Tamoxifen alters the plasma concentration of molecules associated with cardiovascular risk in women with breast cancer undergoing chemotherapy.

Objectives. The objective of this study was to evaluate the effect of tamoxifen on blood markers that are associated with cardiovascular risk, such as C-reactive protein (CRP), apolipoprotein A-1 (Apo-A), and apolipoprotein B-100 (Apo-B), in women undergoing chemotherapy for breast cancer. Methods. Over a period of 12 months, we followed 60 women with breast cancer. The women were divided into the following groups: a group that received only chemotherapy (n = 23), a group that received chemotherapy plus tamoxifen (n = 21), and a group that received only tamoxifen (n = 16). Plasma CRP levels were assessed at 0, 3, 6, and 12 months, and Apo-A and Apo B levels as well as the Apo-B/Apo-A ratio were assessed at 0 and 12 months. Results. We found increases in the plasma concentration of CRP in the chemotherapy alone and chemotherapy plus tamoxifen groups after 3 and 6 months of treatment (before the introduction of tamoxifen). However, after 12 months of treatment, women who used tamoxifen (the chemotherapy plus tamoxifen and tamoxifen alone groups) showed a significant reduction in CRP and Apo-B levels and a decrease in the Apo-B/Apo-A ratio. A significant increase in serum Apo-A levels was observed in the group receiving chemotherapy alone as a treatment for breast cancer. Conclusion. The use of tamoxifen after chemotherapy for the treatment of breast cancer significantly reduces the levels of cardiovascular disease risk markers (CRP, Apo-B, and the Apo-B/Apo-A ratio). The Oncologist 2012;17:499-507