Combining conventional and stroma-derived tumour markers in pancreatic ductal adenocarcinoma.

A lack of disease-specific symptoms and good tumour markers makes early detection and diagnosis of pancreatic ductal adenocarcinoma (PDAC) challenging. To analyse the tissue expression and circulating levels of four stroma-derived substances (type IV collagen, endostatin/type XVIII collagen, osteopontin and tenascin C) and four conventional tumour markers (CA 19-9, TPS, CEA and Ca 125) in a PDAC cohort. Tissue expression of markers in normal pancreas and PDAC tissue was analysed with immunofluorescence. Plasma concentrations of markers were measured before and after surgery. Patients with non-malignant disorders served as controls. The conventional and stromal substances were expressed in the cancer cell compartment and the stroma, respectively. Although most patients had increased levels of many markers before surgery, 2/12 (17%) of patients had normal levels of Ca 19-9 at this stage. High preoperative endostatin/type XVIII collagen, and postoperative type IV collagen was associated with short survival. Neither the pre- nor postoperative levels of TPS, Ca 125 or CA 19-9 were associated to survival. PDAC is characterized by an abundant stroma. These initial observations indicate that the stroma can be a source of PDAC tumour markers that are found in different compartments of the cancer, thus reflecting different aspects of tumour biology.