Radiation Therapy Improves Survival Outcome in Pancreatic Adenocarcinoma: Comparison of a 15-Year Institutional Experience at the University of Nebraska Medical Center with SEER Data

Objectives. We examined the role of radiation therapy (RT) in pancreatic adenocarcinoma (PA) treatment through a 15-year retrospective analysis of patients treated at University of Nebraska Medical Center (UNMC) as well as those from the SEER database. Methods. A total of 561 patients diagnosed with PA at UNMC between 1995 and 2011 and 60,587 patients diagnosed between 1995 and 2009 from the SEER were included. Examined prognostic factors for overall survival (OS) were age, gender, race, stage, year of diagnosis, and treatment with surgery, chemotherapy (CT), or RT. Time to death was plotted by Kaplan-Meier method. A Cox proportional hazards model was used to evaluate prognostic factors for OS. Results. The median OS was 7.3 and 5 months for patients from UNMC and the SEER database, respectively. A Cox model of patients from UNMC showed that RT was associated with improved OS (HR 0.77, ) after adjusting for factors including age, race, gender, stage, year of diagnosis, having surgery, or having CT. Cox analysis of patients from the SEER showed similar results (HR 0.65, ). Conclusions. RT confers an independent survival advantage in patients being treated for PA which is apparent both at UNMC and through SEER data. 1. Introduction Pancreatic adenocarcinoma (PA) is currently the most lethal common cancer worldwide, with a 5-year survival rate of a dismal 6% [1]. It remains the 4th leading cause of cancer death in the United States and its incidence has been slowly increasing over the decades to its current lifetime risk of approximately 1 in 71. Further, the prospects for a curative treatment have not been promising. Studies regarding the best therapy for patient with PA have shown conflicting results. As such, there is much controversy regarding optimal treatment regimens for each PA stage [2]. No current consensus exists regarding the use of neoadjuvant or adjuvant therapies or what such therapies should consist of in resectable disease, nor is there widespread agreement on optimal regimen of treatment in borderline resectable or locally advanced unresectable PA. Even more controversial, however, is the role of each treatment modality in each of the proposed therapeutic schemas. While the ultimate goal of PA therapy remains R0 resection, the optimality of the use of chemotherapy (CT), radiation therapy (RT), and chemoradiotherapy (CRT) as well as the timing of their utilization(s) is unknown. Of these, the most controversial aspect of PA treatment is the incorporation of RT or CRT at all [3]. Though RT is limited by its localized nature, especially in a