Abstract A024: ABO blood type and overall survival in patients with pancreatic adenocarcinoma: A systematic review and meta-analysis
Authors: Correa Tulio L , Cristalli Marcelo , Lage Bodour Danielian Pedro Luiz , Antunes Vanio L J , Fernandes Matheus Vanzin , Milioli Natalia Junkes , Martins Otavio C , Florencio de Mesquita Cynthia , Baraldo Stefano , Bockorny Bruno 
Published: September 2024

Abstract
Background/Aim: Recent studies have reported that blood group antigens influence the risk of pancreatic cancer. However, studies on the influence of ABO blood groups on the outcomes of pancreatic cancer have been controversial. Therefore, we aimed to perform a systematic review and meta-analysis to evaluate the association between ABO blood groups and the overall survival in patients with pancreatic adenocarcinoma. Methods: A systematic review of the literature was conducted using the PubMed/Medline, Cochrane Library, and Embase databases in June 2024. This review included observational studies published as complete articles that assessed overall survival or mortality in patients with pancreatic cancer with O blood group compared to non-O. Review Manager 5.1 was used for statistical analysis. Hazard ratios (HRs) with 95% CI were pooled across studies. A random-effects model was used for outcomes with high heterogeneity. In cases where significant heterogeneity was observed (I2 &gt; 40%), sensitivity analyses were conducted. Statistical significance was defined as a p-value &lt; 0.05. Results: Of the 1,624 entries initially identified, nine retrospective studies were included in this meta-analysis, comprising 4,965 individuals. Individuals with O blood type had no statistically significant difference in overall survival compared to the non-O group (HR 1.22; 95% CI 0.97 to 1.53; p = 0.09; I2 = 70%). However, sensitivity analysis revealed one study as the main source of heterogeneity, and its exclusion significantly modified the results favoring the O blood group (HR 1.32; 95% CI 1.13 to 1.54; p = &lt; 0.001; I2 = 10%). Patients with O blood type also had no statistically significant difference in overall survival compared to type A (HR 1.04; 95% CI 0.95 to 1.14; p = 0.43; I2 = 38%) and type B (HR 1.10; 95% CI 0.84 to 1.45; p = 0.49; I2 = 65%). Conclusions: ABO blood groups do not seem to be significantly associated with overall survival and mortality in individuals with pancreatic cancer. However, some analyses revealed significant heterogeneity between the studies. Additionally, a few studies were excluded from the plot because their results were reported in a manner that could not be integrated into a meta-analysis. Further multicenter prospective studies are still needed to validate our results.
Citation Format: Tulio L Correa, Marcelo Cristalli, Pedro Luiz Lage Bodour Danielian, Vanio L J Antunes, Matheus Vanzin Fernandes, Natalia Junkes Milioli, Otavio C Martins, Cynthia Florencio de Mesquita, Stefano Baraldo, Bruno Bockorny. ABO blood type and overall survival in patients with pancreatic adenocarcinoma: A systematic review and meta-analysis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A024.