A Retrospective Cohort Study of Infusion Reactions Due to Vectibix

Inclusion Criteria * All patients treated with at least one treatment of Vectibix(Panitumumab) from February 2004 -April 2009 are eligible for the study. Patients may or may not have had an infusion reaction to Vectibix (Panitumumab). Major infusion reactions are defined as rapid onset airway obstruction(bronchospasm, stridor, hoarseness), urticaria, erythema, and/or hypotension, anaphylaxis. Minor infusion reactions are defined as transient flushing or rash, urticaria, dyspnea, drug fever. * Patients who have received treatment with an EGFR in the past are eligible. Exclusion Criteria * There will be no exclusions based on age, sex, medical history, or use of concomitant therapies. All charts will be abstracted for the same information, through completion of the last chemotherapy cycle.