Neoadjuvant stereotactic body radiation therapy for nonmetastatic pancreatic adenocarcinoma

Background: Neoadjuvant therapy is a strategy for resectable and borderline resectable pancreatic cancer, but a consensus approach regarding optimal management is undetermined. Neoadjuvant options include chemotherapy with/without radiotherapy. Stereotactic body radiation therapy (SBRT) is a novel radiation technique that may provide benefit over conventionally fractionated radiation therapy (CFRT) in the neoadjuvant setting. The purpose of the present study is to determine neoadjuvant treatment with SBRT to other neoadjuvant treatment options for patients with resectable pancreatic cancer. Material and methods: The National Cancer Database was queried (2004–2015) for patients with nonmetastatic pancreatic adenocarcinoma receiving neoadjuvant therapy followed by pancreatectomy. Patients were categorized based on the type of neoadjuvant treatment administered. Statistics included temporal trend assessment by annual percent change (APC), predictors for SBRT by multivariable logistic regression, Kaplan–Meier overall survival (OS) analysis without and with propensity matching, and Cox proportional hazards modeling for univariable OS analysis. Results: Of 5828 patients, 332 (5.7%), 3234 (55.5%) and 2262 (38.8%) received neoadjuvant chemo-SBRT, chemotherapy, and chemo-CFRT, respectively. SBRT utilization increased from 0% in 2004 to 9.5% in 2015, with a greater APC after 2010 (p <.001). SBRT was more likely to be utilized in patients with T3–4 and node-positive disease (p <.05 for all). The chemo-SBRT cohort was associated with a higher OS rate before and after propensity matching (p <.05 for both). The rate of R0 resection was higher in radiotherapy groups than the chemotherapy cohort (p <.001). Conclusions: Utilization of neoadjuvant SBRT for pancreatic cancer is increasing. In the neoadjuvant setting, chemo-SBRT may improve R0 resection and OS over chemotherapy and chemo-CFRT, although confirmatory prospective studies are needed for confirmation.