Metabolic and morphological measurements of subcutaneous and visceral fat and their relationship with disease stage and overall survival in newly diagnosed pancreatic adenocarcinoma : Metabolic and morphological fat measurements in pancreatic adenocarcinoma.

ABSTRACT

PURPOSE: The relationship between tumor metabolism and stage, subcutaneous and visceral fat thickness, and their glucose metabolism and overall survival in patients recently diagnosed with pancreatic carcinoma was assessed. METHODS: Thirty-eight consecutive patients were studied. Subcutaneous fat thickness (SFT), visceral fat thickness (VFT), and their corresponding FDG SUVmean, as well as SUVmean and SUVmax values of the primary tumor (PT) were derived from FDG-PET CT imaging. Results obtained as well as clinical variables obtained, including gender and BMI, were related to patient outcome. Median follow-up was 382 days (range 36-917 days). RESULTS: Median age was 66 years (13 women). Mean BMI was 24.6 (SD 4.5). Lymph node (LN) involvement was diagnosed in 17 patients and 14 patients presented with distant metastases. Mean SUV max and SUVmean values of the PT were 9.0 (SD 5.9) and 4.2 (SD 2.1). Mean values of SFT and VFT were, respectively, 11.9 mm (range 1-31.7 mm) and 11.5 mm (range 0-49.8 mm). The corresponding SUVmean values were 0.4 (range 0-1.0) and 0.6 (range 0.0-1.6). SUVmean values of SFT proved significantly lower in LNpositive versus LNnegative patients (p = 0.021), in patients with and without metastatic disease (p = 0.017) and in stage III+IV patients versus stage I+II patients (p = 0.03). An inverse logarithmic relationship was found between SUVmean values of subcutaneous fat and SUVmean values of the PT (p = 0.02). Only disease stage dichotomized according to stage I+IIA versus stage IIB+III+IV was predictive of overall survival (p = 0.05). CONCLUSION: Glucose metabolism of subcutaneous fat in de novo diagnosed pancreas carcinoma patients presenting with lymph node involvement and metastatic disease is significantly reduced and inversely correlated to the primary tumor metabolism. Of the various fat-related variables studied, none proved significantly related to outcome.