Overview CYP19 Genetic Polymorphism & Aromatase Inhibitor(AI) Status: Unknown status Trial end date: 2010-09-01 Target enrollment: Participant gender: Summary The purpose of this study is to investigate the relationship between the side effects(especially arthralgia and arthritis) which appear in the patients who are prescribed aromatase inhibitor(AI) and the CYP19 genetic polymorphisms. Details Lead Sponsor: Korea University Anam HospitalCollaborator: Korea UniversityTreatments: AnastrozoleAromatase InhibitorsLetrozole