Thursday, February 12, 2009
THURSDAY, Feb. 12 (HealthDay News) -- Despite recent epidemiologic evidence suggesting statins decrease breast cancer incidence, they had no activity in a rat model of mammary cancer, according to research published in the February issue of Cancer Prevention Research.
Ronald A. Lubet, of the National Cancer Institute in Bethesda, Md., and colleagues used a rat model of mammary cancer in which nearly half of the cancers express a mutated form of the Ha Ras oncogene. Two statins with unique lipophicilities, atorvastatin and lovastatin, were administered to the rats. The statins were given either as a single-agent or in combination with suboptimal doses of tamoxifen or bexarotene, a retinoid X receptor agonist.
Neither single-agent atorvastatin nor lovastatin significantly impacted the incidence or multiplicity of mammary cancer in the rats, the investigators found. Both low and high doses of each statin were evaluated, with similar results. Although either tamoxifen or bexarotene each reduced cancer multiplicity, their combination with either statin was not synergistic. Both statins significantly decreased the triglyceride levels that were increased in bexarotene-treated rats, without affecting the cancer prevention activity of bexarotene, the researchers report. This is important as current clinical use of bexarotene generally is administered in combination with a statin, the report indicates.
The results "clearly show the lack of efficacy of these statins following dietary dosing in two in vivo models of mammary cancer used routinely in screening for preventative agents," the authors conclude.
Diabetes & Endocrinology
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