Comment On: Prospective Phase II Trials Validate the Effect of Neoadjuvant Chemotherapy on Pattern of Recurrence in Pancreatic Adenocarcinoma.

Abstract

We read with great interest the article by Dr. Chawla et al.1 They investigated the pattern of recurrence from a retrospective cohort of patients treated with neoadjuvant chemotherapy (NAC) followed by chemoradiation and then surgery or surgery first followed by adjuvant chemotherapy and 2 prospective cohorts of patients derived from 2 phase II clinical trials assessing patients treated with NAC in borderline-resectable and locally advanced pancreatic adenocarcinoma (PDAC). They found that the site of recurrence in PDAC is mostly distant metastasis (DM) rather than locoregional, regardless of the use of NAC and margin status. After reading their article, we have some questions that we hope to communicate with the authors. First, the authors consider that the surgical margin distance less than 1 mm of the resection is R1 resection, which can be agreed upon by most surgeons in the resectable or borderline-resectable cohort. However, in the locally advanced cohort, for PDCA with vascular invasion, how did the authors determine the status of the surgical margin because the tumor was removed along the vessels? In theory, for PDCA with vascular invasion, the surgical margin distance is always less than 1 mm. Then, according to the authors’ definition of surgical margin, PDCA with vascular invasion would have no way to achieve an R0 resection. Second, in the locally advanced cohort, the DM rate was only 67%. Patients in the locally advanced cohort had the highest tumor stage but the lowest DM rate compared to other cohorts. Different from the treatment of other cohorts (surgery + adjuvant therapy), losartan is added to the treatment in the locally advanced cohort. Is the decrease in DM associated with the use of losartan? To observe recurrence patterns consistent with the rest of the cohort, we think that treatment in the locally advanced cohort should be substantially consistent with the rest of the cohort. We raise these questions not to challenge Chawla et al.’s1 research but to have a friendly academic exchange with them. And, we acknowledge Chawla et al.1 for their contribution to the discovery of recurrence patterns in PDCA. Meanwhile, we are also very grateful to Annals of Surgery Open for giving us a platform to communicate.