This study evaluates vaginal microbiome as a biomarker to improve vaginal and sexual health in women with breast cancer receiving endocrine therapy. Breast cancer is the most common cancer in United States women, aside from skin cancers. Endocrine therapy is standard treatment for 70% of invasive breast cancers, significantly affecting sexual health and often causing women to change their course of treatment or cease sexual activity. Changes in the vaginal microbiome, which is the collection of all microorganisms, such as bacteria, fungi, and viruses, that naturally live on and inside the body, are implicated in menopausal-related sexual health symptoms, but the vaginal microbiome (and associated immune responses) has not been explored as a biomarker for sexual health changes in hormone-related sexual health symptoms in breast cancer. A biomarker is a biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. Ribonucleic acid (RNA)-sequencing is a cost-effective method to analyze both human and microbial transcripts. The RNA that is sequenced from a standard biological sample such as a swab is a snapshot of the expression of many different cells and can be used to simultaneously measure the quantities of microbes, the overall expression of the human host, and the quantities of immune cells. Information gathered from this study may help researchers establish the vaginal microbiome as a biomarker and therapeutic target to improve the vaginal and sexual health of women with breast cancer receiving endocrine therapy.

PRIMARY OBJECTIVE:

I. Determine whether individuals who experience vaginal dryness have a distinct microbiome prior to treatment from those who do not in a sample of breast cancer survivors initiating endocrine therapy.

EXPLORATORY OBJECTIVE:

I. Explore potential mechanisms of microbiome-associated vaginal toxicity through correlation with host gene expression and deconvolved immune cell abundances.

OUTLINE: This is an observational study.

Participants undergo vaginal specimen self-collection via vaginal swab collection kit, complete questionnaires, and have medical records reviewed on study.

Inclusion Criteria:

• Women ages 18 years and older
• Non-metastatic, estrogen and/or progesterone positive, human epidermal growth factor (HER) 2 negative breast cancer who will be receiving endocrine therapy, including tamoxifen, aromatase inhibitor, or ovarian suppression
• Endocrine positive women who have received chemotherapy (adriamycin and cytoxan + taxol; taxotere and cytoxan) will still be eligible but must have completed their treatment

Exclusion Criteria:

• Triple negative breast cancer patients
• Human epidermal growth factor (HER) 2 positive breast cancer patients
• Metastatic disease

Patients with breast cancer receiving endocrine therapy at the Stephanie Spielman Comprehensive Breast Center (SSCBC) at the Ohio State University Medical Center.