1582P - Gastroesophageal adenocarcinoma in young adults: Retrospective analysis of clinical and molecular features

Background

Gastroesophageal adenocarcinoma (GEA) in young patients presents poor prognosis due to heterogeneity of the disease and lack of dedicated treatment resulting in high socioeconomic impact. Objective was to explore clinical and molecular features.

Methods

Included patients had diagnosis of GEA at an age of ≤50 years evaluated at Vall d’Hebron University Hospital between 2015 and 2023. Clinical data was obtained retrospectively from the electronic medical history. ESMO Scale of Clinical Actionability for molecular Targets (ESCAT) was used to classify biomarkers. Survival was calculated by the Kaplan-Meier method.

Results

We identified 170 patients with GEA under 50 years. Clinical characteristics are outlined in the table. Median overall survival (OS) was 15.9 months (m) (95% CI 14.7 – 18.1) since diagnosis of advanced disease (n=159). Patients with esophagogastric junction (EGJ) tumors had better OS compared to esophageal (HR 0.29 (95% CI 0.15-0.58) 20.1 vs 13.3 m p= 0.0003) or gastric (HR 0.48 (95% CI 0.26-0.86) 20.1 vs 15.9 m p=0.01). Survival analysis didn´t show statistically significant differences in OS regarding sex, HER2 status, ascites or signet ring cells. We found ESCAT I, II and III alterations in 52, 5 and 10 cases respectively. Most tier I (38) were HER2 overexpression/amplification, all received matched therapy with trastuzumab. Other were: MSI (10), TMB-H (3) and FRFR2 amp (1). Among Tier II: BCRA1 mut (1), BRCA2 mut (1) and EGFR amplification (3) and Tier III: PIK3CA mut (5), HER2 mut (3) and ATM mut (2). Table: 1582P

Conclusions

Our results indicate that young patients present poor prognosis features (localization, advanced stage, histology) but a significant number of them presented ESCAT I alterations, being candidates to receive a matched therapy as standard of care.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

A. Vivancos: Financial Interests, Personal, Advisory Board: Roche, Bristol Myers Squibb, Guardant Health, Bayer, Incyte; Financial Interests, Personal, Stocks/Shares: REVEAL GENOMICS; Financial Interests, Institutional, Research Grant, Preclinical Research Grant: Bristol Myers Squibb, Roche, Incyte. T. Macarulla: Financial Interests, Personal, Advisory Board: Ability Pharmaceutical, SL, AstraZeneca, Basilea Pharma, Batxer, BioLineRX Ltd, Celgene SLU, Eisai, IPSEN Pharma, Incyte; Financial Interests, Personal, Other, Direct research fund: Servier, Merck, Sharp and Dhome, Novocure, QED Therapeutics Inc, Roche, Sanofi-Aventis, Zymeworks; Financial Interests, Personal, Invited Speaker: Lilly, Janssen; Financial Interests, Institutional, Research Grant: Amc Medical Research, Armo Biosciences, Basilea, Biokeralty Research Institute, Merck Sharp & Dohme, Oncomed Pharmaceuticals, QED Therapeutics, VCN Biosciences, AbbVie Farmaceútica, Ability Pharmaceuticals, Agios, Amgen, Aslan, AstraZecena, Bayer, BeiGene, BioLineRX, Blueprint Medicines, Boston Biomedical, Bristol Myers Squibb (BMS), Cantargia, Celgene, Eisai, Erytech Pharma, F. Hoffmann-la Roche, FibroGen, Genentech, Hallozyme, Immunomedics, Incyte, Ipsen, Lab. Menarini, Lilly, Loxo Oncology, MedImmune, Merimarck, Millenim, Nelum, Novartis, Novocure, Pfizer, Pharmacyclics, Roche, Zymeworks; Non-Financial Interests, Member: American Society of Clinical Oncology - ASCO, “Sociedad Española de Oncología Médica” – SEOM, Sociedad Europea de Oncología Médica - ESMO. All other authors have declared no conflicts of interest.