The core of this study lies in directly addressing the most pressing clinical uncertainty in the current field: For patients with advanced metastatic gastric cancer who have achieved significant radiological remission after conversion therapy, should the addition of radical surgical intervention on top of the best medical treatment bring clear survival benefits to these patients? Answering this question is of extreme importance and urgency, directly affecting the treatment decisions, quality of life, and survival outcomes of a large number of patients.
Age and Informed Consent: The age range is 18 to 75 years (inclusive), and the participant must voluntarily participate in this study and sign the patient informed consent approved by the ethics committee.
Pathological Diagnosis: Gastric or gastroesophageal junction (GEJ) adenocarcinoma confirmed by histological or cytological examination.
Disease Staging: Newly diagnosed, unresectable stage IV disease (according to the 8th edition of the AJCC staging system), confirmed by the multidisciplinary team (MDT) of the research center to be unable to undergo radical surgical resection. The types of metastasis include but are not limited to: unresectable distant lymph node metastasis (such as beyond the abdominal aorta trunk, supraclavicular lymph nodes, etc.); distant organ metastasis (such as liver, lungs, peritoneum, ovaries, etc.).
Has received 4-6 cycles of first-line standard conversion therapy. The treatment plan should be based on the latest clinical guidelines and molecular typing (such as fluorouracil/platinum double or triple drug chemotherapy, combined with anti-HER2 treatment (for HER2-positive patients) or immune checkpoint inhibitors (PD-1/PD-L1 inhibitors, such as when CPS ≥ 5 or MSI-H, etc.).
Pathological type: Other pathological types, such as squamous cell carcinoma, adenosquamous carcinoma, undifferentiated carcinoma, gastrointestinal stromal tumor (GIST), etc.
During the conversion therapy, disease progression (PD) was confirmed after assessment.
Previously received systemic anti-tumor treatment for advanced gastric cancer (except for conversion therapy).
Previously received radical radiotherapy for the stomach or metastatic lesions.