Neoadjuvant management of locally advanced pancreatic ductal adenocarcinoma − Heading towards a promising change in treatment paradigm

Abstract

Traditional chemotherapy-based adjuvant therapies for locally advanced pancreatic ductal adenocarcinoma (PDAC) have been associated with poor clinical outcomes driven partly by its complex anatomy and molecular heterogeneity. Treatment for PDAC is challenged by presence of a dense tumour microenvironment involving an interplay of multiple tumoural and stromal components which promote metastatic oncogenic behaviour. PDAC also involves aberrations in multiple signalling pathways with paucity of treatment options against the most common mutations including KRAS, TP53, CDKN2A and SMAD4. However, recent discovery of new mechanisms implicated in pancreatic carcinogenesis have led to identification of promising mechanistic therapeutic targets such as NET1 and ULK1. Early evidence also suggests the utility of targeting multiple DNA repair processes, modulators of DNA replication and major DNA damage response regulators. We explore the clinical rationale behind a neoadjuvant therapeutic strategy and emerging predictors of survival benefit associated with this approach. We also discuss challenges and opportunities originating from recent clinical trials evaluating neoadjuvant treatments composed of various combinations of radiotherapy, chemotherapy and immunotherapeutic regimens that have aimed to address some of these biological challenges. Selective treatment of patients harbouring specific genomic aberrations with targeted agents and immunotherapy can translate into optimum survival outcomes in PDAC. We also share perspectives on emerging prospective clinical evidence regarding stromal modifying agents, such as Tumour Growth Factor-Beta and Connective Tissue Growth Factor inhibitors along with novel vaccination-based approaches in improving PDAC outcomes.