FDG-PET for prediction of survival of patients with metastatic colorectal carcinoma

Background: The current study focuses on the prognostic value of pretreatment metabolic activity in metastases as measured with [ 18 F]fluorodeoxyglucose positron emission tomography (FDG-PET), as an indicator of survival in colorectal cancer. Patients and methods: In a prospective series of 152 patients with metastatic colorectal cancer, of whom 67 were treated with resection of metastases and 85 with chemotherapy, standardized uptake values (SUV) as measured with FDG-PET, were calculated prior to treatment. Survival probabilities were estimated by Cox proportional regression analysis. For Kaplan–Meier analysis SUV was stratified by the median value. Survival differences were assessed using the log-rank test. Results: SUV in metastases was a significant predictor for overall survival (hazard ratio 1.17, 95% confidence interval 1.06–1.30, P = 0.002), independent of the subsequent treatment. According to the median value of the patient population a low (SUV <4.26) and high uptake group (SUV >4.26) was defined. The median survival and the 2- and 3-year survival rates were 32 months, 59% and 45%, respectively, in the low-uptake group and 19 months, 37% and 28%, respectively, in the high-uptake group ( P = 0.017). Conclusion: A significant survival benefit was observed in patients with low FDG uptake in metastases of colorectal cancer.