Background: An increasing proportion of patients with liver CAM are undergoing hepatic resection with curative intent. Detection of occult metastastic disease is important in this setting, and PET/CT is used to identify patients with either inoperable, or limited resectable extrahepatic disease not identified with conventional imaging. We recently reported the results related to the primary objective of PETCAM, a randomized trial for patients with resectable liver CAM, where 7.6% had a change in management based on PET/CT (ASCO 2011). As a secondary objective, we examined whether patients undergoing PET/CT derived a survival benefit, as they may be considered to be better selected.
Methods: PETCAM was a multicenter trial with 404 subjects randomized 2:1 to receive PET/CT or no PET/CT once they were assessed by a hepatobiliary surgeon to have resectable CAM. Subjects were followed over 4 years for overall survival (OS). As well as the intervention, we considered the SUV, Fong Score and other baseline factors as predictors for OS.
Results: After a median 2.8 years of follow-up, 107 of the 404 (26%) study subjects had died. The 270 PET/CT subjects [and the 245 of these who underwent surgery] showed no statistically significant survival advantage over the 134 No PET/CT subjects [123 who underwent surgery] with a hazard ratio (HR) of 0.85, 95% confidence interval (CI): 0.57 to 1.3; p=0.41 [HR=0.81, 95% CI: 0.52 to 1.3; p=0.34]. Fong score was a strong predictor of OS for all patients (HR=1.4, 95% CI: 1.1 to 1.6), and for those who had surgery (HR=1.4, 95% CI, 1.1 to 1.7). In the PET/CT arm, SUV is strongly predictive of OS [HR per unit SUV increase =1.11, 95% CI: 1.05 to 1.18; p=0.0007.
Conclusions: The addition of PET/CT had no effect on improving overall survival for patients who did or did not have hepatic resection for CAM. SUV is strongly predictive of survival for patients who had PET/CT, and Fong score is predictive of survival for all patients. The overall role of PET/CT in patients with resectable CAM appears limited and should be reevaluated in the current era of comparative effectiveness research and health care cost containment.