Association of Elevated Levels of Some Intra-Thyroidal Trace Elements with Goiter and Cancer Risk of Female Thyroid

Introduction: Advancing age is known to influence the formation of adenomatous goiter and thyroid cancer. An excess or deficiency of specific TEs contents in thyroid can play an important role in goitro- and carcinogenesis of this gland. Objective: This study aimed to assess the variation with age of fifty trace element (TE) contents in normal female thyroid. Methods: Samples of the human thyroid were obtained from randomly selected autopsy specimens of 33 females (European- Caucasian) aged 3.5 to 87 years after a sudden death mainly from trauma. The mass fractions of TEs in normal female thyroids were investigated using neutron activation analysis and inductively coupled plasma mass spectrometry. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for TEs analysis. Results: This work revealed that there is a statistically significant increase in Co, Cs, Fe, La, Pb, Rb, Sb, Se, Sn, Tl, and Zn mass fraction in the normal thyroid of female during a lifespan. Contents of such carcinogenic or potentially carcinogenic TEs as Co, La, Pb, Sb, Sn, and Tl in thyroid of seniors are 5-10 times higher than those in thyroid of girls or young women. Conclusions: From results of our study, a goitrogenic and carcinogenic effect of elevated Co, Cs, Fe, La, Pb, Rb, Sb, Se, Sn, Tl, and Zn levels in the thyroid of elderly females is shown to be a very likely consequence.