Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 17 4 2023 10 14 275 280 Hosein Jodat 1) Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2)Department of Laboratory Sciences, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Javad Jodat 1)Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2)Department of Laboratory Sciences, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Ali Khodadadi 1) Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2)Cancer Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Abdolhassan Talaiezadeh 1)Cancer Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2)Department of Surgery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Nazanin Joudaki 1)Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran 2)Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran Ali Asadirad 1)Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2)Cancer Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2022 12 08 2023 09 05 Background: Colorectal cancer, a solid tumor with a high prevalence, contributes significantly to annual mortality rates. Various factors, including blood groups, may influence cancer risk. Multiple studies have suggested a potential connection between ABO and Rh blood groups and colorectal cancer risk. This study aims to investigate the role of ABO and Rh blood groups as risk factors in colorectal cancer patients. Materials and Methods: We conducted a retrospective study involving 71 colorectal cancer patients diagnosed between 2018 and 2020 in Khuzestan province, Iran, with known ABO blood types. Large-scale data from 29,922 blood donors in Khuzestan served as the healthy population control. The study analyzed the distribution of ABO blood groups among the blood donors. Results: Our findings revealed that the distribution of blood groups among colorectal cancer patients was as follows: O (31.0%), A (29.6%), B (29.6%), and AB (9.8%). However, our analysis did not establish a significant association between colorectal cancer risk and ABO antigens (P-value = 0.636) or Rh blood group (P = 0.198). Additionally, no significant differences in ABO blood types were observed concerning gender (P = 0.802), cancer type (P = 0.338), or tumor type (P = 0.207) among colorectal cancer patients. Conclusion: This study does not support a significant correlation between ABO and Rh blood groups and the risk of colorectal cancer, nor does it find associations with cancer type or tumor type. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/1954 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/1954/1003