Changes in Breast Cancer Biomarkers Using Synergistic Prostaglandin Inhibitors

This is a biomarker study with the goal of measuring changes in protein and RNA expression. This study is not intended for use in diagnosing, mitigating, treating, curing, or preventing disease.

66 women at high risk for breast cancer (gail risk >/= 1.66% for 5 year risk, or personal or family history)will be recruited and enrolled. 22 women will be randomized into each arm, with anticipation of 2 women in each group will not be evaluable, leaving 20 in each group for evaluation.

A combination of vitamin D and celecoxib act synergistically to decrease breast cancer risk by decreasing cell proliferation in the mammary epithelium through their action on prostaglandin synthesis and metabolism.

Specific Aims:

In women at increased breast cancer risk, determine the effect of vitamin D, with or without celecoxib, on

PG synthesis and metabolism, through the measurement of 15-PGDH, COX-2, and PGE2 in the breast

Rationale: 1,25(OH)2D, the active form of vitamin D, has been shown in vitro to decrease PGE2 both by interfering with its production and by increasing its breakdown, leading to lower cell proliferation. Celecoxib potentiated the antiproliferative effect, allowing a much lower dose of each agent when used in combination than in isolation.

Proliferative activity in the breast, as measured by Mammary Ductoscopy (MD) cell morphology

Rationale: Both MD and Nipple Aspirate Fluid (NAF) contain ductal epithelial cells, but MD samples contain more cells for cytologic review than NAF. Findings on MD cytology correlate with likelihood of breast cancer (2), NAF cytology relates to breast cancer risk and improves risk stratification (3), and bioactive food components can alter NAF cytology (4).

Circulating levels of 25(OH)D, 1,25(OH)2D, and celecoxib, and determine if the levels of these compounds correlate with response to markers of PG synthesis and metabolism or cell proliferation.