RESUMO
ABSTRACT Thyroid cancer usually responds to surgical and ablative therapy, but when it's refractory the alternative lies in tyrosine kinase inhibitors that, in addition to harmful side effects, acts only in a palliative way. The concern for other therapeutic possibilities brought evidence on flavonoids, hypothesizing a possible strategy. This review aimed to organize a compilation of in vitro studies using polyphenol substances in TPC-1 (human papillary thyroid carcinoma cell line) summarizing it's results and describing the metabolic pathways involved. Articles were selected on PubMed, Google Scholar, LILACS, BVS and SciELO, using keywords "thyroid cancer", "flavonoids" and "TPC-1", until June 2022. 185 studies were selected. After identification and exclusion of duplicates and exclusion criteria applied, 11 original articles were evaluated. Of these, the findings of flavonoids added to TPC-1 were: inhibition of cell growth and viability, promotion of cell cycle arrest and induction of apoptosis. Polyphenolic compounds have antineoplastic properties by different mechanisms as shown in vitro, but the concentrations needed are above usual dietary consumption and the findings are limited to experimental cellular studies. Despite that, these results should be useful to guide further analysis aiming to reveal the real safety and efficacy of polyphenols in this scenario.