Association of Hashimoto Thyroiditis (HT) with Papillary Thyroid Cancer (PTC)

Introduction Hashimoto thyroiditis (HT) is the most common autoimmune disease of thyroid gland. It characterized by a gradual autoimmune destruction of thyroid parenchyma with consequently thyroid failure with occasionally thyroid goiter. Its more prevalent in females than males. The same is for papillary thyroid cancer (PTC) is the most prevalent form of thyroid cancer and is more prevalent in females than males. Association between HT and PTC is controversial and still an open debate. So we undertook this study to determine the association between HT and PTC. Material and methods In a retro and prospective study we analyzed the date of 155 patients 128 (82.5 %) females and 27 (17.5 %) males who underwent total or near total thyroidectomy for any thyroid pathology from April 2011 until April 2016. Results HT was found in 30 (19, 3 %) of the 155 patients, (27 females and 3 males). Papillary thyroid cancer was found in 70 (46, 4 %) of 155 patients, (60 female or 85, 7 % and 10 males or 14, 3 %). Co association of PTC with HT was found in 17 (10, 9 %) of 155 patients, (15 females, 88, 3 % and 2 males 11, 7 %). Among the group of PTC 70 patients, the prevalence of HT was 24, 2 % (17 patients), 15 females (88, 2 %) and 2 males (11, 3 %), which was higher than the prevalence of HT in other patients without PTC (15, 3 %), 12 females (92, 3 %) and one male (7, 7 %). Among of 30 patients with HT prevalence of PTC was 56, 6 % (17 patients), which was higher than the prevalence of PTC in other patients without HT (42, 4 %). However, there was no statistically significant difference (2 =1.98, df=1, p=0.15) between the presence of PTC in specimens with HT and the presence of PTC in other HT negative patients. There was no significant difference in age (Chi-Sq 0, 0005, p=0, 18), at the time of diagnosis between PTC patients with and without HT. there is a significant difference in tumor size between patients with or without HT (Chi-Sq 7, 800, p=0, 02). Prevalence of microcarcinoma was higher in patient with HT than non HT 28, 3 %, versus 7 % with a statistically significant difference (Chi-Sq =7, 30 df=1, p=0.006). HT was more often observed in multifocal PTCs than in single PTCs (P=0, 07). Conclusion In conclusion, the existing data provide inconsistent evidence favoring a causal relationship between HT and PTC. For the moment there is no valid criteria to identify those patients with HT which are at high risk for developing PTC. Careful observation and close follow-up of HT patients with nodular structure is recommended