Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm

Abstract

PurposeTraditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm.MethodsA retrospective study was performed including patients from 17 centers in 5 countries. Adults diagnosed with DTC stage T1b-T3 N0-1a M0 who all underwent a total thyroidectomy were included. The primary endpoint was the presence of a contralateral carcinoma.ResultsA total of 1313 patients were included, of whom 426 (32 %) had a contralateral carcinoma. The contralateral carcinomas consisted of 288 (67 %) papillary thyroid carcinomas (PTC), 124 (30 %) follicular variant of a papillary thyroid carcinoma (FvPTC), 5 (1 %) follicular thyroid carcinomas (FTC), and 3 (1 %) Hürthle cell carcinomas (HTC). Ipsilateral multifocality was strongly associated with the presence of contralateral carcinomas (OR 2.62). Of all contralateral carcinomas, 82 % were ≤10 mm and of those 99 % were PTC or FvPTC. Even if the primary tumor was a FTC or HTC, the contralateral carcinoma was (Fv)PTC in 92 % of cases.ConclusionsThis international multicenter study performed on patients with DTC larger than 1 cm shows that contralateral carcinomas occur in one third of patients and, independently of primary tumor subtype, predominantly consist of microPTC.

Prevalence of Contralateral Tumors in Patients with Follicular Variant of Papillary Thyroid Cancer

“…In both series, cancer rates were higher than expected, although it is interesting to note that we found a considerably higher rate of incidental cancers in our fvPTC cohort (53% multifocal and 35% contralateral). Two other studies identified comparably high rates (46.4% [125 of 269 patients] 26,27 Taken together, these data suggest that the rate of unsuspected incidental cancer is quite high, especially in the presence of a known cancer diagnosis. Consequently, patients who present with contralateral nodules >1 cm during preoperative workup should undergo FNA sampling to rule out synchronous cancers before surgery.…”

Long-term outcome of thyroid lobectomy for unilateral multifocal papillary carcinoma

“…[1,11–13] However, it is unreasonable to perform total thyroidectomy in all patients when only a few may have contralateral occult carcinoma and therefore most patients might become victims of over-treatment. Moreover, the incidence of hypoparathyroidism and recurrent laryngeal nerve injury are higher after total thyroidectomy than lobectomy.…”

“…[2,8–13] However, studies for the influence of surgical range on prognosis of unilateral multifocal carcinoma are scarce. [9,10] …”

Is it time to reconsider lobectomy in low‐risk paediatric thyroid cancer?

“…To this end, small studies have indicated that the presence of contralateral disease does not impact recurrence and that performing total thyroidectomy does not prevent recurrence in patients with multifocal disease . Furthermore, studies in adults have raised doubts about the clinical relevance of tumour multifocality, showing that these are often not a reflection of intraglandular metastasis but rather represent incidental synchronous micro‐PTC . Similar molecular studies may be considered in the paediatric population to gain insight into the pathophysiology of multifocality.…”

“…9,10 Furthermore, studies in adults have raised doubts about the clinical relevance of tumour multifocality, showing that these are often not a reflection of intraglandular metastasis but rather represent incidental synchronous micro-PTC. 11,12 Similar molecular studies may be considered in the paediatric population to gain insight into the pathophysiology of multifocality.…”