Interferon-based Adjuvant Chemoradiation for Resected Pancreatic Head Cancer: Long-term Follow-up of the Virginia Mason Protocol.

Abstract

To report the long-term impact of adjuvant interferon-based chemoradiation therapy (IFN-CRT) after pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDAC). In 2003, we reported an actuarial 5-year overall survival (OS) of 55% (22 months median follow-up) using adjuvant IFN-CRT after PD. As the original cohort is now 10 years distant from PD, we sought to examine their actual survival, describe patterns of recurrence, and determine prognostic factors. From 1995 to 2002, 43 patients underwent PD for PDAC and received adjuvant IFN-CRT consisting of external-beam irradiation, continuous 5-fluorouracil infusion, weekly intravenous bolus cisplatin, and subcutaneous interferon-α. Survival was calculated by the method of Kaplan and Meier, and prognostic factors were compared using a log-rank test and a Cox proportional hazards model. With all patients at least 10 years from PD, the 5-year actual survival was 42% and 10-year actual survival was 28% with median OS of 42 months (95% confidence interval: 22-110 months). Nine patients survived beyond 10 years with 7 currently alive without evidence of disease. Initial recurrence included 4 local, 17 distant, and 4 combined sites at a median of 25 months. IFN-CRT was interrupted in 70% of patients because of grade 3 or 4 toxicity, whereas 42% of patients required hospitalization. Adverse prognostic factors included lymph node ratio of 50% or more, Eastern Cooperative Oncology Group performance status of 1 or higher, and IFN-CRT treatment interruption. Adjuvant IFN-CRT after PD can provide long-term survival in resected PDAC. Further studies should focus on patient and tumor factors to maximize benefit and minimize toxicity.