Abstract 3982
Background
A special role in the tumour progression is played by heterogeneous components of the microenvironment of tumours, premetastatic tumour niches, influencing which seems likely to change the disease course. Our purpose was to analyze some characteristics of the local cellular immunity in metastatic GC.
Methods
33 GC patients aged 30-80 years were divided into 2 groups: group 1 – M0, non-metastatic GC, n = 17, mean age 61.7±8.9 years (G2 – 11, G3 – 6 patients); group 2 – M1, GC with peritoneal and omentum metastases, n = 16, mean age 58.7±11.5 years (G2 – 7, G3 – 5, G4 - 3 patients). Tumours (T), peritumoral tissues (PT), omentum (O) and peritoneum (P) tissues were studied. Lymphocytes were determined by flow cytometry using FACSCantoII (BD) and T-, B-, NK antibody panels; quantitative content of DN (CD3+CD4-CD8-), DP (CD3+CD4+CD8+) T lymphocytes and regulatory (T-regs) T cells (CD4+CD25+CD127dim) was studied.
Results
Patients with M1 GC demonstrated increased CD3+ lymphocytic infiltration of T, PT, O and P tissues. IRI in M1 O was significantly higher than in M0 (1.95±0.3 vs 0.7±0.2), being similar in other tissues. Levels of DN lymphocytes were lower in O of M1, compared to M0 (7.7±2.5 vs 15.7±5.6, p ≤ 0.05). Contents of NK cells, NKT lymphocytes significantly decreased in O of M1 patients, compared to M0 (3.3≤1.1 vs 14.0≤2.3 and 1.7±0.5 vs 3.8±0.8, respectively). Higher levels of NKT lymphocytes were registered in M1 PT, compared to M0 (3.3±1.1 vs 1.3±0.4), as well as lower levels of NK cells in T (2.3±0.9 vs 5.33±0.2). Percentage of Treg lymphocytes in P and O were significantly lower in M1 than in M0 (respectively, 6.9±1.5 vs 12.6±4.9 and 5.9±1.3 vs 12.6±4.9). Higher amount of B lymphocytes was registered in all tissues of M1 patients, compared to M0, maximal in O (13.1±3.3 vs 3.4±1.5), T (23.5±5.1 vs 17.2±2.3) and P (8.2±3.4 vs 3.5±1.2), while in PT it was lower (15.7±4.2 vs 43.7±4.5).
Conclusions
GC metastasis to the omentum and peritoneum is characterized by a change in their immunological features – a decrease in the tissue level of NK and NKT lymphocytes, a loss in the prevalence of CD3+CD8+ due to an increase in the number of CD3+CD4+ cells, and an increase in the level of CD19 + (B2) lymphocytes. This probably contributes to the appearance of metastatic lesions in these organs in gastric cancer.
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
5205 - Immune status of patients with different stages of colorectal cancer with and without circulating tumor cells
Presenter: Anastasia Sitkovskaya
Session: Poster Display session 2
Resources:
Abstract
5658 - Detection of 5-hydroxymethylcytosine in Circulating-Free DNA for Early Diagnosis of Colorectal Cancer
Presenter: Tianyu Liu
Session: Poster Display session 2
Resources:
Abstract
5779 - Detection of 5-hydroxymethylcytosine in Circulating-Free DNA for Prediction of The Efficacy of Conversion Therapy for Colorectal Cancer Liver Metastases
Presenter: Wenju Chang
Session: Poster Display session 2
Resources:
Abstract
4672 - mCRC gene profiling using the Idylla platform
Presenter: Christopher Bricogne
Session: Poster Display session 2
Resources:
Abstract
3393 - PIK3CA mutation in metastatic colorectal cancer (mCRC): association with clinico-pathological features and outcome
Presenter: Valentina Fanotto
Session: Poster Display session 2
Resources:
Abstract
1317 - Patient-Derived Xenografts (PDX) Identifies JMJD6 Inhibitor as an Effective Therapeutic Medicine in Colorectal Cancer.
Presenter: Feng Ye
Session: Poster Display session 2
Resources:
Abstract
1228 - DACH1 induced stemness of intestinal organoids by directly suppressing BMP signaling and contributes to intestinal tumorigenesis
Presenter: Xiang Hu
Session: Poster Display session 2
Resources:
Abstract
1147 - miR-148a inhibits early relapsed colorectal cancers and the secretion of VEGF by indirectly targeting HIF-1α under non-hypoxia/hypoxia conditions
Presenter: Hsiang-lin Tsai
Session: Poster Display session 2
Resources:
Abstract
1158 - Long noncoding RNA CASC21 promotes cell proliferation and metastasis in colon cancer.
Presenter: Qun Zhang
Session: Poster Display session 2
Resources:
Abstract
1259 - Prognostic and Predictive Impact On FMS-like Tyrosine Kinase 3 (FLT3) Amplification In Patients With Metastatic Colorectal Cancer
Presenter: Hiroko Hasegawa
Session: Poster Display session 2
Resources:
Abstract