Clinical implication of FDG-PET in advanced gastric cancer with signet ring cell histology

Background and Objectives: The purpose of this study was to investigate the role of the standardized uptake values (SUV), a semi-quantitative assessment of tumor FDG uptake, as a prognosticator for advanced signet ring cell carcinoma (SRC). Methods: We reviewed the files of 41 patients who underwent curative gastrectomy for advanced SRC and who had an FDG-PET at initial presentation between September 2003 and December 2007. Results: The median follow-up period was 30.9 months (range: 4.0-70.3). We found a correlation between the SUVmax and TNM stage. When the patients were divided into two groups (low vs. high SUVmax) based on a median SUVmax of 3.80, the high-SUVmax group showed more aggressive tumor behavior than did the low SUVmax group. In addition, the high SUVmax group showed more postoperative recurrence (P=0.028), shorter relapse-free survival (P=0.004), and lower 30-month cancer-specific survival rates (40.0%vs.69.3%,P=0.008).However, in multivariate analysis, SUVmax failed to be anindependent predictor of overall survival. Conclusions Although SUVmax of initial PET scan was not an independent predictor of patient outcomes after curative surgery, higher SUVmax is associated with more advanced stage and indicates more aggressive tumor biology in advanced SRC.