HER2-positive locally advanced/metastatic gastric and/or gastroesophageal junction (GEJ) adenocarcinoma in Russia

Inclusion Criteria

• - Patients with locally advanced/metastatic gastric and/or gastroesophageal junction (GEJ) adenocarcinoma, with the diagnosis established between the 1st January 2022 and the 1st January 2023.
• - Patients with documented HER2+ status based on IHC score ± ISH status.
• - Patients have an adequate archival tumor sample and slides suitable for reassessment HER2 status by the reference laboratory.
• - Age ≥ 18 years at the time of inclusion.
• - Patients provided written consent allowing for data and samples to be used in the future and this study would be covered by the consent for future use in accordance with ICH GCP, GPP (Good Pharmacoepidemiology Practices) and local law prior to inclusion in the study. If the patient is deceased, a waiver may be accepted.