Thyroid function following breast cancer chemotherapy: A systematic review

Background Chemotherapy, as a systemic therapy, is one of the most effective modalities for cancer treatment. However, the use of chemotherapeutic drugs in patients with breast cancer can lead to thyroid dysfunction. This systematic review summarizes the available data on thyroid function following breast cancer chemotherapy. Methods To illuminate the thyroid toxicities induced by different chemotherapy regimens in patients with breast cancer, a systematic search was done in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline in Scopus, Embase, PubMed and Web of Science electronic databases up to December 2018. On the basis of a set of prespecified inclusion and exclusion criteria, eight eligible articles providing data on thyroid function following chemotherapy in patients with breast cancer were included in the study. Results According to the obtained results, it was found that for most cases, the levels of triiodothyronine (T3), free T3 (FT3), thyroxin (T4) and free T4 (FT4) hormones decrease following breast cancer chemotherapy regimens used in these eligible studies. However, alteration of thyroid-stimulating hormone (TSH) level after breast cancer chemotherapy was not clear. Conclusion The findings showed that thyroid function and TSH hormone level can change in patients with breast cancer receiving different chemotherapy regimens.