Abstract: The present invention provides methods for individualizing chemotherapy for cancer treatment, and particularly for evaluating a patient's responsiveness to one or more epidermal growth factor receptor (EGFR) inhibitors prior to treatment with such agents. Particularly, the invention provides an in vitro chemoresponse assay for predicting a patient's response to a monoclonal EGFR antibody, such as cetuximab. The method generally comprises culturing malignant cells from a patient's specimen (e.g., biopsy specimen), contacting the cultured cells with a monoclonal EGFR antibody that is a candidate treatment for the patient, and evaluating the cultured cells for a response to the drug. In certain embodiments, monolayer(s) of malignant cells are cultured from explants prepared by mincing tumor tissue, and the cells of the monolayer are suspended and plated for chemosenstivity testing.