Table 1.

Description of the agents used in these studies.

AgentDescriptionChemopreventive activity in prior mammary cancer studies (12–15)
TamoxifenSERM that binds ER alpha and inhibits the stimulatory effects of estrogen in ER+ breast cancers. Has both therapeutic and preventive activity clinically. The dose employed in these studies is at the HED.Yes
VorozoleSmall-molecule competitive inhibitor of aromatase (CYP 27) that is similar to clinically employed letrozole and anastrozole. Aromatase inhibitors (letrozole and exemustane) are used clinically in therapy and are effective in clinical prevention studies.Yes
TargretinPure RXR agonist employed clinically in the treatment of CTCL. The dose used in these studies is less than the HED for CTCL.Yes
GefitinibSmall-molecule competitive inhibitor of EGFR1. Effective in human ER+ tumors and effective in MNU model at roughly half of the HED.Yes
MetforminUsed to control blood sugar levels in type 2 diabetics. Its mechanism of action is unclear. The dose employed in these studies is approximately equivalent to the commonly employed human dose of 1,500 mg.No
LipitorCompetitive HMG CoA reductase inhibitor used to lower cholesterol levels. The dose employed in these studies is approximately 2–4× higher than that typically used in humans.No
NaproxenNSAID that competitively inhibits COX 1/2. It is a highly effective chemopreventive agent in colon and bladder cancer models. The dose employed in these studies is approximately equivalent to 350 mg in humans.No
• Abbreviation: CTCL, cutaneous T-cell lymphoma.