Laparoscopic Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma: Time for a Randomized Controlled Trial? Results of an All-inclusive National Observational Study
With great interest, we read the study by Sulpice et al1 on outcomes after laparoscopic and open distal pancreatectomy (DP) for pancreatic ductal adenocarcinoma (PDAC) in 199 centers in France (2007–2012). We congratulate the authors on reporting a national experience on DP for PDAC with comparison of the laparoscopic and open approaches. The conclusions of this work demonstrate reduced pleuropulmonary morbidity, reduced blood transfusion, shortened median length of stay, and an increased median postoperative survival in favor of laparoscopic DP.
In assessing the study design and results, we have some questions. The authors report on over 2700 DPs for PDAC during a 6-year period in France alone, which would account for approximately 450 DPs for PDAC annually. Data from another registry study, from the United States,2 showed that 385 DPs were performed for PDAC annually, so it seems that there are more DPs for PDAC performed in France as compared with the United States, despite having one fifth the population. Do the authors have an explanation for this discrepancy?
In their article, the authors describe that detailed pathology data was lacking. Could this factor have an impact on the results of this study? Could the study population have been contaminated with diagnoses other than PDAC—that is, neuroendocrine tumors, cystadenocarcinomas, and more likely adenocarcinoma arising from intraductal papillary mucinous neoplasms, all of which portend better survival than true PDACs? Bias caused by heterogeneity in pancreatic pathology could also clarify the exceptional high median postoperative survival rate of 38 months in this study, which does not correspond to large recent US and Dutch multicenter studies on this topic in which a median survival of 16 to 17 months was seen after histologic review.3–6 Left-sided PDAC is often diagnosed at an advanced stage because of the lack of specific symptoms and therefore we do not expect survival after DP to be better than for pancreatoduodenectomy for the same indication. It is therefore unclear how to compare the 38 months survival in this series to the 20 months median survival after pancreatoduodenectomy for PDAC, which was recently reported in a French multicenter study.6 A heterogenetic case mix or high numbers of missed out-of-hospital-deaths in the paper by Sulpice et al1 would explain this obvious difference.
However, we strongly agree with the authors that the next step should be a randomized controlled trial in high-quality centers with rigorous endpoint evaluation. Currently, the DIPLOMA trial study group in Europe has gathered support around Europe, including France, for a randomized controlled trial in this patient category. When the ongoing pan-European cohort study will confirm the feasibility of the DIPLOMA trial, this will provide us with the platform needed to give concluding evidence on the merits of laparoscopic distal pancreatectomy in PDAC.