Early-onset oesophagogastric adenocarcinoma: Clinicopathological characteristics and outcomes from a ten-year tertiary centre experience: A retrospective cohort study.

BACKGROUND: The incidence of early-onset oesophageal, junctional, and gastric adenocarcinoma, collectively known as early onset (EO) oesophago-gastric adenocarcinoma (OGA) is rising worldwide, yet its clinicopathological characteristics and oncological outcomes remain incompletely defined. This study aimed to compare the clinical profile, treatment pathways and outcomes of patients with early-onset (<55 years) and late-onset (LO) (≥55 years) OGA. METHODS: A retrospective cohort study was conducted at a UK tertiary oesophago-gastric cancer centre (2014-2025). Clinicopathological features along with postoperative outcomes and survival metrics in those patients undergoing curative-intent resection were analysed. Survival was estimated using Kaplan-Meier analysis and compared by log-rank testing. RESULTS: Among 936 patients with OGA, 138 (14.7%) patients had EO disease compared with 798 (85.3%) patients who had LO disease. The proportion of EO OGA patients increased significantly from 11.5% (60/522) to 18.9% (78/414) over the study period (p = 0.0022). Surgery with curative intent was offered to 54.3% of EO patients versus 58.8% of LO patients (p = 0.38). EO patients had a significantly lower comorbidity burden (18.7% vs 46.3%, p < 0.00001); were more frequently female (30.4% vs 18.9%, p = 0.003); and presented more often with advanced-stage disease (stage III-IV, p = 0.018). Diffuse histology predominated in EO gastric cancers compared to LO gastric cancers (64.3% vs 43.2%, p = 0.07), with signet-ring features present in 66.7% of EO cases and 85% of LO. Postoperative outcomes were broadly comparable; however, EO patients had shorter ICU stays (6.5 vs 9.4 days, p = 0.0015) in oesophageal adenocarcinoma and lower pneumonia rates in gastric adenocarcinoma (10.7% vs 40.3%, p = 0.00084). Despite comparable post-operative pathological stage and treatment, EO disease was associated with significantly inferior disease-free survival (gastric: p = 0.0033; oesophageal: p = 0.026), while overall survival was similar. Recurrence patterns differed significantly (p = 0.00028), with EO gastric cancers demonstrating a markedly higher rate of peritoneal dissemination (50.0% vs 26.3%). CONCLUSIONS: EO OGA represents a distinct entity, characterised by a higher prevalence of diffuse histology and a relative female predominance compared to its LO counterpart. The rising incidence observed in our cohort is concerning and mirrors global trends reported in recent studies, with EO patients more frequently presenting at an advanced stage of disease. Of particular concern, this patient group demonstrates inferior post-operative disease-free survival despite lower comorbidity burden and receipt of equivalent treatment regimens. As such, they appear unable to derive the survival advantage that younger age might otherwise be expected to confer. These findings highlight the need for tailored preventive, diagnostic and therapeutic strategies for this emerging patient population.