Endocrine Abstracts

Introduction: Radiodine (¹³¹I) is widely used in the treatment of patients with thyroid cancer. This therapy is associated with some adverse effects including possible impairment of ovarian function and earlier menopause.

Objective: The aim of this study was to evaluate female fertility after treatment with ¹³¹I of differentiated thyroid cancer (DTC).

Methods: We retrospectively analysed 250 women with DTC treated with¹³¹I. We selected those who had received the first ¹³¹I before or at the age of 45 and who still presented regular menses on this occasion. Hysterectomized patients and those submitted to external pelvic radiotherapy or chemotherapy before menopause were excluded. Only 33 women filled these criteria. The control group consist of 64 women with multinodular goiter (MNG) in whom we applied the same criteria. Age at menopause was defined by the absence of menses for 6 months. We also investigated smoking habit and thyroid autoimmunity. The t student, linear regression and Kruskal-Wallis test were used for statistical analysis. A P value of <0.05 was considered significant.

Results: The age at menopause was 49.3±3.8 years in the group of women with DTC and 49.41±3.8 years in the group with MNG(P=ns). We didn`t find any difference between the age at menopause and the number of therapies. We found a marginally significant correlation (R²=0.116; P=0.05) between the cumulative dose of ¹³¹I and the age at menopause.

Conclusion: In our study the age at menopause was similar between the 2 groups. We verified a correlation between the cumulative dose of ¹³¹I and age at menopause: higher doses were associated with earlier menopause.