In order to define antigens that might be suitable as vaccines for pancreatic carcinoma, we investigated the composite expression of 10 cancer testis (CT) antigens (SCP-1, NY-ESO-1, SSX-1, SSX-2, SSX-4, GAGE, MAGE-3, MAGE-4, CT-7 and CT-8) by Reverse Transcriptase-PCR (RT-PCR) in fresh biopsies of human pancreatic adenocarcinoma, chronic pancreatitis and pancreatic carcinoma cell lines. While all CT genes were frequently expressed in cell lines derived from pancreatic cancer, no expression of MAGE-3, SSX-1, SSX-2, NY-ESO-1 and CT-7 was detected in fresh tumor biopsies, and MAGE-4 (1/52), SSX-4 (1/39) and CT-8 (2/41) were only rarely expressed. In contrast, HOM-TES-14/SCP-1 was expressed in 48% (29/61) and GAGE in 21% (13/61) of cases, respectively. One CT gene was expressed by 59% (75% in male, 46% in female patients; p ‫؍‬ 0.05) and 2 or more CT genes by 15% of the samples. SCP-1 protein expression correlated well with mRNA expression. While SCP-1 and GAGE were absent in normal pancreas, they were found in 2/8 (SCP-1) and 1/8 (GAGE) samples of chronic pancreatitis, respectively, supporting the concept of chronic pancreatitis as a premalignant condition. SCP-1 and GAGE represent promising candidates for vaccine development in pancreatic carcinoma. Whether SCP-1 and GAGE expression identify cases of chronic pancreatitis with a high risk of malignant transformation remains to be shown. © 2004 Wiley-Liss, Inc. Key words: cancer testis antigen; tumor rejection antigen; MAGE; GAGE; SSX; NY-ESO-1; specific immunotherapy; cancer vaccineDespite recent advances in surgery, 1 radiotherapy 2 and chemotherapy 3 of pancreatic cancer, the 5-year survival remains 3-5% for all stages. 4 Therefore, alternative therapeutic approaches are pursued. Of the latter, immunotherapy has the potential of a therapeutic tool that might be integrated into conventional surgical, radiotherapeutic and chemotherapeutic treatment modalities without significantly adding to therapy-associated toxicity.A prerequisite for the development of tumor-specific immunotherapeutic strategies is the existence and identification of tumor antigens, i.e., genes that are either exclusively or preferentially expressed in malignant tissues compared to normal tissues. According to their expression pattern and the specificity of the immune responses they evoke, antigens expressed by human neoplasms can be classified into different groups. 5 These include the so-called shared tumor antigens (e.g., the MAGE family), the differentiation antigens (e.g., tyrosinase), the products of viral genes (e.g., HPV-16), mutated genes (e.g., mutated p53), differentially spliced genes (e.g., restin 6 ), overexpressed genes and amplified genes (e.g., elF-4␥ 7 ) as well as common autoantigens that are expressed by the malignant cells of a tumor (e.g., U1 snRNP 5 ).In pancreatic cancer, only few tumor antigens are known and most of them are overexpressed in tumor cells, but will also be found at a certain level in normal human cells (e.g., CEA, Her-2/ neu, MUC-1, CA19-9, CA 242 and 17-1...