The goal of this interventional study is to evaluate the effect of Intravaginal Prasterone for the treatment of moderate to severe symptoms of genitourinary syndrome (GSM) due to natural, surgical or treatment-induced menopause and the effect on the quality of life, including sexual function and mood well-being, in women with Breast Cancer. A sample size of 95 patients will be needed to show that the proportion of women showing symptom improvement is greater than 50%. Subjects will be followed up at four weeks and twelve weeks of treatment. One and three-month outcomes will be provided after the end of treatment. Comparison between menopausal women with previous breast cancer that have finished hormonal therapy or with ER negative breast cancer and women currently under endocrine therapy with AIs will be performed.

Inclusion Criteria:

• Histologically confirmed breast cancer, completely excised
• Natural or iatrogenic menopausal status
• No evidence of distant metastasis
• Self-identified moderate to severe symptoms of genitourinary syndrome
• Normal kidney and liver function
• Written Informed Consent signed and dated by patient
• Negative Papanicolau (Pap) Smear Cytology Test within 1 year prior to enrollment

Exclusion Criteria:

• Vaginal or uterine bleeding of unknown origin
• Current diagnosis of any non-breast malignancy
• Metastatic disease
• Currently on chemiotherapy
• Currently on treatment with tamoxifen
• Mentally incompetent or evidence of active substance or alcohol abuse
• Endometrial hyperplasia
• Pregnancy or lactation
• Currently use of other vaginal therapy for the same purpose (if present, they have to be stopped 15 days before baseline visit)
• Clinically significant metabolic or endocrine disease not controlled by medication