1418P - Tumor microenvironment B-cell abundance and survival in resectable gastric cancer: A translational analysis from the CLASSIC trial

Background

While the significance of the tumor microenvironment (TME) in influencing prognosis and therapy response in gastric cancer (GC) is emerging, the specific role of B-cells remains poorly understood. We aimed to investigate the contribution of B-cells in the TME in patients with locally advanced GC recruited to the Korean CLASSIC trial.

Methods

Using CD20 immunohistochemistry, we studied B-cell abundance in tissue microarrays from resection specimens from 459 CLASSIC trial GC patients (278 diffuse-type and 181 intestinal-type). The relationship between B-cell abundance, Lauren subtype, adjuvant chemotherapy (AC) and overall survival (OS) was analysed.

Results

CD20 abundance was significantly higher in diffuse-type GC compared to intestinal-type (p=0.000012). OS in diffuse-type GC was shorter and CD-20 low diffuse-type had the shortest OS compared to all other patients (median OS 49 months vs 62 months, HR=1.9, 95%-CI: 1.2-3, p=0.003). CD-20 low diffuse-type OS was even poorer if they did not receive AC (median OS 45 months vs 61 months, HR=2.3, 95%-CI:1.3-4.2, p=0.005).

Conclusions

CD20 abundance is higher in diffuse-type GC. Patients with CD20-low diffuse-type GC have the poorest survival, especially if they do not receive AC. CD20 holds potential as a prospective therapeutic target or a potential predictive biomarker for systemic therapy in the future. Further investigations on the predictive and prognostic value of B-cells in GC are necessary to validate our findings.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

M. Sachdeva: Financial Interests, Personal, Invited Speaker, Honorarium: Ipsen; Financial Interests, Personal, Other, Travel Costs: GSK. J. Cheong: Financial Interests, Personal, Advisory Role: ImmunoMET; Financial Interests, Personal, Research Funding: ImmunoMET. H.I. Grabsch: Financial Interests, Personal, Other, Honoraria: MSD NL. R. Sundar: Financial Interests, Personal, Advisory Board, Advisory Board, Invited Speaker: Bristol Myers Squibb, MSD; Financial Interests, Personal, Advisory Board: Merck, Bayer, Novartis, GSK, Pierre Fabre, Tavotek, AstraZeneca, Daiichi Sankyo, BeiGene; Financial Interests, Personal, Advisory Board, Advisory Board, Invited Speaker, Travel: Eisai; Financial Interests, Personal, Advisory Board, Advisory Board, Invited Speaker, Travel for conferences. Funding declared is over several years (<10,000 Euro per year): Taiho; Financial Interests, Personal, Invited Speaker: Eli Lilly, BMS, Roche, Taiho, AstraZeneca, DKSH, Daiichi Sankyo, BeiGene, Astellas; Financial Interests, Personal, Advisory Board, Travel for conference and Advisory Board, funding declared is over several years, All other authors have declared no conflicts of interest.