Abstract: PURPOSE: To explore the relationship between ABO blood type and oral and maxillofacial malignancy in Chongqing area. METHODS: A total of 1054 patients with oral and maxillofacial malignant tumors diagnosed in the Stomatological Hospital of Chongqing Medical University in the past five years were selected as the research subjects, and the blood types of the healthy people were examined as the control group. SPSS 22.0 software package and Chi-square test were used to verify the correlation between the groups. The OR values of oral and maxillofacial malignancy of different blood types were compared among patients of three major cancers (squamous cell carcinoma, adenoid cystic carcinoma, mucoepidermoid carcinoma), so as to judge the relative risk of oral and maxillofacial malignant tumors of each blood type. RESULTS: The distribution of blood type in oral and maxillofacial malignancy patients was as follows: O(4.2%)>A(32.8%)>B(24.6%)>AB(8.4%), there was no significant difference in blood types between the patients and the controls. Patients with blood type O were easier to develop mucoepidermoid carcinoma compared with patients with other blood types (P<0.05, OR=2.09, 95%CI=1.04~4.17). In addition, the distribution of blood type of patients with mucoepidermoid carcinoma was significantly different from the control group. Males with blood type O were different from males with other blood types, which were more susceptible to adenoid cystic carcinoma and mucoepidermoid carcinoma (P<0.05, OR=3.06/3.06, 95%CI=1.31~7.12). CONCLUSIONS: There is certain relationship between the occurrence of oral and maxillofacial malignancy and ABO blood type in Chongqing area. The population of O blood type is easier to develop mucoepidermoid carcinoma while males with O blood type are more likely to develop adenoid cystic carcinoma and mucoepidermoid carcinoma.

Key words: Oral and maxillofacial, Malignant tumor, ABO blood type