This study focuses on the discovery of protein biomarkers for the early diagnosis of gastric cancer and the development of corresponding detection methods. By employing advanced mass spectrometry-based proteomic technologies, the investigators conducted an in-depth analysis of a large cohort of clinical samples to identify specific protein biomarkers capable of accurately distinguishing gastric cancer patients from healthy individuals. The findings from this research are expected to facilitate the development of novel non-invasive or minimally invasive diagnostic approaches, thereby improving early detection, enhancing patient prognosis, and increasing survival rates.

Inclusion Criteria

Gastric cancer patients enrolled in this study must meet all of the following criteria:

1. Male or female, aged ≥18 and ≤95 years.
2. Histopathologically confirmed gastric cancer, as defined by the 2024 edition of the Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Gastric Cancer.
3. No prior anti-tumor treatment (including radiotherapy, chemotherapy, targeted therapy, or immunotherapy).
4. Availability of complete clinicopathological data and follow-up information.

Patients with precancerous gastric lesions must meet all of the following criteria:

1. Male or female, aged ≥18 and ≤95 years.
2. Histopathologically confirmed absence of gastric cancer.
3. Diagnosis consistent with precancerous gastric lesions as defined by the American Society for Gastrointestinal Endoscopy (ASGE, 2015 edition).
4. Availability of complete clinicopathological data and follow-up information.

Healthy controls must meet all of the following criteria:

1. Male or female, aged ≥18 and ≤95 years.
2. Histopathologically confirmed absence of gastric cancer.
3. No evidence of precancerous gastric lesions.
4. Availability of complete clinicopathological data and follow-up information.

Exclusion Criteria

Patients meeting any of the following conditions will be excluded:

1. History of prior malignancy or cancer treatment.
2. Presence of concurrent malignancies of other types.
3. Inability to tolerate gastroscopy.

The study recruits two main populations: patients with gastric cancer and non-gastric cancer participants. The latter group includes two subgroups: individuals with precancerous gastric lesions and healthy controls.