Hashimoto’s thyroiditis predicts outcome in intrathyroidal papillary thyroid cancer

Abstract

Hashimoto's thyroiditis (HT) seems to have favourable prognostic impact on papillary thyroid cancer (PTC), but data were obtained analysing all disease stages. Given that HT-related microenvironment involves solely the thyroid, we aimed to assess the relationship between HT, as detected through pathological assessment, and outcome in intrathyroidal PTC. This was a multicentre, retrospective, observational study including 301 PTC with no evidence of extrathyroidal disease. Primary study endpoint was the rate of clinical remission. Auxiliary endpoint was recurrence-free survival (RFS). HT was detected in 42.5% of the cohort and was associated to female gender, smaller tumour size, lower rate of aggressive PTC variants and less frequent post-surgery radio-iodine administration. HT showed relationship with significantly higher rate of clinical remission ( < 0.001, OR 4, 95% CI 1.78-8.94). PTCs with concomitant HT had significantly longer RFS, as compared with non-HT tumours ( = 0.004). After adjustment for other parameters affecting disease outcome at univariate analysis (age at diagnosis, histology, tumour size and multifocality), prognostic effect of HT remained significant ( = 0.006, OR 3.28, 95% CI 1.39-7.72). To verify whether HT could optimise the identification of PTCs with unfavourable outcome, we assessed the accuracy of 'non-HT status' as negative prognostic marker, demonstrating poor capability of identifying patients not maintaining clinical remission until final follow-up (probability of no clinical remission in PTCs without HT: 21.05%, 95% CI 15.20-27.93). In conclusion, our data show that HT represents an independent prognostic parameter in intrathyroidal PTC, but cannot improve prognostic specificity.

Associations between Hashimoto Thyroiditis and Clinical Outcomes of Papillary Thyroid Cancer: A Meta-Analysis of Observational Studies

“…The main characteristics of the 71 articles included in this meta-analysis are summarized in Table 1 [ 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 ]. A total of 44,034 participants with PTC were enrolled, of whom 11,132 (25.3%) had HT.…”

Is ultrasound combined with computed tomography useful for distinguishing between primary thyroid lymphoma and Hashimoto’s thyroiditis?

“…Therefore, the prognosis for thyroid lymphoma depends on staging, and early diagnosis is of vital importance [17][18][19][20][21]. When patients have coexistent HT with a rapidly growing thyroid mass or with symptoms of obstruction, a likely diagnosis may be HT with or without malignant lymphoma [22]. Ultrasound is a widely accepted diagnostic method for examining thyroid [23][24][25][26][27], but several studies have reported that it is less useful in differentiating between PTL and HT [28].…”

Papillary Thyroid Carcinoma Intertwined with Hashimoto’s Thyroiditis: An Intriguing Correlation

“…Irrespectively of whether HT is etiologically linked to PTC or merely judged "guilty by association," the importance of this coexistence lies on its clinical significance. Since a complex immune network has been considered a core component of PTC microenvironment, it is rational to assume that HT-the epitome of aberrant immune reaction-influences the progression of coexistent PTC [105]. In that respect, the positive association of a favorable outcome of coexistent PTC with HT, tumor-associated macrophage infiltration, and CD8+ lymphocytes highlights the antitumor potential of the immunological landscape intrinsic in HT [106].…”

“…The results of a recent meta-analysis including 71 published studies with 44,034 participants revealing that PTC coexistent with HT significantly correlated with reduced incidence of extrathyroidal extension, lymph node, and distant metastasis and increased recurrence-free survival duration compared with PTC alone are seminal [47]. Noticeably, the coexistence of HT with PTC has been proven an independent indicator of favorable prognosis of PTC [105], irrespectively of the extent of lymph node dissection [46], though inconsistently [108]. On the other hand, the reported absence of host-protective effect of HT on coexistent PTC [42-45] hampers the endorsement of HT as a prognostic PTC biomarker.…”