Chemoradiotherapy is associated with improved survival for resected pancreatic adenosquamous carcinoma: a retrospective cohort study from the SEER database

Background: The prognosis of pancreatic adenosquamous carcinoma (PASC) after surgery is pm-. The purpose of this study was to clarify the prognostic factors of PASC and evaluate the efficacy of combination chemoradiotherapy. Methods: The patients' data retrieved from the Surveillance, Epidemiology, and End Results database (SEER) between 2004 and 2015 were stratified and analyzed in this study. The univariate and multivariate analysis were used for overall survival (OS) and cancer-specific survival (CSS). Results: T staging, M staging, chemotherapy and radiotherapy is the independent prognostic indicator after PASC resection for both OS and CSS. In the total cohort, 44 patients had both chemo and radiotherapy, with median OS 23 months and CSS 29 months, which was significantly better than neither chemo nor radiotherapy group (68 patients, median OS 8 months and CSS 11 months), and either chemotherapy or radiotherapy group (91 patients, median OS 13 months and CSS 15 months). The survival benefit of chemoradiotherapy was validated in the specific group (n=159) who had only primary PASC. PASC patients receiving chemoradiotherapy had longer OS and CSS than those with neither chemo nor radiotherapy in TNM stage I, II and IV subgroups. Conclusions: The chemoradiotherapy revealed its prognostic superiority in PASC treatment.