Impact of preoperative [18F]FDG PET/CT vs. contrast-enhanced CT in the staging and survival of patients with clinical stage I and II non-small cell lung cancer: a 10-year follow-up study

Abstract

Objectives: To elucidate the impact of [¹⁸F]FDG positron emission tomography/computed tomography (PET/CT) vs. CT workup on staging and prognostic evaluation of clinical stage (c) I-II NSCLC.

Methods: We retrospectively identified 659 cI-II NSCLC who underwent CT (267 patients) or preoperative CT followed by PET/CT (392 patients), followed by curative-intended complete resection in our hospital from January 2008 to December 2013. Differences were assessed between preoperative and postoperative stage. Five-year disease-free survival (DFS) and overall survival (OS) rates were calculated using the Kaplan-Meier approach and compared with log-rank test. Impact of preoperative PET/CT on survival was assessed by Cox regression analysis.

Results: The study included 659 patients [mean age, 59.5 years ± 10.8 (standard deviation); 379 men]. The PET/CT group was superior over CT group in DFS [12.6 vs. 6.9 years, HR 0.67 (95% CI 0.53-0.84), p < 0.001] and OS [13.9 vs. 10.5 years, HR 0.64 (95% CI 0.50-0.81), p < 0.001]. In CT group, more patients thought to have cN0 migrated to pN1/2 disease as compared with PET/CT group [26.4% (66/250) vs. 19.2% (67/349), p < 0.001], resulting in more stage cI cases being upstaged to pII-IV [24.7% (49/198) vs. 16.1% (47/292), p = 0.02], yet this was not found in cII NSCLC [27.5% (19/69) vs. 27.0% (27/100), p = 0.94]. Cox regression analysis identified preoperative PET/CT as an independent prognostic factor of OS and DFS (p = 0.002, HR = 0.69, 95% CI 0.54-0.88; p = 0.004, HR = 0.72, 95% CI 0.58-0.90).

Conclusion: Addition of preoperative [¹⁸F]FDG PET/CT was associated with superior DFS and OS in resectable cI-II NSCLC, which may result from accurate staging and stage-appropriate therapy.

Keywords: Computed tomography; NSCLC; Prognosis; Stage migration; [18F]FDG PET/CT.