD-1) inhibitor therapy with overall survival (OS) in stage IV melanoma treated with targeted therapies
Presenter: Aracelis Torres
Session: Poster Display session 3
Resources:
Abstract
2215 - Clinical outcomes of immune checkpoint inhibitors in older and younger patients with advanced solid tumours in a real-life setting
Presenter: Pauline Corbaux
Session: Poster Display session 3
Resources:
Abstract