Background In the Hokusai VTE Cancer study, the risk of major bleeding was 2.9% higher in the edoxaban group compared with the dalteparin group, mainly due to more gastrointestinal bleedings in patients with gastrointestinal cancer. The identification of risk factors for gastrointestinal bleeding may help to guide the use of DOACs in these patients. Objectives To evaluate risk factors for gastrointestinal bleeding in patients with gastrointestinal cancer receiving edoxaban. Patients/Methods In this nested case‐control study in patients with gastrointestinal cancer randomized to edoxaban in the Hokusai VTE Cancer study, cases (patients with clinically relevant gastrointestinal bleeding during treatment) were randomly matched to three controls (patients who had no gastrointestinal bleeding). Data for the 4‐week period prior to bleeding were retrospectively collected. Odds ratios (ORs) were calculated in a crude conditional logistic regression model and a multivariable model adjusted for age, sex, and cancer type. Results Twenty‐four cases and 64 matched controls were included. In the multivariable analysis, advanced cancer, defined as regionally advanced or metastatic cancer (OR 3.6, 95% CI 1.01–12.6) and low hemoglobin levels (OR 4.8, 95% CI 1.5–16.0) were significantly associated with bleeding. There was no significant difference in patients with resected tumors (OR 0.4, 95% CI 0.1–1.4), or in patients on chemotherapy (OR 1.3, 95% CI 0.5–3.5). Conclusion Advanced cancer and low hemoglobin levels were associated with an increased risk of gastrointestinal bleeding in patients with gastrointestinal cancer receiving edoxaban. We were unable to identify other risk factors, mainly due to limited statistical power.

TPS4155 Background: GC represents a worldwide problem; radical surgery remaining the gold standard of curative treatment. In the West, even with peri-operative chemotherapy, 5-year survival rate is approximately 40%. GC is a heterogeneous disease, well characterized by different molecular classifications, all having in common the role of the immune system and a T-cell inflamed phenotype across all subtypes. The anti-PD-L1 Av antibody has demonstrated efficacy in GC with response rates of around 10% in the refractory setting. The addition of other immune checkpoint inhibitors to chemotherapy have demonstrated efficacy in the metastatic setting. The combination of Av to perioperative chemotherapy may increase pathological responses by a synergistic effect, and then improving the survival (OS). Methods: The MONEO is an open-label, non-randomized, multicentric, phase II study that explores the combination of Av plus peri-operative FLOT (docetaxel, oxaliplatin, fluorouracil/leucovorin) in resectable GC pts. EudraCT 2019-000782-21; ClinicalTrials NCT03979131. Main inclusion criteria require pts with histologically proven GC, stage Ib (T1N1 only) - IIIC (7th AJCC Ed), available paraffin block from diagnosis and surgery, evaluable disease (RECIST 1.1) amenable to radical surgery. Significant comorbidities and active autoimmune diseases are excluded. Treatment consists of surgery with 4 peri-operatory cycles of FLOT + Av, followed by Av up to one year. The primary objective is the pathological complete response (pCR) rate, compared to historical data. Secondary objectives include OS, disease-free survival, R0 resection rate, tolerability and biomarker analysis. Key point is the comprehensive biomarker analysis from tissue and blood samples (pathological immune response, TCR clonality, immune contexture characterization, immunodynamic monitoring). Statistics for an estimated 33% pCR (historical 16%), 82% power, 0.1 one-side type I error. 37 pts will be recruited from 10 Spanish centers. The sponsor is Vall d'Hebron Institute of Oncology (VHIO), principal investigators Dr. Melero and Dr. Alsina. In compliance with the Helsinki Declaration. At a data cut-off day of 5th of February 2021, 38 patients have been enrolled, 27 of them have had the surgery. Although the difficulties during the COVID19 pandemia, only two patients had been withdrawn from the study. Clinical trial information: NCT03979131.

AE 0.15, with a substantial association, and between tests was K ¼ 0.33 AE 0.13, with a moderate association, regarding the Landis Koch scale. In all cases, the comparisons with Chi-square tests were significantly associated, however, the case definition vs test showed a lower percentage of false positive, when comparing test vs test. These results suggest that integrating the results of different tests into a single case definition can improve the diagnosis of H. pylori infection. Conclusions:It is concluded that the case definition is more precise in identify an H. pylori infected patient than the analysis of each diagnostic test separately, which suggests the usefulness of joint diagnostic tests as an important diagnostic tool for preventing the development of advanced gastric lesions in the sample.

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