The impact of androgen deprivation therapy and novel hormonal therapy on thyroid hormone levels in prostate cancer patients: a systematic review and meta-analysis.

[BACKGROUND] Although androgen deprivation therapy (ADT) and novel hormonal therapy (NHT) have improved the prognosis of prostate cancer (PC), the effect of ADT/NHT on thyroid hormone (TH) levels is highly controversial. We performed a systematic review and meta-analysis of peer-reviewed studies to investigate the effects of ADT/NHT on TH levels in PC patients.

[METHOD] Medical literature databases such as PubMed, Web of Science and Metstr were systematically searched for all potentially related clinical studies from their inception to July 10, 2025. The quality of the studies included in the review was evaluated using RevMan version 5.3 for the meta-analysis.

[RESULTS] The systematic review and meta-analysis were based on 413 cases selected from three publications. No significant difference in thyroid stimulating hormone (TSH) levels was observed between the ADT and control groups (MD 0.23 [95% CI -0.01-0.48]; p = 0.06, I = 0%), but a significant difference in FT4 levels between the ADT and control groups was observed (MD -0.77 [95% CI -1.50--0.03]; p = 0.04, I = 57%).

[CONCLUSIONS] For the first time, we showed no significant difference in the TSH level between the two groups, which might indicate that the TSH level was not affected by ADT in PC patients. Notably, in European countries, patients with long-term ADT were more likely to have lower FT4 levels than non-ADT patients were, but interestingly, all FT4 levels were within their reference intervals.