Neoadjuvant radiation followed by resection versus upfront resection for locally advanced pancreatic cancer patients: a propensity score matched analysis

BACKGROUND AND AIM: To compare cancer-specific survival (CSS) between patients who received neoadjuvant radiation followed by resection (NRR) and those who received upfront resection (UR) for locally advanced pancreatic cancer (LAPC). METHODS: A total of 772 LAPC patients who underwent curative-intent surgical resection with or without neoadjuvant radiation from 2004 to 2013 were identified from the Surveillance, Epidemiology, and End Result (SEER) database. Propensity score matching (PSM) was conducted to eliminate possible bias. Kaplan-Meier method was used to analyze long-term outcome. Independent risk factors of CSS were predicted by Cox proportional hazards model. Subgroup analyses were done according to 5 variables. RESULTS: The propensity score model matched 196 patients from the whole cohort. Neoadjuvant radiation was an independent predictor of CSS no matter before or after PSM. After PSM, the 1-, 3-, 5-year CSS rates of NRR group were 82.7%, 39.2% and 17.1%, while 64.3%, 19.9% and 12.4% for UR group. The median CSS for NRR group was 25 months, while 17 months for UR group. In subgroup analyses, CSS rates or median CSS of NRR group were still superior to those of UR group in married, unmarried, pancreatic adenocarcinoma, G1+G2, G3+G4, N0 stage, N1 stage and M0 stage subgroups, but no differences were found in other histological types and M1 stage subgroups. Other predictors of CSS included histological type, tumor grade and marital status. CONCLUSIONS: Neoadjuvant radiation followed by resection has a significant survival benefit compared with upfront resection in LAPC patients. Therapeutic strategy for LAPC patients should be further explored.