Method for determination of protein disulfide isomerase for in vitro diagnosis of colorectal cancer

The present invention relates to a diagnostic in vitro method for colorectal cancer by determining the presence of tumor marker protein disulfide isomerase in a biological sample from a patient suspected of suffering from colorectal cancer by using at least one monoclonal antibody anti- PDI directed against an epitope of PDI selected from epitopes of sequence SEQ ID No. 1, SEQ ID NO: 2 with a close aromatic amino acid in the three-dimensional structure of PDI and SEQ ID NO: 3, said method being used both in early diagnosis, screening, therapeutic follow-up, prognosis, as in the diagnosis of relapse in the case of colorectal cancer.