Tumor markers in the diagnosis of pancreatic carcinoma

The difficulty in an early diagnosis of pancreatic cancer is in the absence of early symptoms due to lower limit of detection of the actual imaging techniques. Clinical symptoms like weight loss, abdominal pain and jaundice indicate an advanced cancer stage. Today 50% of pancreatic tumors are diagnosed in advanced metastatic stage and only 20-30% show resectable cancer. Ultrasound and determination of a mucine like antigen as CA 19-9, CA 50 and CA 195 seem to allow an earlier diagnosis with a higher rate of resective surgery and a prolonged survival for these patients. The mucines are high molecular weight glycoproteins consistent of a backbone protein to which oligosaccarides are attached. The linkage of carbohydrate to the peptide is termed O-glycosidic and involves the hydroxylic groups of serine or threonine with N-acetylglucosamine. Only the backbone proteins are genetically determined (genes MUG). The gangliosides are the same or derivative of Lewis antigen. CA 19-9, CA 50 and CA 195 are assays directed to different epitopes probably present on the same mucinous antigen. These epitopes are not present in different mucines as CA 15-3, CA 125 and TAG 72. Recently other two mucines are emploied CA 242 and CAM 17.1 but they are not better than CA 19-9. The use of a "triplet" of tumor markers as CA 19-9, CA 125 and CEA is the best diagnostic tool for cancer of pancreas in an "integrated" use with ultrasonographic evaluation of the lesion. CA 19-9 permits differential diagnosis from neuroendocrine tumor or pancreatitis, the values of CA 125 and CEA are useful in the evaluation of the stage, resectability and prognosis of pancreatic cancer. The recent use of CA19-9 for the evaluation of radiochemotherapy in preoperative management of the patient is a mode of a well known application of tumor markers in a kinetic evaluation of the tumor for the radicality of therapy, follow-up, recurrence and the effectiveness of the palliative therapy.