Assessment of relationship of ABO blood groups in oral cance
India is a high-risk region for oropharyngeal cancer (OC) due to the high prevalence of tobacco, betel nut, and alcohol and accounts for 30% of all new cases of oral cancer annually.

Records of all 73 diagnosed cases of different types of OC and oropharynx patients were analyzed who reported in “Tobacco cessation center”' of the Institute. The patients' demographic details, blood groups, oral habits, and clinicohistological records were obtained from the medical records available in the hospital.

- OC incidence was 3.75 cases/year with a male-to-female ratio of 3.29:1. The mean age was 51.25 ± 13.6 years. The most common site of tumor presentation was the mandibular alveolar ridge.

- The combined use of tobacco/betel nut/alcohol constituted the major cause for the development of oral squamous cell carcinoma (OSCC).

- The majority of patients were presented in Stage II. Histopathological reports were suggestive of maximally well-differentiated OSCC.

- People with blood group A+ve had 3.22 times higher risk of developing OSCC compared to people of other blood groups.

Male: female ratio was reported higher than in most other studies. Mandibular alveolus was the most frequent site because most of the patients tend to keep the tobacco quid in the buccal vestibule with close proximity to the alveolus. The relative downregulation of glycosyltransferase that is involved in the biosynthesis of A and B antigens as seen in association with tumor development could be the reason for increased OC reported in blood group A subjects.

Annals of Maxillofacial Surgery