Second primary cancer in patients with papillary thyroid carcinoma.

BACKGROUND AND AIM There is an increased incidence of secondary primary cancer (SPC) in patients with papillary thyroid carcinoma (PTC). The risk is stronger in the first year after the first malignancy (synchronous tumours). The aim of this study was to assess the prevalence of SPC in patients with PTC, and to analyse whether the timing of tumour presentation influenced the clinicopathological characteristics of PTC. PATIENTS AND METHODS A total of 184 patients with PTC were included in the study. RESULTS There were 24 patients with SPC and nine with PTC and two other primary tumours (42 additional malignancies in total). Additional tumours were more prevalent in male and older patients. In 11 cases (33%), the two carcinomas were synchronous. PTCs from synchronous cases were significantly larger than those from non-synchronous cases. CONCLUSION Patients with PTC were at elevated risk for SPC. In one third of patients, both neoplasms were diagnosed within the same year. Male and older patients were more likely to have SPC.