Angiotensinogen polymorphism is associated with risk for malignancy but not for oral cancer

Background: In light of the recently found contribution of angiogenic and inflammation-related factors to malignancies, this study investigated the possible association of the angiotensinogen gene (AGT) with increased risk of oral cancer. Materials and Methods: The M235T polymorphism, which influences AGT gene expression, was evaluated by restriction fragment length polymorphism analysis in the DNA samples of 163 German and Greek patients with oral squamous cell carcinoma (OSCC) and 124 healthy controls of equivalent gender, ethnicity and age. Results: No significant difference of the mutant (235T) allele, which results in higher AGT gene expression, was observed in the whole patient group in comparison with the normal controls. Similarly, compared to the controls no significant difference of either allele or carrier frequency was detected in almost every subgroup of patients. Only in the subgroup of patients with a positive family history of cancer was a significant increase of mutant T allele and carrier frequencies observed, compared to the controls (50% vs. 36.7% and 79.3% vs. 61.3%, respectively, p<0.05 in both cases). In this particular subgroup of patients the odds ratio for OSCC of TT homozygotes was 3.57 (CI 95% 1.2-10.62), while for the MT heterozygotes it was 2.41 (CI 95% 1.06-5.49). Conclusion: This study did not reveal an association of the AGT M235T polymorphism with oral oncogenesis, but certainly suggested a possible association of this specific polymorphism with other types of cancer. The present findings support a previous suggestion that the pathway of oral oncogenesis is probably based on angiotensin-converting enzyme and bradykinin interaction and not on AGT and angiotensin peptides.