This study investigates gastric cancer, gastrointestinal stromal tumors (GIST), esophageal cancer, pancreas cancer, hepatocellular cancer, biliary cancer, neuroendocrine, peritoneal mesothelioma, anal cancer, and colorectal cancer. The purpose is to collect and store normal and malignant tissue from patients undergoing surgery or biopsy for these conditions.

The study evaluates the creation of a database for collected tissues and blood samples, which will support future research. It will facilitate molecular studies by creating tissue microarrays for each cancer subtype, allowing for the investigation of molecular markers and their role in gastrointestinal cancers.

• Who can participate: Patients diagnosed with gastric cancer, esophageal cancer, pancreas cancer, liver cancer, biliary cancer, gastrointestinal stromal tumor, peritoneal mesothelioma, neuroendocrine tumor, anal cancer, or colorectal cancer who require surgical or diagnostic procedures are eligible.
• Study details: Participants will have tissue and blood samples collected during their surgical or diagnostic procedures. These samples will be stored for future research, which may include molecular testing to evaluate DNA mutations and protein expressions.