Evaluation of the Association Between CYP2D6 Genetic Polymorphisms and the Treatment Effect of Tamoxifen

Inclusion Criteria

• •Histologically or cytologically diagnosed stage IV or recurrent breast cancer patients according to American Joint Committee on Cancer (AJCC)
• •Positive estrogen receptor or Positive progesterone receptor.
• •Females at least 18 years of age.
• •Prior radiation therapy is allowed as long as the irradiated area is not the only source of measurable disease
• •Prior hormone therapy less than 2.
• •No history of Megace medication for recent 28 days
• •Performance status of 0, 1 and 2 on the ECOG criteria
• •Clinically measurable disease, defined as bidimensionally measurable lesions with clearly defined margins on x-ray, CT scan, MRI or physical examination. Lesions serving as measurable disease must be at east 1 cm by 1 cm, as defined by x-ray, CT scan, MRI, or physical examination
• •Bone only or pleural fluid only disease is included as long as evaluation for clinical benefit is possible
• •Estimated life expectancy of at least 12 weeks
• •Compliant patient who can be followed-up adequately.
• •Adequate hematologic (WBC count 3,000/mm3, platelet count 100,000/mm3), hepatic (bilirubin level 1.8 mg/dL, AST, ALT 1.5xULN, albumin 2.5 g/dL), and renal (creatinine concentration 1.5 mg/dL) function.
• •Informed consent from patient or patient's relative
• •Childbearing women should use non-hormonal contraceptive method