Baseline Hemoglobin and Liver Function Predict Tolerability and Overall Survival of Patients Receiving Radioembolization for Chemotherapy-refractory Metastatic Colorectal Cancer

Background: Patients with liver metastatic colorectal cancer (mCRC) often benefit from receiving Y-microsphere radioembolization (RE) administered via the hepatic arteries. Prior to delivery of liver-directed radiation, standard laboratory tests may assist in improving outcome by identifying correctable pre-radiation abnormalities.

Methods: A database containing retrospective review of consecutively treated patients of mCRC from July 2002 to December 2011 at 11 US institutions was used. Data collected included background characteristics, prior chemotherapy, surgery/ablation, radiotherapy, vascular procedures, Y treatment, subsequent adverse events and survival. Kaplan-Meier estimates compared the survival of patients across lines of chemotherapy. The following values were obtained within 10 days prior to each RE treatment: haemoglobin (HGB), albumin, alkaline phosphatase (Alk phosph), aspartate aminotransferase (AST), alanine transaminase (ALT), total bilirubin and creatinine. Common Terminology Criteria Adverse Events (CTCAEs) 3.0 grade was assigned to each parameter and analysed for impact on survival by line of chemotherapy. Consensus Guidelines were used to categorize the parameter grades as either within or outside guidelines for treatment.

Results: A total of 606 patients (370 male; 236 female) were studied with a median follow-up was 8.5 mo. (IQR 4.3-15.6) after RE. Fewer than 11% of patients were treated outside recommended RE guidelines, with albumin being the most common, 10.5% grade 2 (<3-2.0 g/dL) at time of RE. All seven parameters showed statistically significant decreased median survivals with any grade >0 (P<0.001) across all lines of prior chemotherapy. Compared to grade 0, grade 2 albumin decreased overall survival 67%; for grade 2 total bilirubin a 63% drop occurred, and grade 1 HGB resulted in 66% lower median survival.

Conclusions: Review of pre-RE laboratory parameters may aid in improving median survivals if correctable grade >0 values are addressed prior to radiation delivery. HGB <10 g/dL is a well-known negative factor in radiation response and is easily corrected. Improving other parameters is more challenging. These efforts are important in optimizing treatment response to liver radiotherapy.