Hashimoto’s Thyroiditis Effects on Papillary Thyroid Carcinoma Outcomes: A Systematic Review

Abstract

Papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT), also known as chronic lymphocytic thyroiditis, are both common thyroid diseases that are increasing in prevalence. PTC is well-differentiated cancer that generally has an excellent prognosis. HT is an autoimmune disease that often leads to hypothyroidism. A significant proportion of PTC patients also have HT. This systematic review will analyze the effect of HT on the characteristics and outcomes of PTC.Several databases were systematically searched using relevant medical subject headings (MeSH) keywords and phrases examining the connection between PTC and HT and the effect of their coexistence. Inclusion and exclusion criteria were applied, followed by quality appraisal. After that filtration process, 23 articles were selected with a total of 41,646 patients.Out of 22 studies commenting on tumor size, 12 studies demonstrated it to be smaller in HT patients, while 10 studies observed no effect. Eleven studies examined PTC angioinvasion, most of which found no difference in HT and non-HT patients. However, two studies found angioinvasion to be reduced in PTC patients. As for capsular infiltration, out of the five studies commenting on it, two found decreased occurrence, one found increased occurrence, and two had no difference. Extrathyroidal extension was found to be reduced in seven studies out of the 14 that examined it. Six other studies saw no effect. One study found increased extrathyroidal extension incidence overall, and another found it to be the case in patients younger than 45 years of age. Lymph node metastases were found to be reduced in several studies, while others found no difference. One study found increased central lymph node metastases in HT patients. As for prognoses, most studies found positive aspects. One study found an increased recurrence rate in HT patients, however, it did not have a relationship with deaths.In conclusion, when managing HT or HT and PTC patients, HT patients should be monitored closely for suspicious nodules due to their frequent co-occurrence. Although the effect of HT on PTC has been shown to be mostly protective, multifocality is more common in those patients and, therefore, a total thyroidectomy should be favored. The high false positive rates of lymph node metastases in diagnostic methods should be kept in mind when considering lymph node dissection. Additional diagnostic procedures such as frozen section histology should be considered for verification.

The impact of nodule size on malignancy risk in indeterminate thyroid nodules

“…In addition, the aggressiveness features (except lymph node metastasis) were more likely to be found in nodules <4 cm than in those ≥4 cm; although not statistically significant, these differences are in line with a previously published study ( 4 ). Furthermore, the presence of thyroiditis was associated with nodules <4 cm, which is in accordance with the study by Osborne et al ( 23 ).…”

Comparison of Various Ultrasound-Based Malignant Risk Stratification Systems on an Occasion for Assessing Thyroid Nodules in Hashimoto’s Thyroiditis

“…The higher prevalence of PTC in patients with HT was similar to those of some previous studies. 10 , 28 The rate of lobulated or irregular margin was comparable between malignant and benign thyroid nodules in the HT background, which raised the difficulty of US in evaluating thyroid cancer in HT patients. The ATA guidelines had the highest sensitivity, and the ACR guidelines had the highest specificity in patients with and without HT.…”

Interaction of BANCR in the relationship between Hashimoto’s thyroiditis and papillary thyroid carcinoma expression patterns and possible molecular mechanisms

“…This autoimmune condition triggers inflammation within the thyroid gland and can lead to hypothyroidism. Recent investigations have demonstrated a noteworthy association between HT and an elevated risk of developing thyroid cancer, particularly PTC 30 . Hence, it becomes imperative to delve into potential biomarkers and therapeutic targets for both PTC and HT.…”

“…Recent investigations have demonstrated a noteworthy association between HT and an elevated risk of developing thyroid cancer, particularly PTC. 30 Hence, it becomes imperative to delve into potential biomarkers and therapeutic targets for both PTC and HT. Consequently, this study aimed to elucidate the involvement of BANCR in the interplay between HT and PTC by scrutinizing its expression patterns in these diseases.…”