Elaboration of a Model for Predicting Efficacy of Monoclonal Antibodies (Cetuximab and Bevacizumab) in Patients With Colorectal Cancer and Liver Metastases

Overview

Primary Objective: This trial is elaborating a model for rapidly predicting (day 21) the response to monoclonal antibodies anti-EGFR and anti-VEGF (cetuximab and bevacizumab) based on biological markers and/or functional imaging. The response to treatment is evaluated by the conventional method after 2 months (Response Evaluation Criteria in Solid Tumors \[RECIST\] criteria). Secondary Objectives: 1. This trial is also analyzing the correlation between the magnitude of response to treatment at 2 months (stabilization or objective response, RECIST criteria) and that of response observed after 6 months of treatment. 2. The organisational objective is to develop a tumour bank of metastatic colorectal cancer. Population: The population includes 252 male and female patients with metastatic colorectal cancer justifying the use of cetuximab or bevacizumab, with no heart disease. Techniques: Computed tomography (CT scan), functional imaging (ultrasound with SonoVue); molecular imaging (positron emission tomography \[PET\] with fluorodeoxyglucose F18 \[18-FDG\]); and biology and pathology on microbiopsy of liver metastasis are used. Outcome Criteria: The primary outcome is response to treatment with monoclonal antibodies according to RECIST criteria at two months. Studied Factors: Radiology: 1. CT scan: RECIST criteria (gold standard); 2. Ultrasound with SonoVue injection: 1 representative target (delay of contrast appearance, peak of rising, curve of increase and decrease of the signal, area under the curve, time of average transit). Nuclear Medicine: PET scan and 18-FDG (standard uptake values \[SUV\]) Molecular Characterization of Tumors: p53 status; microsatellite instability (MSI) status; expression of oncogenes; EGFR status; VEGF status; determination of FcgammaRIIIA polymorphisms Statistics: 1. Descriptive analyses; 2. Analysis of the appropriate threshold to measure: response to treatment by an ultrasound with SonoVue and by PET scan; correlation between response predicted by the ultrasound with SonoVue and the PET; conventional morphological CT at 2 months 3. Analysis of prognostic factors: 1. Evaluation of the role of each prognostic factor (pathology and imaging) on response to treatment; 2. Multivariate analysis of prognostic factors; 3. Analysis of the prognostic power of early response at 2 months on the response observed after 6 months of treatment.