Sonographic evaluation of endothelial function in letrozole and tamoxifen users.
OBJECTIVE
Studies have shown that women previously treated for breast cancer present fewer cardiovascular events, indicating a possible protective effect of tamoxifen treatment. The effects of these aromatase inhibitors on cardiovascular protection remain controversial. The aim of this study was to compare some cardiovascular risk markers among breast cancer survivors following treatment with tamoxifen group (TMXg), letrozole group (LTZg) or no endocrine treatment group (NETg).


METHODS
A total of 103 breast cancer survivors: 35 using TMXg, 34 using letrozole group (LTZg) and 34 using no endocrine treatment group (NETg) were evaluated. Ultrasonographic evaluation of brachial artery flow-mediated dilation (FMD), carotid intima-media thickness (IMT) and stiffness index (beta); blood total cholesterol, HDL and triglycerides were assessed.


RESULTS
All three groups presented similar values of HDL and IMT. TMXg showed the lowest total cholesterol (219.29+/-36.31mg/dL vs. 250.59+/-38.37mg/dL vs. 245.09+/-35.35mg/dL; TMXg vs. LTZg vs. NETg, respectively; p<0.01-ANOVA), the highest triglycerides (139.34+/-41.82mg/dL vs. 111.35+/-28.22mg/dL vs. 122.09+/-33.42mg/dL; p<0.01), the highest FMD (6.32+/-2.33% vs. 4.10+/-2.06% vs. 4.66+/-2.52%; p<0.01) and the lowest stiffness index (beta) (5.08+/-1.68 vs. 6.28+/-1.75 vs. 5.99+/-1.86; p=0.01). LTZg did not differ significantly from NETg on any evaluated parameter.


CONCLUSIONS
We did not observe any effect of LTZg on the evaluated cardiovascular risk parameters compared to NETg. As such, the observed difference on lipid values, stiffness index (beta) and FMD between women receiving tamoxifen and letrozole might be best attributed to the beneficial effect of tamoxifen than to a detrimental effect of letrozole.
Nastri
Carolina Oliveira
CO
Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo, Brazil. canastri@hotmail.com
Martins
Wellington Paula
WP
Ferriani
Rui Alberto
RA
Filho
Francisco Mauad
FM
Dos Reis
Francisco Jose Candido
FJ
D000368:Aged; D047072:Aromatase Inhibitors / Q000494:pharmacology*; D001916:Brachial Artery / Q000000981:diagnostic imaging; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000601:surgery; D002342:Carotid Artery, External / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000187:drug effects*; D005260:Female; D006801:Humans; D000077289:Letrozole; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D009570:Nitriles / Q000494:pharmacology*; D013629:Tamoxifen / Q000494:pharmacology*; D014230:Triazoles / Q000494:pharmacology*; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000187:drug effects; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000187:drug effects; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects
D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077289:Letrozole