Possible link between familial susceptibility to cancer and the level of oxidative stress in thyroid cancer patients

Abstract Background Hereditary cancer is estimated to account for up to 10% of the worldwide cancer burden; 5% of all thyroid cancers are thought to be genetic. Inheritance of a deleterious mutation in genes associated with a high lifetime risk of developing cancer. Cancer-predisposing genes can promote the initiation and progression of thyroid cancer by enhancing the activation of major signaling pathways through oxidative stress mechanisms. Aim Identification of the possible link between familial susceptibility to cancer and the level of oxidative stress in thyroid cancer patients. Methods Patients with thyroid cancer (with and without genetic predisposition) were investigated. Study participants were treated in Limited Liability Company (LLC) “Oncology Scientific Research Center” (Tbilisi, Georgia). The study group was collected between 2020 and 2021. In patients’ blood, the thyroid hormones content (free Triiodothyronine (fFT3), free Thyroxine (fFT4), bound Triiodothyronine (FT3), bound Thyroxine (FT4), Thyroid-stimulating hormone (TSH)), and oxidative stress intensity (total activity of non-enzymatic antioxidant system (TAA) and the lipid peroxidation product, malondialdehyde (MDA), content) were investigated. Results The difference in free and bound forms of T3 and T4 levels in the blood serum between patients with thyroid cancer (Group 2 and Group 3) and the control group (Group 1) was not statistically significant ( F 1,2 =0.5, p 1,2 =0.8, F 1,3 =2.31, p 1,3 =0.16). In patients with thyroid cancer the TSH level significantly increased compared to the control group (Group 1) (TSH (mean ± Std error): Group 1– 1.21 ± 0.12, Group 2–2.45 ± 0.11 ( F 1,2 =107, p 1,2 <0.001), Group 3–2.47 ± 0.17 ( F 1,3 =150, p 1,3 <0.001)) and the MDA levels increased by 4–5 fold. In patients with thyroid cancer from families with cancer aggregation(Group 2), the level of TAA statistically significantly decreased ( F 1 − 2 = 200; p 1 − 2 < 0.001), in patients without genetic predisposition to cancer(Group 3), the level of TAA did not change compared to the control (F 1 − 3 = 2.13; p 1 − 3 = 0.15), Conclusions Oxidative stress plays a critical role in tumorigenesis, and antioxidant/oxidant imbalance may contribute to the malignant transformation of normal tissue. In patients with familial susceptibility to cancer mutations of several genes, which are involved in the regulation of oxidative metabolism, may contribute to the disruption of the redox balance, increase the level of oxidative stress, and contribute to the development of thyroid cancer.