Comparison of the sendai and fukuoka consensus guidelines for the management of mucinous cystic lesions of the pancreas: are we making progress?

Cystic lesions of the pancreas (CLP) are increasingly being found incidentally, due largely to the frequency of three-dimensional (3D) abdominal imaging. The algorithm of resecting all solid pancreatic lesions does not apply to all cystic pancreatic lesions; observation is undoubtedly the most appropriate management for most pancreatic cysts. The series of 317 patients with CLPs reported by Goh et al. in this issue of Annals of Surgical Oncology addresses the core of these diagnostic dilemmas—which criteria should be applied to CLPs as clinicians decide which lesions warrant pancreatic resection? The authors should be recognized for their large study size, systematic review, and thorough application of two widely utilized classification systems: the 2006 Sendai Consensus Guidelines (SCG) and the revised Sendai criteria, also referred to as the Fukuoka Consensus Guidelines (FCG). This comparison is critical as our understanding of CLPs evolves. The 2006 SCG were the first multidisciplinary, standardized recommendations for clinicians counseling patients on the optimal management of their pancreatic cysts, specifically designed to risk-stratify patients with intraductal papillary mucinous neoplasms (IPMNs) or mucinous cystic neoplasms (MCN). Based on these guidelines, all main duct and mixed-type IPMNs, and all MCN should be resected for a patient of appropriate operative risk. However, the Sendai criteria most prominently clarified our understanding of which side-branch (SB) IPMNs required operative intervention. An SB-IPMN associated with high-risk features such as the presence of an intracystic mural nodule, associated main duct dilation of 10 mm, and size greater than 3 cm were considered to be of sufficient risk to warrant resection. For SB-IPMNs that did not meet these criteria, observation at specific intervals dictated by cyst size was considered safe. Following the publication of these guidelines, the risk of dysplasia and malignancy developing in cysts less than 3 cm in size began to be more closely evaluated. In a report from the Moffitt Cancer Center, 105 patients with CLPs underwent definitive surgical therapy. The authors found that in cysts\3 cm in size, the rate of malignancy on final pathology was 34 %, and concluded that this rate of invasion was prohibitively high to recommend surveillance. At the same time, a study by Fritz et al. concurred with the Moffitt group. In this investigation, from a population of 123 resected SBIPMNs, 69 were declared ‘Sendai negative’ (fulfilling none of the high-risk features outlined in the 2006 guidelines), and 17 (25 %) were found to have either high-grade dysplasia (HGD) or invasive ductal carcinoma within the specimen. The authors concluded that a size cutoff of 3 cm was too liberal for safe observation in patients with SB-IPMNs. However, these studies have significant limitations. In neither of these reports are other characteristics of the IPMNs comprehensively stated—how many contained mural nodules, were cytologically positive for malignancy prior to resection, or grew over time. Any one of these features of a SB-IPMN increase the risk of that lesion harboring malignancy, and without clearly understanding the true numerators and denominators in these investigations, accurately estimating the risk of malignancy is not possible—we do not know how many lesions were truly ‘Sendai negative’. In particular, the study from Moffit was unique in that the authors utilized endoscopic ultrasound (EUS) to evaluate the patients in their series, which implies that only cysts with high-risk features were being resected. Society of Surgical Oncology 2014