Possible Markers for Distinguishing benign and Malignant Thyroid Tumors and Predicting Malignancy in Patients with Genetic Predisposition to Cancer.

[BACKGROUND] We hypothesized that mutations in several genes disrupt oxidative metabolism, increasing the risk of developing tumors and their malignancy in patients with a family predisposition to cancer. The purpose of our study was to assess the characteristics of oxidative metabolism in patients with malignant and benign tumor with and without a family history of cancer and identify the marker predicting the likelihood of malignancy.

[METHODS] We conducted a study on patients with thyroid pathology (thyrotoxicosis, benign tumor pathology of the thyroid gland, and thyroid cancer) who underwent treatment at LLC "Oncology Scientific Research Center" in Tbilisi, Georgia between 2020-2021.  In patients' blood the thyroid hormones content, the oxidative metabolism parameters (activity of nonenzymatic antioxidant system (TAA), malondialdehyde (MDA) content),  geometrical and rheological (deformability index (EDI), membrane proteins content) characteristics of erythrocytes were determined.

[RESULTS] in the patient's blood serum with benign tumor (47 patients) MDA exceeded (p<0.005) and TAA decreased (p<0.005) in comparison to the control level; in patients with thyroid cancer (35 patients), MDA also exceeded (p<0.005), while TAA increased (p<0.005) up to the control level. In patients with benign and malignant tumors, the size of erythrocytes increased compared to the control indicators (p<0.005); in patients with thyroid cancer and benign tumors with a family history of cancer (29 patients) EDI increased (p<0.005), content of GLUT1 in erythrocyte membranes decreased (p<0.005) compared to the control level.

[CONCLUSIONS] Alterations in redox metabolism play a crucial role in tumor formation; an imbalance between anti-/pro-oxidant systems may contribute to tumor formation and support its progression into a more malignant state. Thyroid cancer is characterized by a reduction in erythrocyte deformability, related to TSH levels. These alterations are less detectable in patients with benign thyroid tumors with a family history of cancer.