Neoadjuvant Treatment for Pancreatic Adenocarcinoma: A False Promise or an Opportunity to Improve Outcome?

Abstract

Pancreatic ductal adenocarcinoma (PDAC) has an aggressive tumor biology and is associated with poor survival outcomes. Most patients present with metastatic or locally advanced disease. In the 10-20% of patients with upfront resectable disease, surgery offers the only chance of cure, with the addition of adjuvant chemotherapy representing an established standard of care for improving outcomes. Despite resection followed by adjuvant chemotherapy, at best, 3-year survival reaches 63.4%. Post-operative complications and poor performance mean that around 50% of the patients do not commence adjuvant chemotherapy, and a significant proportion do not complete the intended treatment course. These factors, along with the advantages of early treatment of micrometastatic disease, the ability to downstage tumors, and the increase in R0 resection rates, have increased interest in neo-adjuvant treatment strategies. Here we review biomarkers for early diagnosis of PDAC and patient selection for a neo-adjuvant approach. We also review the current evidence for different chemotherapy regimens in this setting, as well as the role of chemoradiotherapy and immunotherapy, and we discuss ongoing trials.

Keywords: biomarkers; immunotherapy; neo-adjuvant chemotherapy; pancreatic ductal adenocarcinoma; radiotherapy; resectability.

Figure 1

Regimens for neoadjuvant chemoradiotherapy or chemotherapy in patients with pancreatic adenocarcinoma. Legend. CAPE: capecitabine; CI: continuous infusion; CRT: chemoradiotherapy; CT: chemotherapy: GEM: gemcitabine; h: hours; IGRT: image-guided radiotherapy; IMRT: intensity-modulated radiotherapy; IRI: irinotecan; LV: leucovorin; NAB-PAC: nab-paclitaxel; OXA: oxaliplatin; RT: radiotherapy; SBRT: stereotactic body radiation therapy; 5-FU: 5-fluorouracil. * 825 mg/m² in FOLFIRINOX → CAPE + RT trial, 830 mg/m² in ESPAC 5F trial.