Objectives: Subcellular alteration of thyroid hormones (THs) signaling is proposed in many types of cancers. Some studies show deiodinase type 3, as an oncofetal protein, re-expresses in some cancer types. Therefore, we aimed to investigate the product of this enzyme, reverse triiodothyronine (rT3) in serum of newly diagnosed colorectal cancer (CRC) patients.
Methods: In this cross-sectional study, blood from 38 laboratory-confirmed cases was taken, and serum levels of rT3, total T3 (triiodothyronine), total T4 (thyroxine), free T3, free T4, and thyroid-stimulating hormone (TSH) were detected by using an enzyme-linked immunosorbent assay.
Results: The results illustrated that rT3 and free T3 levels increased in patients with early stages of colorectal cancer, despite normal levels of total T3, total T4, free T4, and TSH.
Conclusion: The elevation of rT3 in CRC patients can probably be due to the re-expression of deiodinase type 3 in CRC. Further research is needed to study the role of intracellular THs modulation in CRC and its impact on CRC treatment.
Keywords: Thyroid hormones; colorectal neoplasms; reverse triiodothyronine; thyrotropin; thyroxine; triiodothyronine.