Background: Human ABO blood group type and the antigenic secretor status is hypothesized to cause oral diseases including oral cancer. Secretor status is the ability of individuals to secrete blood group antigens into body fluids. This study was aimed to evaluate the secretor status effect of ABO antigens of saliva in patients with oral cancers or oral potentially malignant disorders relative to healthy adults.
Methods: A systematic and comprehensive online search from inception to 28 April 2022 was carried out in Medline, Embase, PsycInfo and Emcare. The language was limited to English. Yielded records were screened by two independent reviewers at the title & abstract phase, and at full text screening. Studies investigating adults (≥18 years) with oral cancers or oral potentially malignant disorders compared to adults free of oral cancer were included to this study. Data were extracted according to a pre-identified inclusion and exclusion criteria. Methodological quality was assessed, and the findings were analyzed narratively. Meta-analyses were conducted to pool the odds of the non-secretor status of oral cancers and oral potentially malignant disorders compared to healthy adults.
Results: The search resulted a total of 34 studies from 3 databases. Nine duplicates were removed. During the title & abstract screening, 11 irrelevant studies were excluded. Twelve studies were screened during the full text screening, and 8 articles were eligible to be included in the final analysis. A pooled odds ratio (OR) of 3.80 (95%CI, 1.53 – 9.44) was estimated when pooled 1254 oral cancers and oral potentially malignant disorders patients compared to 666 healthy adults.
Discussion and Conclusion: The odds of being a non-secretor is approximately 3.8 times higher in patients with oral cancers and oral potentially malignant disorders compared to healthy adults. Lack of ABO blood group antigens in body fluids of non-secretors, are more exposed to exogenous antigens than secretors. The host-parasite interactions of secretors and non-secretors underlying the oral cancer and other diseases may evidence to support or refuse them. The relationship of ABO blood type with the risk of getting oral cancer is at an inconclusive state. The findings warrant use of non-secretor status as a non-expensive early screening test for oral cancers or oral potentially malignant disorders.