Low 18f-fluorodeoxyglucose uptake on positron emission tomography as a prognostic factor for stage I and II pancreatic cancer.

Abstract

159 Background: Metabolic activity as defined by the uptake of 18F-fluorodeoxyglucose (FDG) on Positron Emission Tomography (PET) has proven beneficial as a prognostic marker for multiple malignancies; however, no study has examined the prognostic value of PET in stage I and II pancreatic cancer. We examined the value of PET FDG uptake in early pancreatic cancer. Methods: Using a comprehensive pancreatic adenocarcinoma database, we identified patients with early stage pancreatic cancer (I-II) who underwent pancreatectomy for cancer and had PET scan performed as part of their preoperative evaluation from 2004 to 2010. Patients were divided by the median primary tumor standard uptake value (SUVmax) into two groups: high and low FDG uptake. The primary outcomes were overall survival (OS) and disease free survival (DFS). Kaplan-Meier estimate was used for survival analysis. Pathologic data were compared using Fisher's exact and chi-square. Results: We identified 105 patients with resected stage I and II pancreatic cancer who had PET scans as part of their preoperative evaluation. 51 patients had low FDG uptake while 54 patients had high FDG uptake. The median age at diagnosis was 69 (24-89) years, 57% of the patients were male. 84 (81%) patients had PET avid tumors, while 20 (19%) patients did not. The median SUVmax was 5.1. High FDG uptake correlated with pathologic stage (p=0.012). Median follow-up was 12.3 (0-56) months. Patients with low FDG uptake had a significantly better median OS than patients with high FDG uptake (27 vs. 16 months; p=0.036). Recurrence occurred in 64 (60%) patients. Patients with low FDG uptake had significantly longer median DFS than patients with high FDG uptake (14 vs. 12 months; p=0.049). Conclusions: Low 18F-fluorodeoxyglucose uptake in PET scans for stage I and II pancreatic cancer correlates with improved overall survival and disease free survival. This observation supports the concept that glucose metabolic pathways are important in pancreatic cancer biology, and that PET scan activity can be used as a prognostic biomarker after pancreatectomy for pancreatic cancer.