The present invention provides methods for improving the progression-free survival of a patient suffering from gastrointestinal cancer, in particular, metastatic colorectal cancer (mCRC), by treatment with bevacizumab (Avastin ® ) in combination with a chemotherapy regimen by determining the expression level of one or more of VEGFA and HER2 relative to control levels in patients diagnosed with gastrointestinal cancer, in particular, metastatic colorectal cancer (mCRC). The present invention further provides for methods for assessing the sensitivity or responsiveness of a patient to bevacizumab (Avastin ® ) in combination with a chemotherapy regimen, by determining the expression level of one or more of VEGFA and HER2 relative to control levels in patients diagnosed with gastrointestinal cancer, in particular, metastatic colorectal cancer (mCRC).
