A screening method for gastric cancer by oral microbiome detection.

Gastric cancer is the second most common malig-nancy and one of the principal causes of cancer­related mortality worldwide. Early diagnostic and screening methods for gastric cancer are limited at present, most of them involving invasive procedures. We aimed to investigate the characteristics of the oral microbiome in gastric cancer individuals and to conduct a screening method for gastric cancer by oral microbiome detection. We used high­throughput sequencing to examine the total bacterial profile of saliva and plaque samples of 50 subjects, including 37 individuals with gastric cancer and 13 controls. The Venn diagram and species abundance clusters were generated from the data. The results indicated that the oral bacteria were more complex in patients with gastric cancer. Based on the characteristics of the oral microbiome in individuals with gastric cancer, a scoring system was designed to screen gastric cancer. In the present study, 36 out of 37 individuals in the gastric cancer group were identified as a high­risk population, giving a sensitivity rate of 97%. One out of 13 individuals in the control group was identified as a high­risk population, providing a false-positive rate of 7.7%. The scoring system we designed may be a potential method for screening suspected gastric cancer patients by oral microbiome detection. Further calibration of this scoring system is needed by recruiting a larger study population.

[An eight-year longitudinal study for caries status on primary and permanent dentitions in Beijing children].

OBJECTIVE: To study whether the caries status of the primary dentition correlated with status of the permanent in the same cohort over an eight-year period. To determine whether the caries status of the primary dentition can be used to predict caries in the permanent dentition. METHODS: A total of 362 children, 3 - 4 years old in the baseline study in 1992 were re-examined in 2000 based on WHO criteria and methods. RESULTS: Statistically significant associations were observed between the caries prevalence in primary and permanent teeth (P < 0.01) and between DMFT(s) and dmft(s) (P < 0.01). Children who had caries in the primary teeth were nearly three times more likely to have caries in the permanent teeth (RR = 2.6,95% CI = 1.4 - 4.7, P < 0.001). The highest sensitivity (93.9%) for prediction caries in the permanent dentition was found in caries presence on any of the eight primary molars, for which the relative ratio was 3.3 (95% CI = 1.8 - 6.1, P < 0.001) and the positive prediction value was 85.4%. CONCLUSION: The study determinate clearly that caries status in the primary teeth can be used as a risk indicator for predicting caries in the permanent dentition.