Real-world Effectiveness and Safety of Trastuzumab Deruxtecan in Patients With Locally Advanced or Metastatic HER2-positive Gastric or Gastroesophageal Junction Adenocarcinoma in China

Inclusion Criteria

• •1. Participants with pathologically diagnosed locally advanced unresectable or metastatic gastric cancer/gastroesophageal junction adenocarcinoma (GC/GEJA).
• •2. ≥18 years of age at the time of starting the first dose of T-DXd and signing informed consent form (ICF), capable of providing informed consent.
• •3. HER2-positive status (IHC 3+ or IHC 2+/ISH +).
• •4. Received prior anti-cancer treatment regimens according to National Medical Products Administration indication or clinical judgement of physician.
• •5. Decision to newly initiate T-DXd before study ICF signing. If the participants have started the first dose of T-DXd no longer than 21 days before enrollment, they could be enrolled if the signed and dated ICF could be obtained.