Positron Emission Tomography Combined With Computed Tomography vs. No Positron Emission Tomography Combined With Computed Tomography for the Management of Patients With Resectable Colorectal Cancer Liver Metastases and Synchronous Extrahepatic Disease

INTRODUCTION: Selected patients with colorectal cancer liver metastases (CRLM) and synchronous extrahepatic disease (EHD) are considered for surgery. OBJECTIVES: To evaluate the change in surgical management and long-term survival (disease-free survival [DFS] and overall survival [OS]) for patients with CRLM and EHD who undergo positron emission tomography combined with computed tomography (PET-CT) vs no PET-CT. METHODS: Patients with CRLM were enrolled in a trial evaluating the effect of PET-CT (vs no PET-CT) on surgical management, DFS, and OS. This is a sub-study of the trial, including only patients with synchronous EHD. Cox proportional hazard models were used to calculate risks for recurrence and death. Survival were described by Kaplan-Meier method and compared with log-rank test. RESULTS: Of 25 patients with EHD (PET-CT arm: 14/270 (5%) and no PET-CT arm: 11/134 (8%)), PET-CT changed surgical management in 14%, all of which avoided liver resection due to more extensive disease. Complete metastasectomy was achieved in 36% (5/14) and 72% (8/11), respectively. Respectively, PET-CT vs no PET-CT had statistically similar median DFS, 5.6 months (95% confidence interval (CI) 3.6-18) vs 7.6 months (95% CI 2.9-15) and median OS, 42 months (95% CI 25-48) vs 29 months (95% CI 17-41). EHD was associated with worse DFS (hazard ratio HR = 1.89, 95% CI 1.41-2.52) and OS (HR = 2.47, 95% CI 1.6-3.83). CONCLUSIONS: Preoperative PET-CT for the management of resectable CRLM did not improve long-term outcomes among patients who had synchronous EHD; however, it changed surgical management in a relatively significant proportion of patients.