Vitamin D and Breast Cancer Biomarkers in Female Patients
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: vitamin D; placebo
Intervention description: Given orally; Given orally
Intervention MeSH terms: Vitamin D
Phase: Phase 3
Study type: Interventional
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 300.0
Sex: Female
Maximum age: 55 Years
Healthy volunteers: No
Keywords: breast cancer

Summary:

      RATIONALE: Vitamin D may help prevent breast cancer.

      PURPOSE: This randomized clinical trial is studying vitamin D and breast cancer biomarkers in
      female patients.
    

Eligibility criteria:

        1. Premenopausal women 55 years of age or younger with regular menstrual cycles (at least
             four cycles in the last six months). Women with fewer than 4 menses in the last 6
             months or who have had a hysterectomy with ovaries intact will be considered
             premenopausal if FSH level < 20.

          2. Women with breast density ≥ 25% (scattered fibroglandular densities or greater) are
             eligible.

          3. Prior Treatment

               1. Patients who are currently receiving hormone replacement therapy (estrogen or
                  progesterone); or are taking tamoxifen or raloxifene are not eligible. Women who
                  have taken these medications must have stopped for at least 4 months prior to
                  study entry.

                  Topical estrogen (eg, transdermal patches and vaginal estrogens) is allowed.

               2. Patients who are currently using hormonal contraception, should be taking it for
                  at least 4 months prior to study entry.

          4. Vitamin D Use

               1. Patients who are taking regular vitamin D supplementation (above 400 IUs daily)
                  and refuse or are unable to stop use are not eligible. Women who agree to stop
                  will need to do so for at least 6 months prior to registration.

               2. Patients may not start vitamin D supplementation after registration (regardless
                  of results of vitamin D testing) but they may continue vitamin D if they are
                  already taking 400 IUs daily or less and have been taking vitamin D for at least
                  6 months prior to baseline mammogram.

          5. Patients with a history of breast cancer (including DCIS) or ovarian cancer are not
             eligible.

          6. Patients with a history of breast implants or breast reduction are not eligible.

          7. Patients with two or more bone fractures in the past five years are not eligible.

          8. Patients with a diagnosis of osteoporosis with physician recommendation for treatment
             of low bone mass are not eligible.

          9. Patients known to have hyperparathyroid disease or other serious disturbances of
             calcium metabolism requiring intervention in the past 5 years are not eligible.

         10. Patients with a history of kidney stones (unless documented not to have been a calcium
             stone) are not eligible.

         11. Patients participating in a concurrent breast cancer chemoprevention trial are not
             eligible.

         12. Required initial laboratory values - Calcium < 10.5 mg/dL