Factors Associated with Favourable Pathological Tumour Response after Neoadjuvant Chemotherapy in Patients with Pancreatic Ductal Adenocarcinoma

Introduction Pathological response of pancreatic ductal adenocarcinoma (PDAC) to neoadjuvant chemotherapy (NAT) has been associated with oncological outcomes. The aim of the study was to investigate factors associated with favourable tumour regression in patients undergoing pancreatic resection for PDAC. Methods Patients who received NAT before undergoing PDAC resection at two institutions were reviewed. Tumour regression grading (TRG) was scored according to the College of American Pathologists (CAP) system. Interactions between chemotherapy, tumour and surgical factors with TRG were explored. Results 54 patients were identified, with 12 (22%) displaying a favourable response to NAT. The type of chemotherapy agent received, the number of cycles or a dose reduction during NAT course was not significantly different between the groups. The time from diagnosis to chemotherapy and time from end of chemotherapy to surgery were also similar between the groups. A favourable TRG was associated with greater disease-free survival median 33.2 months vs. 10.3 months; p=0.0) but not overall survival(median 43.8 months vs. 32.3 months; p=0.200), which may be due to small sample size. Conclusions Chemotherapy factors were not significantly related to a favourable response to NAT. Future studies should seek to identify modifiable factors associated with a favourable TRG.