ECP 2023 Abstracts

S107 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 distant metastasis and tumour stage with respectively p value 0.005 and 0.007. There was an inverse correlation with vascular invasion (0.052), perineural invasion (0.01) and carcinomatous lymphangitis (0.053). Positive Cyclin D1’tumours were associated with better patient survival at 5 years (p=0.03). Conclusion: The prognosis value of Cyclin D1 labelling was subject of discussion in CCR. Our results did not match with data based; we did not find a lot of series like us. Some authors explained these results by the fact that cyclin D1 induces apoptosis in tumour cells and therefore has a suppressive effect on tumour growth. PS-17-015 Oesophageal adenocarcinoma heterogeneity in clinicopathology and prognosis: a single-centre longitudinal cohort study of 146 patients over a 20-year period Q. Huang*, E. Lew, Y. Cheng, S. Shinagare, V. Deshpande, D. Wiener, J. Gold, H. Weber *Beth Israel Deaconess Medical CTR, USA Background & objectives: Recent clinical and genomic stud- ies suggest that oesophageal adenocarcinoma (EAC) is heteroge- neous and can be divided into true (tEAC) and probable (pEAC) groups. We investigated and compared clinicopathologic and prognostic features between those two groups of EAC patients. Methods: We identified 146 consecutive EAC patients treated at our centre over a 20-year period. Tumours with epicentres 2 cm beyond the gastroesophageal junction (GEJ) were assigned to the tEAC group (N=63), while tumour epicentres within 2 cm, but not crossing the GEJ were allocated to the pEAC group (N=83). Clinicopathologic and prognostic features were compared between the two groups. Results: All patients were elderly male (median age: 70 years) and over 98.6% were White. No significant difference between the two groups was found in gastroesophageal reflux disease, obesity (BMI 27.8), comorbidities, and being diagnosed during endoscopic surveil- lance. However, compared to pEAC patients, tEAC patients had a lower frequency of cases with no known history of Barrett’s oesophagus (p=0.053) but a higher prevalence of hiatal hernia (p=0.003), smaller tumour size (p=0.007), higher prevalence of common adenocarci- noma histology (p=0.001), early stage disease (p=0.012), and better 5-year overall survival (34.9 months versus 16.8 months in pEACs) (p= 0.043). Conclusion: Determining tumour epicentre location, using clinical, radi- ologic, endoscopic, surgical, and pathologic studies, demonstrates that tEAC patients had a higher prevalence of hiatal hernia, history of Bar- rett’s oesophagus, smaller tumour size, common adenocarcinoma type, early-stage disease, and better outcomes, compared to pEAC patients. Precise sub-classification of EAC patients based on tumour epicentre location allows the distinction of these two groups of EAC patients with different clinicopathologic and prognostic characteristics, which may help improve clinical management and translational research strategies. PS-17-016 Lymphovascular invasion in ESD specimens and its clinical significance J.M. Kim*, J.H. Sohn, M. Cho, The Gastrointestinal Pathology Study Group of Korean Society of Pathologist *Inha University Hospital, Republic of Korea Background & objectives: The authors investigated the frequency and significance of LVI in ESD specimens and tried to identify the clinicopathologic factors predicting LVI prior to the ESD. Methods: Total number of cases was 737 ESD specimens from 712 patients. The clinicopathologic factors analysed were age, gender, tumour location, tumour size, ulcer, differentiation, and depth of invasion. Results: LVI was observed in 32 cases (4.3%). The age, tumour size, differentiation, depth of invasion were correlated with LVI (p<0.04). The groups ≤2cm vs >2cm showed different risk of LVI (p=0.02), but groups ≤3cm vs >3cm did not (p=0.151). The incidence of LVI in LP, MM, SM1 and SM2 cancers were 0.3% (1/368), 1.2% (3/250), 20.0% (13/65), and 27.8% (15/54), respectively. Confidence interval was more acceptable in LP-MM-SM1 group vs SM2 group rather than LP-MM group vs SM1-SM2 group. The cases satisfying absolute or extended indication, LVI was observed in 1 (0.2%), and 12 (5.6%) cases, respectively. After surgery, lymph node metastases were identi- fied in 2 cases (4.2%, 2/48). Conclusion: This study will be useful to plan the treatment policy of gastric cancer patient who will undergo the ESD. PS-17-017 Tyrosine 42-phosphorylated RhoA expression is associated with aggressive behaviour in gastric cancer J. Kim*, J. Jung, J. Park *Department of Pathology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea Background & objectives: Wnt/β-catenin signalling pathway is commonly activated in gastric cancer. Tyrosine42-phosphorylated (p-Tyr42) RhoA induced by radical oxygen and Wnt3A is bound to β-catenin and transported into nucleus. We investigated the p-Tyr42 RhoA expression in gastric cancer and assessed its clinicopathologi- cal significance. Methods: Expression of p-Tyr42 RhoA was examined using immuno- histochemical staining on tissue microarrays consisting of 312 gastric cancer cases. Immunohistochemical expression was evaluated by two pathologists and used to compare clinicopathologic parameters and patients’ prognostic outcomes. Results: Cancer cells frequently showed high p-Tyr42 RhoA expression than normal gastric cells (p<0.001). High p-Tyr42 RhoA expression was associated with advanced gastric cancer (p<0.001), high grade (p<0.001), diffuse type (p<0.001), large tumour size (≥5 cm, p=0.035), lymph node metastasis (p=0.005), and high stage (p=0.035). Poorly differen- tiated tumours of intestinal-type had a tendency of high p-Tyr42 RhoA expression (p=0.048). In survival analysis, patients with high expres- sion displayed shorter disease-free survival (DFS) time than those with low expression (p=0.014). In intestinal-type cancer, patients with high p-Tyr42 RhoA expression had significantly worse DFS than those with low expression (p=0.019), however in diffuse-type cancer the expression did not relate to DFS (p=0.708). Conclusion: These findings suggest that p-Tyr42 RhoA is associated with aggressive biologic behaviour. P-Tyr42 PhoA may have value as a prog- nostic marker and a potential target molecule for gastric cancer treatment. PS-17-018 Autoimmune gastritis: is it really rare to see incomplete intestinal metaplasia? K. Kolçak*, G. Menetlioğlu, Ç. Ataizi Çelikel *Marmara University Pendik Hospital, Turkey Background & objectives: Recently it has been postulated that gastric adenocarcinoma (GACa) risk in autoimmune gastritis (AIG) is likely to be H. Pylori (HP)-related. Besides, the presence of incomplete intesti- nal metaplasia (IM) is controversial in HP (-) AIG. This study examines IM, atrophy and dysplasia in HP(-) AIGs. Methods: Between 2012 and 2022, gastric endoscopic biopsies with AIG were retrospectively collected and re-evaluated. Among 89 clini- cally verified cases, just 43 antiparietal antibody positive and HP(-) AIG cases were included in the study. Histopathological evaluation focused on the degree of inflammation, atrophy, and IM in accordance with Sydney