Factors Affecting Oncologic Outcomes of 90Y Radioembolization of Heavily Pre-Treated Patients With Colon Cancer Liver Metastases

One-year overall survival prediction nomogram included 6 easy-to-obtain pre Yttrium-90 radioembolization parameters and provided good prediction of overall survival post Yttrium-90 radioembolization. This can be useful for pretreatment patient stratification and counseling of heavily pretreated patients with colorectal cancer liver metastases. Baseline maximum standardized uptake value predicted liver progression-free survival.

Introduction: The purpose of this studywas to identify predictors of overall (OS) and liver progression-free survival (LPFS) following Yttrium-90 radioembolization (RAE) of heavily pretreated patients with colorectal cancer liver metastases (CLM), as well as to create and validate a predictive nomogramfor OS. Materials and Methods: Metabolic, anatomic, laboratory, pathologic, genetic, primary disease, and procedure-related factors, aswell as pre- and post-RAE therapies in 103 patients with CLM treated with RAE from September 15, 2009 to March 21, 2017 were analyzed. LPFS was defined by Response Evaluation Criteria In Solid Tumors 1.1 and European Organization for Research and Treatment of Cancer criteria. Prognosticators of OS and LPFS were selected using univariate Cox regression, adjusted for clustering and competing risk analysis (for LPFS), and subsequently tested in multivariate analysis (MVA). The nomogram was built using R statistical software and internally validated using bootstrap resampling. Results: Patients received RAE at a median of 30.9 months (range, 3.4-161.7 months) after detection of CLM. The median OS and LPFS were 11.3 months (95% confidence interval, 7.9-15.1 months) and 4 months (95% confidence interval, 3.3-4.8 months), respectively. Of the 40 parameters tested, 6 were independently associatedwithOS inMVA. These baseline parameters included number of extrahepatic disease sites (P 80 was 90% and 10%, respectively. Bootstrap resampling showed good discrimination (optimism corrected c-index = 0.745) and calibration (mean absolute prediction error = 0.299) of the nomogram. Only baseline maximumstandardized uptake value was significant in MVA for LPFS prediction (P <.001; SHR = 1.06). Conclusion: The developed nomogram included 6 pre-RAE parameters and provided good prediction of survival post-RAE in heavily pretreated patients. Baseline maximum standardized uptake value was the single significant predictor of LPFS. (C) 2018 Published by Elsevier Inc.