Frequencies of Porphyromonas gingivalis Detection in Oral-Digestive Tract Tumors

Mounting evidence suggests a causal relationship between specific bacterial infections and the development of certain malignancies. In this study, we examined the presence of Porphyromonas gingivalis(P. gingivalis) in oral-digestive tract tumours by immunohistochemistry (IHC) and PCR and analysed the correlation between P. gingivalis detection and clinicopathological characteristics and prognosis of oral and oesophageal carcinoma. The IHC results showed that the positive rates of P. gingivalis were 60.00%, 46.00%, 20.00%, 6.67%, and 2.86% in oral, oesophagus, cardiac, stomach, and colorectal cancer tissues, respectively. Likewise, PCR results showed rates of 56.00%, 42.00%, 16.67%, 3.33%, and 2.86%, respectively. The two methods were consistent, and the kappa value was 0.806, P<0.001. In addition, P. gingivalis expression was significantly correlated with lymph node metastasis and the clinical stages of oral and oesophageal cancer (P<0.05). The overall survival rate of the P. gingivalis undetected group (86%, 50%) was significantly higher than that of the P. gingivalis detected group (57%, 14%) for oral and oesophageal cancer, respectively. In conclusion, the detection rate of P. gingivalis showed a decreasing trend in oral-digestive tract tumours. Detection with P. gingivalis was associated with poor prognosis for oral and oesophageal cancer.