Borderline resectable pancreatic cancer: an evolving concept
Authors: N. Petrucciani, T. Debs, G. Nigri, F. D’Angelo, J. Gugenheim, G. Ramacciato
Journal: Annals of Oncology (2017)

We read with interest the article entitled ‘Borderline resectable pancreatic cancer: conceptual evolution and current approach to image-based classification’ published in the Annals of Oncology, in April 2017, by Gilbert et al. [1.Gilbert J.W. Wolpin B. Clancy T. et al.Borderline resectable pancreatic cancer: conceptual evolution and current approach to image-based classification.Ann Oncol. 2017; 28: 2067-2076Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar]. The review extensively discusses the major controversies concerning borderline resectable pancreatic cancer (BRPC): lack of universally agreed definition, variance in institution-by-institution practice, and lack of solid evidence concerning management of these patients. We congratulate the authors for the excellent work and would like to solicit authors’ expert opinion about some points. As you stated, computed tomography (CT) with pancreatic protocol represents the mainstay for preoperative staging of pancreatic cancer, eventually complemented by magnetic resonance (MRI) and positron emission tomography (PET). In the subsetting of BRPC, Glazer et al. [2.Glazer E.S. Rashid O.M. Klapman J.B. et al.Endoscopic ultrasonography complements computed tomography in predicting portal or superior mesenteric vein resection in patients with borderline resectable pancreatic carcinoma.Pancreatology. 2017; 17: 130-134Crossref PubMed Scopus (13) Google Scholar] suggested that the addition of echoendoscopy might complement the results of CT scans, predicting the need for vessel resection and identifying borderline resectable cases ‘missed’ by CT. In their study, echoendoscopy predicted the need for venous resection in 88% of patients versus 67% of CT scans. What is your opinion about echoendoscopy in the staging of BRPC? Imaging after neoadjuvant therapy is difficult to interpret because residual tumor, scarring from tumor regression, inflammatory changes from neoadjuvant therapy and tumor fibrosis cannot be differentiated. Therefore, surgical exploration is recommended in the absence of the development of tumor metastases or tumor progression. Even if PET is not routinely recommended during pre-treatment staging, we would like to point out its potential role in evaluating the response to neoadjuvant therapy. Recently Akita et al. [3.Akita H. Takahashi H. Ohigashi H. et al.FDG-PET predicts treatment efficacy and surgical outcome of pre-operative chemoradiation therapy for resectable and borderline resectable pancreatic cancer.Eur J Surg Oncol. 2017; Abstract Full Text Full Text PDF Scopus (32) Google Scholar] have shown that the SUV-max after neoadjuvant therapy was lower in histological responders than in non-responders. The regression index, defined as the percentage of SUV decline, was related to histological response, and to overall patients survival. These results suggest that PET, and mainly comparison of pre-neoadjuvant with post-neoadjuvant SUV, may be useful as an imaging modality to assess tumor response. Definition of BRPC is nowadays based on anatomic/radiological criteria. It is known that anatomic criteria have a prognostic impact. However, other criteria not detectable with imaging modalities are related to prognosis, such as histological venous invasion [4.Wang F. Gill A.J. Neale M. et al.Adverse tumor biology associated with mesenterico-portal vein resection influences survival in patients with pancreatic ductal adenocarcinoma.Ann Surg Oncol. 2014; 21: 1937-1947Crossref PubMed Scopus (33) Google Scholar]. Furthermore, novel biologic and molecular factors, which may be analyzed on the preoperative biopsy specimen, are emerging and are related to the prognosis [5.Pishvaian M.J. Brody JR. Therapeutic implications of molecular subtyping for pancreatic cancer.Oncology (Williston Park). 2017; 31: 159-168PubMed Google Scholar]. Do you feel that in the future a biological-anatomical definition of BRPC may replace the current definition? We agree that a key concept is that resectability exists along a continuous spectrum. Even after all effort to define it, BRPC remains an ‘imprecise continuum between radiologically and technically resectable and unresectable disease’ [6.Katz M.H. Pisters P.W. Evans D.B. et al.Borderline resectable pancreatic cancer: the importance of this emerging stage of disease.J Am Coll Surg. 2008; 206: 833-846Abstract Full Text Full Text PDF PubMed Scopus (644) Google Scholar]. Definition terms are often ambiguous, and there is no universal consensus. Furthermore, the definition of BRPC has already evolved and may further evolve with better understanding of tumor biology in the future. Radiological criteria are fundamental and should ideally be universally agreed and very detailed, in order to provide the correct disease classification and treatment to these patients. Efforts are needed to reach evidence based staging criteria and treatment recommendations. We congratulate the authors for clearly elucidating this topic. None declared.