Letter to the Editor

Abstract

In reply: We thank Drs. Swift and West for their interest in our article. We agree that the weak power and the short-term trial do not allow definitive and clear conclusions, so that further and longer studies are necessary. We believe that three new aspects of our pilot study have to be considered. The first one is that the examined parameters have been tested in the treated group, which have shown a good absorption of the soy extract; this is extremely important because some conflicting results obtained from other studies could be due to the high level of heterogeneity of the soy derivatives utilized and to the individual variability regarding the intestinal absorption of the phytoestrogens, given via the diet. 1 Moreover, inadvertent use of dietary isoflavones in the placebo group may justify a large placebo response. 2 In regard to the endometrial safety of soy, we believe that our preliminary results, based on this short-term trial, are consistent either with ultrasonic data [endometrial thickness (Control group: baseline to week 6, NS; week 6–10, p < 0.001 by ANOVA. Treated group: baseline to week 6, NS; week 6–10, p < 0.001 by ANOVA)] or with vascular data [uterine pulsatility index (Control group: baseline to week 6, NS; week 6–10, p < 0.001 by ANOVA. Treated group: baseline to week 6, NS; week 6–10, p < 0.01 by ANOVA)]. Last but not least, the study design examines the possibility or hypothesis that phytoestrogens could have an antagonist role in comparison with estrogen therapy on the genital tract, as commented by Clarkson. 3 We suggest that these aspects have to be verified by further randomized clinical studies to give a scientific rigor for this alternative and “natural” treatment. Giovanni Scambia MD Daniela Mango MD Riccardo Anselmi Angeli MD Salvatore Mancuso MD