Trial Information

Breast Cancer Prevention Using Synergistic Prostaglandin Inhibitors (The Vitamin D/Celecoxib Study)

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

1. 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.

2. 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).

3. 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.