Neoadjuvant Treatment vs Upfront Surgery for Left-Sided Pancreatic Cancer

Pancreatic cancer is one of the most treatment resistant malignancies, often diagnosed at a late stage and associated with poor survival. The 5-year overall survival rate remains around 10%. Prognosis is affected by multiple factors including tumor stage, biology, treatment response, and anatomical location. Distal (left-sided) pancreatic cancer, originating from the body or tail of the pancreas, accounts for approximately 20-25% of all pancreatic cancers and has been associated with worse survival than pancreatic head cancer, even when adjusted for stage. This may be due to histological, molecular, and embryological differences, and varied systemic therapy responses. Neoadjuvant chemotherapy has become increasingly important in managing pancreatic cancer. It may improve outcomes by reducing tumor size, allowing for more complete (R0) resections, treating micrometastatic disease early, and identifying patients unlikely to benefit from surgery. While neoadjuvant therapy is recommended for borderline resectable and locally advanced tumors, randomized trials have not shown benefit for patients with upfront resectable pancreatic head cancer. Importantly, no randomized controlled trials have investigated the benefit of neoadjuvant treatment specifically in patients with upfront resectable left-sided pancreatic cancer, despite its distinct biology and worse prognosis. Retrospective data suggest neoadjuvant therapy may improve survival in left-sided tumors. A recent multicenter study reported significantly longer overall survival in patients treated with neoadjuvant therapy compared to upfront surgery alone. However, prospective randomized data are lacking. This multicenter randomized trial aims to assess whether patients with resectable left-sided pancreatic cancer benefit from neoadjuvant chemotherapy compared to upfront surgery. The study will reflect real-world clinical practice by allowing both commonly used regimens-FOLFIRINOX and Gemcitaine-Nab-paclitaxel -as neoadjuvant options. Previous studies have shown these regimens to be similarly effective, and switching between them due to toxicity or progression is feasible and does not seem to impair surgical outcomes or survival. This study aims to evaluate the benefits of neoadjuvant chemotherapy before surgery in a prospective multicenter randomized setting for resectable left-sided pancreatic cancer patients.

This is a multicenter, open-label, randomized phase III trial evaluating whether neoadjuvant chemotherapy improves overall survival in patients with resectable left-sided (body/tail) pancreatic cancer compared to the current standard of upfront surgery followed by adjuvant chemotherapy. Eligible patients have histologically confirmed pancreatic adenocarcinoma located in the body or tail of the pancreas, ECOG/WHO performance status 0-2, and radiologically resectable disease according to NCCN criteria. Patients are randomized 1:1 to receive either: 1. neoadjuvant chemotherapy, followed by surgery and adjuvant therapy, or 2. upfront surgery followed by adjuvant chemotherapy. Randomization uses a minimization method with stratification by performance status, CA19-9 level, treatment center, and chemotherapy regimen. Surgery is scheduled within 4-6 weeks of randomization (control arm) or after the last neoadjuvant cycle (intervention arm). Left pancreatectomy (open or minimally invasive) with standard lymphadenectomy and splenectomy is performed with complications reported using Dindo/Clavien classification and ISGPS criteria. Radical antegrade posterior pancreatosplenectomy may be performed when needed to ensure clear margins. Tumor response to neoadjuvant therapy will be evaluated by standardized histopathological grading. Patients are followed with laboratory tests and CT imaging at the completion of adjuvant therapy and every six months thereafter until disease recurrence or up to five years after surgery. Quality of life is assessed at baseline, pre-surgery (in the neoadjuvant arm), 4 weeks post-op, and during follow-up using the EORTC QLQ-C30 and PAN26 instruments. Patients are followed for recurrence and survival every 6 months for up to 5 years. Safety is monitored per CTCAE v5.0, with SAEs and SUSARs reported per regulatory guidelines. An independent DSMB will review safety data. Blood and tumor samples will be stored for future translational research. The primary endpoint is overall survival. A total of 381 patients will be enrolled over 36 months. The trial is powered to detect a hazard ratio of 0.70 with 80% power and a 5% significance level, requiring 247 events (deaths). Analysis will follow the intention-to-treat principle using Kaplan-Meier, log-rank test, and Cox regression. Pre-specified subgroup analyses will assess factors such as age, performance status, CA19-9, and tumor characteristics.