Objective To explore the potential correlation between traditional Chinese medicine (TCM) tongue characteristics and the progression of gastric cancer by analyzing the TCM tongue images of newly diagnosed gastric cancer patients with different TNM.

Methods This study is a multicenter prospective clinical study, 1056 newly diagnosed gastric cancer patients were selected as the research subjects, TCM physicians from multiple centers used standardized equipment to collect tongue image data during a fixed period. The tongue image data were analyzed using artificial intelligence to extract types of characteristics: tongue color, coating color, tongue body, tooth marks, cracks, punctate, tongue coating thickness, coating quality, and tongue moisture. Patients classified according to different TNM stage s (Ⅰ、Ⅱ、Ⅲ and Ⅳ), and the TCM tongue images of different stage s were analyzed and compared.

Results There were significant differences in the TCM tongue images of cancer patients with different TNM stage s. In terms of tongue color, both stage Ⅰ and stage Ⅱ were dominated by red tongues, while stage Ⅲ and stage Ⅳ had more red tongues, and the proportion of red, purple, and blue-purple tongues gradually increased with the progression of the; in terms of coating color, stage Ⅰ was dominated by white, while the other three stage s were dominated by yellow, but there was no significant difference between stage I stage Ⅱ, and both stage Ⅲ and stage Ⅳ were significantly different from stage Ⅰ (P ＜ 0.05). In terms of tongue coating thickness and tongue thickness, all four groups of patients were dominated by thick coating and large tongue, but the proportion of thick coating and large tongue in stage Ⅲ and stage Ⅳ patients was higher than that in stage Ⅰ and stage Ⅱ, and the proportion of thin coating decreased and the proportion of shed coating increased with the progression of the disease. In terms tooth marks, patients in stage Ⅰ and stage Ⅱ were mainly without or with mild tooth marks, while patients in stage Ⅲ and stage Ⅳ were mainly with severe tooth marks and there was a significant difference between the two groups of patients (P ＜ 0.05). Through logistic regression, it was found that high degree of tooth marks, pale white tongue color, yellow coating and gray-black coating, large tongue body, and shed coating were all risk indicators for the progression of gastric cancer (P ＜0.05 to P ＜ 0.01).

Conclusion The results of this study show that the tongue images of gastric cancer patients with different clinical stage s are different, and TCM tongue diagnosis as a non-invasive auxiliary tool can be used clinically as an indicator of gastric cancer staging and progression, has the potential to assess the severity of the disease and monitor the progression of the disease in cancer patients.