Inclusion Criteria:

- Postmenopausal woman with early breast cancer who are prescribed with anastrozole as
adjuvant endocrine therapy under the routine clinical practice.

- Histologically or cytologically proven to be HR+(ER or PR +)

- No other concomitant endocrine therapy such as estrogen therapy or selective estrogen
receptor modulators

- Provision of written informed consent

Exclusion Criteria:

- Recurrence of breast cancer

- Known hypersensitivity to anastrozole or to any of its excipients

- Any severe concomitant condition which makes it undesirable for the patient to
participate in the trial or which would jeopardize adherence with the trial protocol:
Amenorrhea<12 months and a intact uterus; Previous inclusion in the present study;
Participation in a other clinical study during the last 30 days·

- Women who does not agreed to participate the program