Development of Novel Gastric Cancer Screening and Diagnosis Technologies Using Tongue Imaging and Study of Tongue Image Changes Mechanisms

This study is exploring whether tongue imaging — photographing and analyzing the tongue — can be used as a new non-invasive screening tool for gastric (stomach) cancer. Traditional Chinese medicine has long associated tongue appearance with internal organ health; this study tests if there is scientific validity to that idea. **You may be eligible if...** - You are between 18 and 90 years old - You have been diagnosed with gastric cancer confirmed by tissue or cell testing - You have not yet received chemotherapy, radiation, immunotherapy, or other anti-cancer treatment for gastric cancer - You are willing to sign informed consent and attend follow-up **You may NOT be eligible if...** - You have already started cancer treatment - You have another active cancer at the same time - You are outside the 18–90 age range Talk to your doctor to see if this trial is right for you.