Can statistically determined prognostic factors predict the long-term survival of patients with pancreatic ductal adenocarcinoma following surgical resection?: Clinicopathological analysis of 82 long-term survivors.

OBJECTIVE: The objective of this study were to analyze and describe the clinicopathological characteristics of long-term pancreatic ductal adenocarcinoma survivors and to determine if statistically identified prognostic factors can be used to predict the actual survival.
METHODS: Between January 2000 and December 2007, 537 patients with resectable pancreatic ductal adenocarcinoma underwent surgical resection at a single institute. Medical records were retrospectively reviewed, and 9 patients were excluded. Of the remaining 528, patients who survived for more than 5 years were classified as long-term survivors.
RESULTS: The actual 5-year survival rate of all 528 included patients was 15.5% (82 patients; median follow-up period, 82.7 months). Fifty-eight patients (70.7%) were diagnosed with cancers located in the head of pancreas, and the median size was 2.5 cm (range, 0.8-12.0 cm). Three patients had focal involvement noted on the resected surfaces. Poorly differentiated carcinoma (9.8%), lymph node metastasis (32.9%), lymphovascular invasion (25.6%), and perineural invasion (48.8%) were detected. Fifty-five of the 82 long-term survivors whose clinicopathological characteristics included several dismal predictors survived for more than 5 years without recurrence.
CONCLUSIONS: The long-term survivors identified in this study did not meet the appropriate prognostic criteria. Therefore, there are limitations in the use of statistically determined prognostic factors for estimating in the long term.