Insomnia is common in Breast cancer patients during adjuvant therapy with aromatase inhibitor.

However it is difficult to establish whether it is due to the knowledge of the disease or the treatment administred.

The investigators designed a cohort study in which questionnaires for the assessment of sleep quality (Pittsburgh Sleep Quality Index and Insomnia Severity Index), anxiety (State and Trait Anxiety Inventory), depression (Beck Depression Inventory), for the quality of life in general (Functional Assessment of Cancer Therapy) and for the evaluation of RLS (Restless Legs Syndrome Rating Scale) will be prospectively administered to patients with early breast cancer at baseline and during adjuvant treatment with aromatase inhibitors.

As secondary aims the investigators will also evaluate dietary and lifes' factors, born turn over and BMI.

Inclusion Criteria:

• Women with a histological diagnosis of invasive operated breast cancer (any pT, any pN)
• Women with more than 60 years
• Women less than 60 years with amenorrhea for at least 12 months and FSH and estradiol values in the range of menopause
• Signature of written informed consent.

Exclusion Criteria:

• Locally advanced or metastatic disease (M1)
• A history of breast cancer or other cancers diagnosed in the last 10 years, to exception of basal cell carcinoma or squamous cell carcinoma of the skin or carcinoma in situ of the cervix
• History of severe osteoporosis before the diagnosis of breast cancer
• Bisphosphonate therapy before the diagnosis of breast cancer
• Other serious medical conditions that could limit the ability of the patient to participate in the study

Postmenopausal Women with early stage endocrine responsive breast cancer