Current and future trends in early detection of pancreatic cancer: Molecular targets and PET probes

Early detection of pancreatic cancer has been a long-standing challenge in determining prognosis and management of the deadly disease. Although the incidence of pancreatic cancer is low (2% of all malignancies), it is the fourth leading cause of deaths attributable to cancer in the U.S. A major cause for the high mortality rate, which exceeds 85%, is the difficulty in diagnosing the disease early in its development. The relative lack of reliable diagnostic tools to screen patients who are asymptomatic prior to the aggressive progression of disease has been the primary contributing factor in the high mortality rate in this patient population. Indeed, 80-90% of patients with pancreatic cancer have relatively small unresectable tumors at the time of diagnosis. Therefore, there is an unmet need for a highly sensitive diagnostic imaging modality to detect early-stage pancreatic cancer, as this may save the lives of many thousands of patients. Many literature reviews have been published on various aspects of pancreatic cancer, including biology, screening, and therapy; however, limited information is available on early detection, especially the use of highly sensitive modalities such as positron emission tomography (PET). Current [¹⁸F]FDG/PET imaging combined with CT (PET/CT) lacks the necessary sensitivity and specificity for detection of small lesions (∼2-3 mm) of pancreatic cancer that may be resectable and curable. Furthermore, accumulation of [¹⁸F]FDG in inflammatory tissue is a major problem; therefore, an appropriate PET tracer that is both highly sensitive and specific for carcinoma is necessary for PET imaging of early stage pancreatic cancer. This review focuses on early detection of pancreatic cancer by PET, including new targets and the development and application of new PET tracers.