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

ABSTRACT

OBJECTIVE: To report the long-term impact of adjuvant interferon-based chemoradiation therapy (IFN-CRT) after pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDAC). BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.