Relationship of Hashimoto's thyroiditis with papillary thyroid cancer: A clinical study

Abstract

Objective To evaluate the clinical relationship between Hashimoto's thyroiditis (HT) and papillary thyroid cancer (PTC).Methods A total of 5 440 patients underwent thyroidectomy in the Department of Endocrinology of Chinese PLA General Hospital from 2001 to 2011.Of these patients,1 709 patients with histologically confirmed PTC were analysed according to the presence or absence of concurrent HT.Several clinicopathological factors,such as age,gender,nodular size,invasive status,lymph node metastasis were compared between the two groups.Results (1) Of 5 440 patients with thyroid nodules,6.5％ (354/5 440) patients had concurrent HT.Compared with those without HT,a greater female preponderance (88.1％ vs 68.3％,P＜0.01),younger age [(45.40 ± 12.09 vs 47.47 ± 12.42) years,P＜0.01],smaller tumour size [(1.93 ± 1.46 vs 2.62 ±1.70)cm,P＜0.01],and higher prevalence of PTC were found in patients with HT (52.26％ vs 30.29％,P＜0.01).(2) Of 1 709 patients with PTC,10.8％ (185/1 709) patients had concurrent HT.Younger age at presentation[(41.77 ± 11.86 vs 44.08 ± 11.93) years,P＜0.05],a greater female preponderance (86.49％ vs 67.98％,P＜0.01),smaller tumour size [(1.34 ± 1.19 vs 1.58 ± 1.26) cm,P＜0.05],lower incidence of delayed treatment (7.0％ vs 16.8％,P＜0.01),and lower incidence of extrathyroidal extension (2.2％ vs 7.9％,P＜0.01)were noted in patients with HT compared with those without HT.(3) A multivariate analysis indicated that the presence of HT was a risk factor for PTC [OR =2.413,95％ CI 1.879-3.098,P ＜ 0.05].Conclusion Histologically confirmed HT is associated with a significantly higher risk of PTC,but the coexistence of HT in PTC cases may be associated with a better prognosis compared with those of PTC without HT. Key words: Hashimoto's thyroiditis; Papillary thyroid cancer; Thyroid nodules