[1055] Effect of anastrozole on cholesterol fractions in postmenopausal women with high risk of breast cancer: results from IBIS-II breast cancer prevention study.
Singh S, Richmond B, Howell A, Cuzick J.. Wolfson Institute of Preventive Medicine, Charterhouse Square, London, United Kingdom; St Mary
s Hospital, Praed Street, London, United Kingdom; University of Manchester, Manchester, United Kingdom
Background: The impact of aromatase inhibitors (AIs) on cholesterol fractions is of increasing concern in postmenopausal women recieving AIs in a prevention setting, as some adjuvant trials have reported increased incidence of cardiovascular diseases. No data is available on the impact of AIs in well women in a prevention setting and very little is availble for anastrozole in any setting.
Material and Method: IBIS-II is a multicentre randomised placebo controlled trial of 6000 postmenopausal women aged 40-70 years, who are at increased risk of breast cancer. The assessments of total cholesterol, high density lipoprotein (HDL) and apoprotiens Apo B and A1 were measured on baseline and one year follow-up samples.
Results: Data from 141 participants were included in the statistical analysis. There was a slightly increased mean change in HDL levels for the anastrozole group compared to placebo although this was not significant. The difference in the mean changes between anastrozole and placebo were 0.0 (95% CI, -0.63, 0.61), p-value = 0.98. For both cholesterol and triglycerides, there was a small increase in levels in the placebo group compared to anastrozole although this difference in mean changes was not significant at the 5% significance. The mean changes at 95% CI were 0.15 (-0.11, 0.41) p= 0.2 and 0.05 (-0.18,0.29) p = 0.65 for cholesterol and triglycerides respectively.
Discussion: These data are reassuring about the effect of anastrozole on cholesterol fractions. No significant difference was seen for any fractions. If AIs do have any effect on cardivascular disease, it is likely to be mediated by mechanisms not related to cholesterol levels. These data will be updated at the time of meeting.
Thursday, December 14, 2006 5:00 PM
Poster Session I: Risk and Prevention: Prevention (5:00 PM-7:00 PM)