The Oncological Stress Test of Neoadjuvant Therapy: A Systematic Review in Outcomes of Neoadjuvant Therapy Compared to Upfront Resection Approach for Borderline Resectable Pancreatic Adenocarcinoma.

Pancreatic adenocarcinoma, increasingly diagnosed in the United States, has a disheartening initial resection rate of 15%. Neoadjuvant therapy, particularly FOLFIRINOX and gemcitabine-based regimens, is gaining favor for its potential to improve resectability rates and achieving microscopically negative margins (R0) in borderline resectable cases, marked by intricate arterial or venous involvement. Despite surgery being the sole curative approach, actual benefit of neoadjuvant therapy remains debatable. This study scrutinizes current literature on oncological outcomes post-resection of borderline resectable pancreatic cancer. A MEDLINE/PubMed search was conducted to systematically compare oncological outcomes of patients treated with either neoadjuvant therapy with intent of curative resection or an "upfront resection" approach. A total of 1293 studies were initially screened and 30 were included (n = 1714) in this analysis. All studies included data on outcomes of patients with borderline resectable pancreatic adenocarcinoma being treated with neoadjuvant therapy (n = 1387) or a resection-first approach (n = 356). Patients treated with neoadjuvant therapy underwent resection 52% of the time, achieving negative margins of 43% (n = 601). Approximately 77% of patients who received an upfront resection underwent a successful resection, with 39% achieving negative margins. Neoadjuvant therapy remains marginally efficacious in treatment of borderline resectable pancreatic adenocarcinoma, as patients undergo an operation and successful resection less often when treated with neoadjuvant therapy. Rates of curative resection are comparable, despite neoadjuvant therapy being a primary recommendation in borderline resectable cases and employed more often than upfront resection. Upfront resection may offer improved resection rates by intention-to-treat, which can provide more patients with paths to curative resection.