Relationship between ABO blood group antigens and Rh factor with breast cancer: A systematic review and meta-analysis

Breast cancer is a type of cancer that can affect both males and females, but it is widespread among women. Blood types may be associated with breast cancer, as many studies have reported on this relationship but rarely described it. The primary objective of our research is to summarize and analyze the available evidence to produce comprehensive and accurate information that can be used to make evidence-based decisions. Researchers searched for studies on breast cancer patients and ABO blood groups across four major databases: PubMed, Scopus, Web of Science, and Google. The outcomes of the studies were presented as a relative risk and odds ratio with a 95% confidence interval. Twenty-nine case-control studies with 13029 breast cancer patients. Blood type A was the most common blood type among patients. For blood type A, there was an association with breast cancer (OR = 1.18, 95% CI: 1.03-1.36). Blood types B, AB, and Rh factor showed no significant association with breast cancer (OR = 0.97, 95% CI: 0.86-1.11, OR = 1.05, 95% CI: 0.89-1.25, and OR = 1.14, 95% CI: 0.81-1.60 respectively) in compare to blood type A. This study highlights the potential of blood type A as a risk factor for breast cancer compared to blood type O. This relationship was insignificant for blood types B, AB, or Rh. Further studies are needed to understand the mechanisms behind the blood type and breast cancer correlation.