Effect of Pregnancy and Menopause on Micropapillary Thyroid Carcinomas During Active Surveillance

BACKGROUND: The effect of estrogen and beta-human chorionic gonadotropin on micropapillary thyroid carcinoma (mPTC) is not defined. Pregnancy and menopause could represent critical moments during active surveillance (AS) for women with mPTC. OBJECTIVE: To evaluate the effect of either pregnancy or menopause on growth of mPTCs on AS. PATIENTS AND METHODS: Women with mPTC on AS who became pregnant or underwent menopause during AS were evaluated in this retrospective observational study. The primary outcome was disease progression according to the AS protocol. The secondary outcome was the shrinkage of mPTCs. We compared the menopause group of patients with 2 unmatched control groups: (1) the pre-menopause group of patients on AS who had not experienced menopause yet and (2) the post-menopause group of patients who started AS while already in menopause. RESULTS: Five patients who became pregnant and 9 who underwent menopause during AS were enrolled. No patient from either group had a disease progression, and all pregnant patients showed stable disease after pregnancy. Four patients of the menopause group (44%) experienced mPTC shrinkage. The percentage of patients with mPTC shrinkage was significantly higher in the menopause group than in the 2 control groups. CONCLUSIONS: mPTC AS appears to be safe and feasible in patients who become pregnant or undergo menopause during surveillance. Our data suggest a possible association between menopause and mPTC shrinkage during AS.