Preoperative staging and evaluation of resectability in pancreatic ductal adenocarcinoma

Abstract

Background: Cancer of the pancreas is a common disease, but the large majority of patients have tumours that are irresectable at the time of diagnosis. Moreover, patients whose tumours are clearly beyond surgical cure are best treated non-operatively, if possible, by relief of biliary obstruction and percutaneous biopsy to confirm the diagnosis and then consideration of oncological treatment, notably chemotherapy. These facts underline the importance of a standard protocol for the preoperative determination of operability (is it worth operating?) and resectability (is there a chance that the tumour can be removed?). Recent years have seen the advent of many new techniques, both radiological and endoscopic, for the diagnosis and staging of pancreatic cancer. It would be impracticable in time and cost to submit every patient to every test. This review will evaluate the available techniques and offer a possible algorithm for use in routine clinical practice.

Discussion: In deciding whether to operate with a view to resecting a pancreatic cancer, the surgeon must take into account factors related to the patient, the tumour and the institution and team entrusted with the patient's care. Patient-related factors include age, general health, pain and the presence or absence of malnutrition and an acute phase inflammatory response. Tumour-related factors include tumour size and evidence of spread, whether to adjacent organs (notably major blood vessels) or further afield. Hospital-related factors chiefly concern the volume of pancreatic cancer treated and thus the experience of the whole team. Determination of resectability is heavily dependent upon detailed imaging. Nowadays conventional ultrasonography can be supplemented by endoscopic, laparoscopic and intra-operative techniques. Computed tomography (CT) remains the single most useful staging modality, but MRI continues to improve. PET scanning may demonstrate unsuspected metastases and likewise laparoscopy. Diagnostic cholangiography can be performed more easily by MR techniques than by endoscopy, but ERCP is still valuable for preoperative biliary decompression in appropriate patients. The role of angiography has declined. Percutaneous biopsy and peritoneal cytology are not usually required in patients with an apparently resectable tumour. The prognostic value of tumour marker levels and bone marrow biopsy is yet to be established. Preoperative chemotherapy or chemoradiation may have a role in down-staging an irresectable tumour sufficiently to render it resectable. Selective use of diagnostic laparoscopy staging is potentially helpful in determination of resectability. Laparotomy remains the definitive method for determining the resectability of pancreatic cancer, with or without portal vein resection, and should be undertaken in suitable patients without clear-cut evidence of irresectability.