The aim of this study is to investigate urokinase Plasminogen Activator Receptor (uPAR) microexpression in gastroesophageal cancer (adenocarcinomas) both qualitatively and semi-quantitatively and to evaluate if it offers a possibility for future imagining purposes.

• Sections of the tumor tissue will be HE stained.
• Sections of the tumor tissue will be stained with an uPAR antibody for immunohistochemistry.
• Immunohistochemical staining against cytokeratin which colors cancer cells will be made to assist the observer in the evaluation of uPAR microexpression pattern.
• A semiqualitative scale corresponding to the level of uPAR expression will be made.
• Quantitative polymerase chain reaction will be used to validate the immunohistochemistry uPAR expression pattern.
• An electronic scoring system (digital pathology) will be trained to access the expression of uPAR in both tumor- and normal tissue.

Inclusion Criteria:

• Age ≥18 years old.
• Patients who underwent curatively intended surgery for gastroesophageal cancer
• Patients who underwent surgery after 01-01-2016.

Exclusion Criteria:

• Patients who applied for an exception from medical research at the "National Registry of Tissue Use."
• Patients with other histological subtypes than adenocarcinoma.