Synchronous and antecedent nonthyroidal malignancies in patients with papillary thyroid carcinoma

There is a known association between the development of papillary thyroid cancer (PTC) after a primary nonthyroidal cancer (NTC). However, the prevalence of synchronous or antecedent NTCs in patients with PTC is undetermined, as are the clinicopathologic characteristics of PTC in these patients.

A review was performed of our prospectively maintained PTC database between January 1995 and December 2010. Information collected included patient and tumor characteristics, medical history, PTC presentation, and treatment modality.

Four hundred and thirty-three adult patients underwent thyroid resection and had PTC on final pathology. Sixty-seven cases of synchronous or antecedent NTCs were observed in 60 patients (13.9%). The most commonly associated antecedent NTCs were breast (n = 11), prostate (n = 8), and melanoma (n = 5), whereas renal cell carcinoma (n = 3) and melanoma (n = 3) were the synchronous NTCs most observed. Compared with patients without an NTC, those with an NTC were older (56.4 ± 15.5 years vs 44.9 ± 14.2 years; p < 0.0001), had experienced radiation exposure (35.0% vs 3.5%; p < 0.001), and more commonly presented with a thyroid mass incidentally on imaging (41.7% vs 9.1%; p ≤ 0.001). Papillary thyroid cancer tumor characteristics were similar between groups, except that NTC patients presented at a more advanced stage. However, when analyzed independently, primary tumor size, and nodal and distant metastases were comparable.

The prevalence of synchronous or antecedent NTCs in patients surgically treated for PTC is 13.9%. These patients present with PTC tumor characteristics similar to those without additional NTCs, and should therefore be managed equivalently. In addition, surgeons should be aware of the frequency of synchronous PTC with these types of tumors and consider evaluation of the neck at the time of NTC diagnosis.