Downstaging in pancreatic cancer: a matched analysis of patients resected following systemic treatment of initially locally unresectable disease.

BACKGROUND: Patients with locally unresectable pancreatic cancer (AJCC stage III) have a median survival of 10-14 months. The objective of this study was to evaluate outcome of initially unresectable patients who respond to multimodality therapy and undergo resection.
METHODS: Using a prospectively collected database, patients were identified who were initially unresectable because of vascular invasion and had sufficient response to nonoperative treatment to undergo resection. Overall survival (OS) was compared with a matched group of patients who were initially resectable. Case matching was performed using a previously validated pancreatic cancer nomogram.
RESULTS: A total of 36 patients with initial stage III disease were identified who underwent resection after treatment with either systemic therapy or chemoradiation. Initial unresectability was determined by operative exploration (n = 15, 42%) or by cross-sectional imaging (n = 21, 58%). Resection consisted of pancreaticoduodenectomy (n = 31, 86%), distal pancreatectomy (n = 4, 11%), and total pancreatectomy (n = 1, 3%). Pathology revealed T3 lesions in 26 patients (73%), node positivity in 6 patients (16%), and a negative margin in 30 patients (83%). The median OS in this series was 25 months from resection and 30 months since treatment initiation. There was no difference in OS from time of resection between the initial stage III patients and those who presented with resectable disease (P = .35).
CONCLUSIONS: In this study, patients who were able to undergo resection following treatment of initial stage III pancreatic cancer experienced survival similar to those who were initially resectable. Resection is indicated in this highly select group of patients.