The periodontal infection may be a contributing factor to the development of gastric cancer

Self-reported tooth loss is highly prevalent in patients with gastric cancer, the second most common malignancy worldwide. Periodontal disease is characterized by loss of the periodontal ligament and alveolar bone, and is a major cause of tooth loss. The theories have been confirmed that chronic systemic inflammation and increased exposure to carcinogenic nitrosamines can increase the risk of cancer, and periodontal pathogens could induce the chronic inflammation. Poor oral hygiene and periodontal diseases may contribute to greater nitrosamine production.
The Hypothesis: We hypothesize that periodontal diseases might be an important risk factor for gastric cancer. Major pathogens of periodontal diseases may play a more direct role through local inflammatory responses and carcinogenic transformations in the development of gastric cancer.
Evaluation of the Hypothesis: It is possible that periodontal disease may be a marker of a type of immune function that has implications for tumor growth and progression in stomach. If periodontal bacteria indeed play an important role in the development of gastric cancer, the patients should be treated not only focused on the stomach disease itself but also the periodontal problems.