Abstract 2439
Background
Tumour infiltrating T cell subsets are associated with a prognosis in gastric cancer (GC). However, there has been no study of T cell subsets on the efficacy of immune checkpoint blockades (ICBs). This study was designed to assess T cell subsets in tumour by using multiplex immunohistochemistry (mIHC) and to evaluate the association of T cell subsets and efficacy of ICBs in patients with GC who received ICBs.
Methods
We assess patients who have treated with ICBs and available tumour tissues before initiation of ICBs. Multiple stainings were performed with different kinds of T cell or immune checkpoint surface markers (CD3, CD4, CD8, PD-L1, PD1, FOXP3, CK, Ki-67, TIM-3, LAG-3, CD45 and CD45RO) in a single section through 12 times-repeated staining-scanning-stripping procedures. Density was defined to be the number of positively-stained cells per mm2.
Results
Eighty-four patients (40 (47.6%) in first- or second-line; 44 (52.4%) in third- or later lines) were analyzed. Patients with MSI-H, EBV and non-MSI/non-EBV were 7 (8.3%), 3 (3.6%) and 74 (88.1%). A high intratumoral CD3+CD8+/CD3+ T cells ratio was associated with better response rate (RR) (34.2% vs 8.8%, p = 0.034) and longer overall survival (OS) (24.3 vs. 5.9 months, p < 0.001). A high CD3+CD8+ density (17.9 vs. 5.9 months, p = 0.001), high stromal CD3+CD4+FOXP3+/CD3+CD4+ T cells ratio (5.5 vs. 2.5 months, p = 0.0001, in PFS), low CD3+CD4+/CD3+ T cells ratio (5.7 vs. 24.3 months, p < 0.001) and low CD3+CD45RO+/CD3+ T cells ratio (7.1 vs. 10.4 months, p = 0.033) were correlated with improved OS. Low CD3+CD4+/CD3+ T cells ratio (33.3% vs. 9.1%, p = 0.041) and high stromal CD3+CD4+Foxp3+/CD3+CD4+ T cells ratio (37.8% vs. 5.7%, p = 0.004) were significantly associated with better tumor response. GC harboring MSI-H and EBV had higher CD3+C8+/CD3+ cells ratio and CD3+CD8+ T cells density than GC with non-MSI/non EBV. Patients with MSI-H and EBV had longer OS than those with non-MSI/non-EBV (not reached to median value, 27.3 months and 7.0 months, p < 0.001).
Conclusions
Composition, density and distribution of T cell subsets in tumour were associated with the response to ICBs. mIHC is a good method to assess T cell subsets in archival tumour tissue.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Seoul National University Hospital.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4304 - A user-friendly nomogram to predict relapse-free survival (RFS) in western patients with resected gastric cancer (GC)
Presenter: Massimiliano Salati
Session: Poster Display session 2
Resources:
Abstract
4546 - Efficacy and toxicity of weekly carboplatin and paclitaxel as induction or palliative treatment in advanced esophageal cancer patients
Presenter: Femke de Man
Session: Poster Display session 2
Resources:
Abstract
5908 - Perioperative chemotherapy with Docetaxel, Oxaliplatin, Fluorouracil and Leucovorin (FLOT) versus Epirubicin, Platinum and Capecitabine or Flourouracil (EOX/ECF) in Resectable Gastric or Gastroesophageal Junction Adenocarcinoma- Safety and response data from India.
Presenter: Tanuj Chawla
Session: Poster Display session 2
Resources:
Abstract
937 - Phase II Study of Preoperative Radiotherapy Combined with S-1 plus Cisplatin in Clinically Resectable Type 4 or Large Type 3 Gastric Cancer: OGSG1205
Presenter: Shunji Endo
Session: Poster Display session 2
Resources:
Abstract
1119 - Observational Study of the Peritoneal Washing Cytology Positive Gastric Cancer without Gross Peritoneal Metastasis Underwent Radical D2 Gastrectomy.
Presenter: Jun Eul Hwang
Session: Poster Display session 2
Resources:
Abstract
3744 - Primary results of multicenter phase II study of neoadjuvant chemotherapy with S-1 and oxaliplatin for locally advanced gastric cancer (Neo G-SOX PII)
Presenter: Akira Miki
Session: Poster Display session 2
Resources:
Abstract
5091 - Multicenter Phase I/II Feasibility Study of Adjuvant Treatment with S-1 in Patients after R0-Resection of Adenocarcinoma of the Stomach and Esophagogastric Junction (GMBH-STO-0114)
Presenter: Kathrin Heinrich
Session: Poster Display session 2
Resources:
Abstract
2891 - A phase I study of Docetaxel/Oxaliplatin/S-1 (DOS) combination neoadjuvant chemotherapy for patients with locally advanced adenocarcinoma of the esophagogastric junction
Presenter: Kei Hosoda
Session: Poster Display session 2
Resources:
Abstract
2994 - Apatinib combined with docetaxel in second-line treatment of advanced gastric cancer: a prospective clinical study (Data updated)
Presenter: Mudan Yang
Session: Poster Display session 2
Resources:
Abstract
3000 - A multicenter phase II study of TAS-114 in combination with S-1 in patients with pre-treated advanced gastric cancer (EPOC1604)
Presenter: Daisuke Takahari
Session: Poster Display session 2
Resources:
Abstract