Abstract
Study question
Does radioactive iodine (RAI) treatment in premenopausal women with differentiated thyroid cancer (DTC) affects ovarian reserve, as evaluated by anti-Müllerian hormone (AMH), antral follicle count (AFC) and follicle-stimulating hormone (FSH)?
Summary answer
AMH concentrations decreased at three, six and 12 months following RAI treatment in women with DTC, whereas no difference was observed regarding FSH.
What is known already
Thyroid cancer is the third most common type of female malignancy and DTC is the most common histopathological type. Thyroidectomy constitutes the mainstay of treatment for DTC, followed by administration of RAI, which acts as an adjuvant therapy to destroy residual cancerous thyroid tissue. However, the effect of RAI on ovarian reserve of these women, as assessed by AMH, AFC and FSH, remains controversial.
Study design, size, duration
A systematic review and meta-analysis was performed aiming to identify studies evaluating the effect of RAI treatment on ovarian reserve in women with DTC. For this purpose, a literature search in the electronic databases PubMed, Scopus and CENTRAL was carried out until 06/12/2020. The primary outcome measure was the effect of RAI on ovarian reserve, as evaluated by AMH, AFC and FSH.
Participants/materials, setting, methods
Studies were eligible if they included premenopausal women with DTC, treated with a single RAI dose and assessed for at least one marker of ovarian reserve repeatedly within 12 months post-RAI.Meta-analysis of weighted data was performed using random effects model. Results were reported as weighted mean difference (WMD) with 95% confidence interval (CI).
Main results and the role of chance
Four prospective eligible studies, published between 2005 and 2020, were eligible for the meta-analysis, evaluating a total of 154 women. The number of participants ranged from 24 to 50. The single dose of RAI used to treat DTC ranged from 50 to 150 mCi. AMH concentrations decreased at three (WMD -1.66 ng/ml, 95% CI -2.42 to -0.91, p < 0.0001; I2 0%), six (WMD -1.58 ng/ml, 95% CI -2.63 to -0.52, p = 0.003; I2 54.7%) and 12 months (WMD -1.62 ng/ml, 95% CI -2.02 to -1.22, p < 0.0001; I2 15.5%) following a single RAI dose compared with baseline (three studies; n = 104). With respect to FSH concentrations, no difference was observed at six (WMD +3.29 IU/l, 95% CI -1.12 to + 7.70, p = 0.14; I2 96.8%) and 12 months (WMD +0.13 IU/l, 95% CI -1.06 to + 1.32, p = 0.83; I2 55.2%) post-RAI compared with baseline (two studies; n = 83). No data on AFC was available.
Limitations, reasons for caution
The small number of studies and patients included, as well as the lack of data on AFC may have compromised the validity of the conclusions drawn. Moreover, subgroup analysis according to female age was not feasible, due to the lack of relevant data.
Wider implications of the findings
The negative effect of RAI on ovarian reserve in premenopausal women with DTC, as indicated by the decreased AMH, should be confirmed by data on AFC, which are currently not available. These findings necessitate close monitoring of ovarian reserve in such women, counselling them regarding the need for fertility preservation.
Trial registration number
N/A
Ablation rate after radioactive iodine therapy in patients with differentiated thyroid cancer at intermediate or high risk of recurrence: a systematic review and a meta-analysis