Effect of PET-CT on disease recurrence and management in patients with potentially resectable colorectal cancer liver metastases. Long-term results of a randomized controlled trial.

Background: Preoperative evaluation of resectable colorectal cancer liver metastases with positron emission tomography (PET) combined with computed tomography (PET-CT) is used extensively. The PETCAM trial evaluated the effect of PET-CT (intervention) vs no PET-CT (control) on surgical management. PET-CT resulted in 8% change in surgical management, therefore, we aimed to compare long-term outcomes (disease-free [DFS], overall survival [OS]).

Methods: Trial recruitment (2005-2010) had prospective follow-up until 2013. Events from 2013 to 2017 were collected retrospectively. Survival was described by the Kaplan-Meier method and compared with log-rank test. Oncologic risk factors were calculated using Cox proportional hazard models.

Results: Among 404 patients randomized, there were no differences in DFS (hazard ratio [HR] = 1.13; 95% confidence interval [CI], 0.89 to 1.43) or OS (HR, 1.02; 95% CI, 0.78-1.32) between groups. For all patients randomized, median DFS (PET-CT vs no PET-CT) was 16 months (95% CI, 13-18) and 15 months (95% CI, 11-22), P = .33. For patients who underwent liver resection (n = 368), DFS (17 vs 16 months, P = .51) and OS (58 months vs 52 months, P = .90) were similar between groups, respectively. Risk factors for DFS and OS were age, tumor size, node-positive disease, extrahepatic metastases and disease-free duration.

Conclusion: Preoperative PET-CT changes surgical management in a small percentage of cases, without effect on recurrence rates or long-term survival.