The prognostic role of Hashimoto's thyroiditis in papillary thyroid carcinoma: insights from a single-center cohort study.

[BACKGROUND] Hashimoto's thyroiditis (HT) is the most common autoimmune thyroid disorder, while papillary thyroid carcinoma (PTC) is the most prevalent thyroid malignancy. The association between HT and PTC remains debated, with some studies suggesting a protective effect of HT against aggressive PTC features. This study explores the relationship between HT and PTC in a single-center cohort, focusing on clinicopathological and prognostic factors.

[METHODS] This retrospective study included adult patients who underwent thyroid surgery between 2009 and 2017. Patients were divided into two groups: those with concurrent PTC and HT (Group 1,  = 68) and those with PTC alone (Group 2,  = 329). Demographic, laboratory, and pathological data were compared using appropriate statistical analyses.

[RESULTS] A significant association between HT and PTC was observed (χ=5.3;  = 0.021; OR: 1.682). Group 1 patients were more often female and significantly younger. TSH levels were higher in Group 1 ( < 0.001), and follow-up duration was longer ( = 0.023). Although the mean tumor diameter was smaller in the HT group, the difference was not statistically significant. No significant differences were found regarding multifocality, capsular invasion, or lymphovascular invasion.

[CONCLUSION] The presence of HT appears to be significantly associated with the occurrence of PTC and may be linked to a less aggressive clinical profile, as suggested by younger age and higher TSH levels. The longer follow-up duration observed in HT patients may reflect more vigilant surveillance due to underlying autoimmune pathology. However, the retrospective and single-center design limits generalizability. Prospective, multicenter studies with larger cohorts are warranted to confirm these findings.