Ductal adenocarcinoma

Abstract

Pancreatic adenocarcinoma is a lethal cancer, being the ninth most common malignancy but the fourth most common cause of cancer death in the USA (Jemal et al. 2010). Of the 44,030 cases predicted in the USA for 2011, 37,660 patients are expected to die from their disease (Siegal et al. 2011). Pancreatic cancer is the tumor most likely to be spread beyond the organ of origin at the time of diagnosis. For all patients presenting with pancreatic adenocarcinoma, approximately 45% already have metastatic (stage IV) disease at the time of diagnosis, 40% have locally advanced tumors that involve the peripancreatic vessels to such an extent that resection is not possible, and approximately 15% present with surgical lesions. Survival is abysmal and measured in terms of months. Even for patients who are surgically resectable, 5-year survival after successful (curative) pancreaticoduodenectomy or distal pancreatectomy is approximately 20% (Yoon et al. 2011; Conlon et al. 1996). However, survival after resection increases to 75% for resected stage I disease (Tsuchiya et al. 1986a, b). Therefore, an important goal of imaging is to improve detection in patients with early stage disease, recognizing that while most stage I tumors are small, not all small tumors are stage I (Yoon et al. 2011; Chiang et al. 2009; Egawa et al. 2004; Shimada et al. 2006). This finding is due, at least in part, to the propensity of pancreatic adenocarcinomas to extend along perineural pathways to the extrapancreatic tissues (Deshmukh et al. 2010). In addition to being the primary mode of detection, cross-sectional imaging plays a major role in the assessment of suitability of an individual patient for potential surgical resection. In recent years, with the advent of more successful adjuvant and neoadjuvant therapies for pancreatic adenocarcinoma patients, serial imaging also has a role in tumor response assessment (Brennan et al. 2007).