Abstract 2032
Background
Esophageal and gastric (EG) cancers stand for a considerable amount of cancer cases and deaths worldwide. Although addition of neoadjuvant and/or adjuvant therapy has led to an improved survival in patients with resectable tumours, there is still a great unmet need for novel treatment strategies and complementary biomarkers. This study examined the effect of neoadjuvant chemotherapy on the expression of programmed death receptor 1 (PD-1) and programmed death ligand 1 (PD-L1) in EG adenocarcinoma, as well as the associations of PD-1 and PD-L1 expression with histopathological response and clinical outcome.
Methods
Immunohistochemical expression of PD-1 on tumour-infiltrating immune cells (TIC) and of PD-L1 on tumour cells (TC) and TIC was assessed on paired pre-treatment biopsies, post-treatment resected primary tumours and a subset of paired lymph node metastases from a consecutive cohort of 148 patients with neoadjuvant +/- adjuvant treated EG adenocarcinoma.
Results
PD-1 expression was significantly higher in resected tumours and in lymph node metastases compared to biopsies, but the expression of PD-L1 TC and PD-L1 TIC was similar before and after neoadjuvant therapy. PD-1 expression was not associated with histopathological response or with survival. Positive PD-L1 TC expression in biopsies was significantly associated with histopathological response but not with survival, whereas positive PD-L1 TC expression in resected tumours signified a reduced overall survival. High PD-L1 TIC expression in biopsies, but not in resected tumours, was significantly associated with a prolonged overall survival.
Conclusions
Expression of PD-1, but not of PD-L1, is augmented after neoadjuvant treatment. Chemotherapy may however evoke more resistant subsets of PD-L1 positive TC, thus indicating a need for alternative treatment strategies in the adjuvant setting.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Lund University.
Funding
SUS Stiftelse och Donationer Fru Berta Kamprads Stiftelse Vetenskapliga rådet, Projektmedel för forsknings- och Utvecklingsarbete.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5773 - A prospective study of diffusion-weighted magnetic resonance imaging for predicting outcome following chemoradiotherapy, in squamous cell carcinomas of the anus.
Presenter: Rebecca Muirhead
Session: Poster Display session 2
Resources:
Abstract
4581 - Timing to achieve complete response (CR) after definitive chemoradiotherapy (ChRT) in patients with squamous cell carcinoma of the anal (SCCAC) with and without HIV infection: a multicenter retrospective study
Presenter: Marcos Camandaroba
Session: Poster Display session 2
Resources:
Abstract
1712 - Planned organ preservation for T2 T3 M0 rectal adenocarcinoma. A possible option using chemoradiotherapy (CRT) and Contact X-ray Brachytherapy (CXB). A French multicenter study.
Presenter: Jean-Pierre Gérard
Session: Poster Display session 2
Resources:
Abstract
4639 - A Phase 1b Study of E7046 (AN0025) in Combination With Radiotherapy/Chemoradiotherapy (RT/CRT) in Preoperative Treatment of Rectal Cancer
Presenter: Lucjan Wyrwicz
Session: Poster Display session 2
Resources:
Abstract
2310 - Upfront radical surgery with total mesorectal excision (TME) versus preoperative chemoradiotherapy followed by TME in clinical stage II/III patients with rectal cancer: a propensity score analysis
Presenter: Ahrong Ham
Session: Poster Display session 2
Resources:
Abstract
2747 - Neoadjuvant chemoradiotherapy with/without lateral lymph node dissection for low rectal cancer: Which patients can benefit?
Presenter: Daisuke Nishizaki
Session: Poster Display session 2
Resources:
Abstract
2877 - The impact of completeness of chemotherapy on the efficacy of irinotecan in the preoperative chemoradiotherapy of locally advanced rectal cancer.
Presenter: Jingwen Wang
Session: Poster Display session 2
Resources:
Abstract
3050 - Feasibility of robot-assisted surgery in elderly patients with rectal cancer
Presenter: Wei-Chih Su
Session: Poster Display session 2
Resources:
Abstract
4109 - Feasibility of chemoradiotherapy in rectal cancer patients with peritumoral abscesses and fistulas: a case-control non-inferiority trial
Presenter: Valerii Ivanov
Session: Poster Display session 2
Resources:
Abstract
4813 - Differential of the nutritional index before and after neoadjuvant chemoradiotherapy as a prognostic factor of recurrence in patients with locally advanced adenocarcinoma of the rectum
Presenter: Leslie Navia-Ortuño
Session: Poster Display session 2
Resources:
Abstract