Abstract 1973: Patients with operable esophageal cancer and improved responses to combined chemoradiotherapy and immunotherapy display distinct microbiome profiles enriched in multiple Bacteroides species
Abstract
Background: Preclinical and clinical data indicate that neoadjuvant chemoradiotherapy (CRT) may prime an anti-tumor immunological response in esophageal cancer driven by intratumoral CD8+ T cells and PD-L1 expression. LAG-3 is also highly expressed in esophagogastric cancers. The microbiome, a novel and potentially modifiable, biomarker of IO response, has not yet been examined in the neoadjuvant setting in esophageal cancer and is the goal of our study.
Methods: Fecal samples were collected from patients with stage II/III esophageal or gastroesophageal junction carcinoma eligible for curative resection treated with the standard of care regimen of carboplatin paclitaxel (50mg/m2), radiation 50.4 Gy in 28 fractions and an Ivor-Lewis esophagectomy 6-10 weeks after last CRT and immunotherapy (IO) dose. Patients on arm A (n=11) received 2 cycles of induction with nivolumab plus 3 additional cycles on week 1, 3 and 5 of CRT. Patients on arm B (n=8) received nivolumab plus relatlimab on the same schedule (Clinical trial: NCT03044613). We examined longitudinal fecal samples from n=19 patients across both arms (n=90 samples) using 16S rRNA amplicon sequencing. Patients were classified based on pathological response: complete response (CR) and grades 1, 2, and 3 (G1, G2, G3) with increasing residual tumor visible in the resected specimen. Sequencing data was trimmed and filtered for contaminants, followed by high-resolution taxonomic assignment and normalization of reads across all…
Read the paper
Related studies
- Diagnosis and management of glutaric aciduria type I – revised recommendations
- EZH2 Codon 641 Mutations are Common in BCL2-Rearranged Germinal Center B Cell Lymphomas
- Consensus guidelines for the diagnosis and management of pyridoxine‐dependent epilepsy due to α‐aminoadipic semialdehyde dehydrogenase deficiency
- Systemic Metabolomic Changes in Blood Samples of Lung Cancer Patients Identified by Gas Chromatography Time-of-Flight Mass Spectrometry
- Human OTULIN haploinsufficiency impairs cell-intrinsic immunity to staphylococcal α-toxin
- Discovery of Novel Recurrent Mutations in Childhood Early T-Cell Precursor Acute Lymphoblastic Leukemia by Whole Genome Sequencing - a Report From the St Jude Children's Research Hospital - Washington University Pediatric Cancer Genome Project
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.