Neoadjuvant external beam radiation is associated with No benefit in overall survival for early stage pancreatic cancer

Abstract

Objective: Neoadjuvant protocols for early stage pancreatic adenocarcinoma (PDAC) frequently involve external beam radiation used in combination with systemic chemotherapy. The benefit of radiation in these protocols has not been determined.

Methods: We examined patients with stage I and II PDAC within the National Cancer Data Base between 2006 and 2012. Propensity score matching was used to compare patients receiving neoadjuvant chemotherapy including radiation (NCRT) to those receiving neoadjuvant chemotherapy without radiation (NCT) prior to pancreaticoduodenectomy.

Results: Prior to matching, NCRT patients had higher rates of T3 tumors (P = 0.046) and vascular abutment (P < 0.001). Propensity score matching (1:1) yielded 397 patients per group. Patients treated with NCRT were more likely to have node negative resections (P < 0.001) but had increased rates of 90-day mortality (P = 0.015) and demonstrated a trend towards shorter overall survival (P = 0.0502) than those receiving NCT.

Conclusion: In early stage PDAC, the addition of radiation to NCT is often utilized with more advanced disease and is associated with higher perioperative mortality and no long-term overall survival benefit.

Keywords: Neoadjuvant therapy; Overall survival; Pancreatic cancer; Pancreatic ductal adenocarcinoma; Pancreaticoduodenectomy; Radiation therapy.