Pancreatic Adenocarcinoma Staging in the Era of Preoperative Chemotherapy and Radiation Therapy

Abstract

Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumor often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemotherapy and radiation therapy in patients with nonmetastatic PDA. The main advantage of this strategy is better selection of patients likely to benefit from curative-intent surgery through the achievement of negative resection margins. Patients with rapidly progressive disease are identified and are spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can downstage tumors classified as locally advanced at initial imaging studies to resectable tumors. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumor-vessel contact, are not valid after neoadjuvant therapy.

Prognostic factors following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma

“…2 Others reported that a combination of CTx and radiotherapy was the most significant positive prognostic factor for survival. 5,26,27 In this study, we had 4.3% perioperative mortality which is nearly similar to what was reported in other studies. 2,4,6,13,21,28 Seppänen et al, reported perioperative mortality 2.1%, and 5-year survival 22% after PD for PDAC.…”

Imaging diagnosis and staging of pancreatic ductal adenocarcinoma: a comprehensive review

“…CT is the modality of choice for the assessment of vascular invasion with a specificity of 82-100% and sensitivity of 70-96% [37][38][39][40]. Biphasic pancreatic CT, performed with thin slice thickness (< 3 mm, preferably 0.5-1 mm if available) and multi-planar reformatting, is the optimal technique to evaluate the peripancreatic arteries and veins during the pancreatic and portal venous phases, respectively [9].…”

“…A borderline resectable (BR) tumor is an entity which fails to be classified under these two categories. This category is variable among different institutions particularly in defining the criteria related to venous invasion due to variations in vascular reconstruction surgeries [40]. In 2016, the International Association of Pancreatology (IAP) attempted to promote an international consensus to define borderline resectable PDAC (BR-PDAC) and included (1) anatomical, (2) biological, and (3) conditional criteria (Table 1) [50].…”

Response to Preoperative Therapy in Localized Pancreatic Cancer

“…The problem was identified clearly as early as 2001, with a study that suggested that CT after preoperative therapy seemed to underestimate the possibility of resecting a tumor to negative margins (29). The peculiar nature of the PDAC extensive and dense fibrous stroma, which after chemotherapy is often associated with a persistence of fibrosis tissue that prevents the tumor from shrinking on imaging-even after the destruction of cancer cells-seems to be the main responsible for this perceived lack of accuracy (30).…”