Neoadjuvant Chemotherapy Enhances Local Postoperative Histopathological Tumour Stage in Borderline Resectable Pancreatic Cancer - A Matched-Pair Analysis.

Abstract

Neoadjuvant chemotherapy (NAC) is established in the treatment of ductal pancreatic adenocarcinoma for downsizing borderline-resectable pancreatic cancer (BRPC) and may affect nodal positivity and rates of R0 resection. This study aimed to identify the impact of NAC on postoperative histopathological parameters with a prognostic relevance. A one-to-three matched-pair analysis, including an overall total of 132 patients (25% treated with NAC and subsequent resection and 75% undergoing upfront surgery) was performed. Influence of NAC on nodal positivity, lymphatic, vascular and perineural invasion, as well as resection stage and grading, was examined. Furthermore, perioperative complications, in-hospital stay, re-admission rates, mortality, as well as preoperative body mass index and American Association of Anesthesiologist classification scores, were evaluated. Patients treated with NAC significantly less frequently had lymphatic tissue invasion (lymph node invasion: 51.5% vs. 72.7%; p=0.032, and lymphatic vessel invasion 9.4% vs. 55.3%; p=0.0004), whereas vascular and perineural invasion, as well as grading and resection state were not significantly different. Carbohydrate antigen 19-9 regression in correlation with nodal positivity also did not differ, and both groups showed comparable perioperative complication rates. Occurrence and severity of postoperative pancreatic fistula (18.2% vs. 24.3%; p=0.034) were significantly lower in patients who had undergone NAC. NAC significantly affects postoperative histopathological tumour stage in BRPC and appears to be a safe treatment option without increased perioperative complications, re-admission, in-hospital stay, or mortality. Further studies are mandatory to underline the suitability of NAC for ductal pancreatic adenocarcinoma subgroups in order to guide clinicians in their daily decision-making comprehensively.