Page 55 - MI-2-1

Microbes & Immunity ABO blood type and cancer risk: A complex relationship

included combinations of keywords such as “ABO blood
group,” “cancer risk,” “oncology,” and specific cancer types
(e.g., breast, colorectal, lung, and prostate cancer).

Studies that provided original data or meta-analyses
linking ABO blood group phenotypes with cancer
incidence or susceptibility were included, particularly those
presenting significant findings, large sample sizes, or critical
insights into the potential mechanisms underlying this
association. Studies unrelated to cancer or those that lacked
clear ABO blood group data were excluded. Each article
was reviewed for quality, relevance, and methodological
rigor. Special attention was given to studies that controlled
for confounding variables such as age, sex, lifestyle factors,
and comorbidities. The results of the selected studies were
analyzed thoroughly to assess the strength of the evidence
Figure 2. Association between ABO antigens and cancer 8 connecting the ABO blood group with cancer risk and to
Abbreviation: VWF, von Willebrand factor.
identify patterns or inconsistencies across different types
of cancer. This methodology allowed for a comprehensive
antigens to promote the spread and progression of evaluation of the current understanding of the role of the
malignancy. 35,36 In addition, glycosylation can direct ABO blood group in cancer development.
conformational changes in proteins such as epidermal
growth factor receptors or alter the immune surveillance 3. Some major cancers associated with the
ability of immune cells such as natural killer cells that ABO blood group
promote malignancy. 37
Association of different blood types and its association
1.1.3. Adhesion molecules with the development of different cancers are shown in
Similarly, the relationship between ABO variants and Table 1.
circulating levels of adhesion molecules (intercellular
adhesion molecule-1 [ICAM-1], E-selectin, and P-selectin) 3.1. Gastric cancer
has provided a background that supports the influence Gastric cancer comprises 7% of all cancers globally.
of ABO in tumorigenesis, as these molecules are pivotal Studies have shown a stronger association between A and
regulators during chronic inflammation and recruitment of AB blood groups and gastric cancers. For example, the A
immune cells. A reduced level of ICAM-1 in patients with blood group showed an odds ratio (OR) of 1.13 and a 95%
8
the non-O blood group (specifically the A blood group) confidence interval (CI) of 1.02 – 1.24, and the AB blood
than in those with the O blood group is assumed to promote group shared an OR of 1.18 and a 95% CI of 1.02 – 1.36.
45
metastasis that causes a decrease in survival in patients with These ORs indicate a positive association between the A
cancer and non-O group and favors prognosis in patients and AB blood groups and the risk of gastric cancer, with
with the blood group O. 38-43 Because the blood group these groups having slightly higher odds of developing the
polysaccharides expressed on the cell surface of metastatic disease. The CIs for both blood groups were narrow and >1,
cancer cells function as cell adhesion molecules, a correlation meaning that the associations were statistically significant
was found between blood group antigen expression in tumors and not likely due to random variations. Recently, the
and metastasis and prognosis for various malignancies, Chi-squared value (χ = 4.708, P < 0.001) reported by Yu
2
including colon, breast, and prostate cancer. 44 et al. demonstrated a significant relationship between the
46
A blood group and gastric cancer development. Similarly,
2. Methodology Rummel and Ellsworth found that the A blood group
17
Google Scholar, PubMed, Research 4 Life, and Web of exhibited a greater risk of gastric cancer. The specific
Science were systematically searched to identify relevant blood type antigen (e.g., Lewis-b antigen), the result of
research papers published before January 2023. The blood type genes at 19q13, was found to mediate the
search strategy was designed to capture peer-reviewed attachment of Helicobacter pylori to the human gastric
articles and comprehensive reviews that investigated the mucosa, a causative agent in chronic active gastritis, in a
relationship between the ABO blood group and the risk study on the association between the ABO blood group
of developing common cancers. Specific search terms and gastric cancer. 47,48

Volume 2 Issue 1 (2025) 47 doi: 10.36922/mi.3267