Hormone therapy with tamoxifen reduces plasma levels of NT-B-type natriuretic peptide but does not change ventricular ejection fraction after chemotherapy in women with breast cancer

The objective of this study was to evaluate the effect of tamoxifen on the plasmaconcentration of NT-pro-B-type natriuretic peptide (NT-proBNP) in women undergoingchemotherapy for breast cancer and to correlate changes in NT-proBNP with the leftventricular ejection fraction (LVEF). Over a period of 12 months, we followed 60women with a diagnosis of breast cancer. The patients were separated into a groupthat received only chemotherapy (n=23), a group that received chemotherapy +tamoxifen (n=21), and a group that received only tamoxifen (n=16). Plasma levels ofNT-proBNP were assessed at 0 (T0), 6 (T6), and 12 (T12) months of treatment, andechocardiography data were assessed at T0 and T12. Plasma NT-proBNP levels wereincreased in the chemotherapy-only group at T6 and T12, whereas elevated NT-proBNPlevels were only found at T6 in the chemotherapy + tamoxifen group. At T12, thechemotherapy + tamoxifen group exhibited a significant reduction in the peptide tolevels similar to the group that received tamoxifen alone. The chemotherapy-onlygroup exhibited a significant decrease in LVEF at T12, whereas the chemotherapy +tamoxifen and tamoxifen-only groups maintained levels similar to those at thebeginning of treatment. Treatment with tamoxifen for 6 months after chemotherapysignificantly reduced the plasma levels of NT-proBNP and did not change LVEF in womenwith breast cancer.